CONTACT : MOHD RAFII YUSOP        mrafii@upm.edu.my 
 
 

1 
 

Abstract 
Rice (Oryza sativa L.) is a cereal and staple food crop of over half of the world’s 
population. Blast, bacteria leaf blight and drought stresses affect yield of rice 
drastically ranging from 1-100% loss depending on the severity of disease and 
water deficit condition. Resistance and tolerance high yielding varieties of blast 
(Putra1) and drought (MR219 IR99784-156-137-1-3) respectively and also 
IRBB60 (bacteria leaf blight) were used. The research considered the genetic 
inheritance of the new improved lines and their interactions. Pedigree breeding 
method was used to develop two single, double and three-way (and reciprocal) 
crosses through marker-assisted selection. Southern blot analysis was used to 
determine success of introgression of resistance/tolerance genes/QTLs and 
selection, also validated by phenotyped results. Agro-morphological and yield 
parameters of the various populations were analysed. The results indicated 
levels of significant differences amongst and between treatments for non-
drought stress (NS) and reproductive drought stress (RS) and their interactions. 
There were significant variation among parents and improved lines on some 
traits in NS treatment, but RS significantly affected parameters of DF, FFG, YM 
and most especially the susceptible parent, while the improved lines were 
tolerant.  Significant interactions was recorded (P≤0.05) between treatment and 
variety (Trt*Var.) on PL, T, FFG and GLW. Cluster analysis and PCA of relationship 
among the 9 traits in the two treatments revealed that each of single, double 
and three-way (and reciprocal) crosses had good lines either under NS and RS. 
  
 
 
 
 

ISSN : 2580-2410 
eISSN : 2580-2119 

 
 

 

Genetic inheritance of multiple traits of blast, bacteria leaf blight 
resistant and drought tolerant rice lines 
 
Ibrahim Silas Akos1,2, Mohd Rafii Yusop*1,3, Mohd Razi Ismail1,3, Shairul Izan Ramlee3, 
Noraziyah Abd Aziz Shamsudin4, Asfaliza Binti Ramli5, Jalloh Momodu1, Jamilu Halidu1, & 
Senesie Swaray1 
 
1Laboratory of Climate-Smart Food Crop Production, Institute of Tropical Agriculture and 
Food Security, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. 
2Department of Crop Science, Faculty of Agriculture, Kaduna State University, Kafanchan 
Campus, Nigeria. 
3Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400 UPM 
Serdang, Selangor, Malaysia. 
4School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, 
Universiti Kebangsaan Malaysia. 
5Malaysian Agricultural Research and Development Institute, Rice Research Centre, 
Persiaran Mardi-UPM, 43400, Serdang, Selangor, Malaysia. 
 

 
 
  
  
 
 
 
 
 
 
 
 
 
 
 
 

        OPEN ACCESS             International Journal of Applied Biology 

Keyword 
Rice,  
Genetic,  
Inheritance,  
Resistant,  
Tolerance. 
 

Article History 
Received 25 September 2019 
Accepted 29 December 2019 

International Journal of Applied Biology is licensed under a 
Creative Commons Attribution 4.0 International License, 

which permits unrestricted use, distribution, and reproduction 

in any medium, provided the original work is properly cited.  

 



                  

International Journal of Applied Biology, 3(2), 2019 

 
 
          2 
 

Introduction 
Rice, a multi-environmental (rain-fed lowland, upland and deep water) (Ou, 1985, Latif 

et al., 2011) cereal and staple food crop of the world, it is one of the most cultivated crops 
along with wheat and corn. It provides nutrient and meets the economic need of the farming 
populace. It is consumed by over 50% of the world’s population as their major source of 
calorie (Luo et al., 1998). Blast and bacteria leaf blight are two major important diseases of 
rice that causes significant yield loss to farmers (Asghar et al., 2007, Jia et al., 2000, Zhang et 
al., 2015).  

The management practice for the disease can be fungicide, biotechnological methods, 
agronomic practices and cultivation of resistant cultivars (Ribot et al., 2008). The use of the 
resistant variety is the most environmental and economically friendly approach to blast threat 
(Castano et al., 1990, Saifullah et al., 1995, Khan et al., 2001, Haq et al., 2002). The challenge 
is often that due to the changeful nature of the virulent races, the resistance traits may be 
lost in the cause of time. The most effective strategy to minimize yield losses due to blast, 
bacteria leaf blight and drought stress is through the development of durable, broad-
spectrum resistant varieties (Jena and Mackill, 2008; Kumar et al., 2014; Sundaram et al., 
2014). Sundaram et al. (2014) reported that atleast 40 genes that confer bacteria blight 
resistance have been identified, while many have been fine-mapped and cloned (Natrajkumar 
et al., 2012). 101 blast resistant (R) genes (Rajashekara et al., 2014) and 350 QTLs have been 
identified (Sharma et al., 2012). Closely linked markers available for many blast resistance and 
bacteria blight genes have been identified (Sundaram et al., 2014). Drought stress is a 
condition of water availability deficit, it could be water deficit condition at any of the stages 
of rice development which has the potential of affecting yield. Drought stress is increasingly 
becoming a challenge to farming communities today with a global scale, it affects over 
23million hectares of farming areas in Asia (Bray et al., 2000; Kumbhar et al., 2015). The 
increasing human population with approximated 10billion by the year 2050 also requires 50% 
increase to current global rice production to meet the food projection demand (Maclean et 
al., 2002, Bourman et al., 2007). This places a demand for strategy to increase yield 
production in the phase of climate change to develop rice adapted to drought stress (Pandey 
and Sukla, 2015). Understanding plant diversity in relation to behaviour and adaptation of 
drought-prone environment is important (Alonso-Blanco et al., 2009), the ability to design an 
effective strategy of phenotyping requires good understanding of plant survival mechanism 
under drought stress. 

Understanding of plant diversity is relevant to assessment of genotypic variability 
under different water deficit condition as an important pre-condition for a successful drought 
tolerance breeding programme (Sarkar et al., 2013, Abenavoli et al., 2016, Anower et al., 
2017). Blast, bacteria leaf blight (BLB) and drought stress could affect rice drastically, and 
result showed that high incidences caused yield losses of 100% (Zhai and Zhu, 1999), 1-50% 
(Scardaci et al., 2003) and 100% depending on the stage of rice development and duration 
respectively. 50% yield loss was recorded for abiotic stress (Bray et al., 2000, Iqbal et al., 2013, 
Li et al., 2014). 

The parameters of panicle length, effective tillers, grain length and width ratio, 100 
grain weight, fully grain weight were amongst those considered important agronomic trait 
which has correlation with increased yield potential in rice, considered as quantitative traits 
which could be affected  by the influence of environment (Han et al., 2004, Guo et al., 2003, 
Han et al., 2006, IRRI-SES, 2013, Taglea et al., 2016, Chang et al., 2016).New improved lines 
has been developed with three resistance/tolerant traits of blast (Magnaporthe grisea) 



                  

International Journal of Applied Biology, 3(2), 2019 

 
 
          3 
 

bacteria leaf blight (Xanthomonas oryzae) and drought tolerance (MR219) through 
pyramiding of marker-assisted selection. This research considered the genetic inheritance of 
the target genes and their interactions. 

 
Materials and Methods 
Plant material and breeding design  

Plant materials used were new developed lines from three parents with resistances to 
blast, M. grisea anomorph P. oryzae, a popular Malaysia high yielding rice variety known as 
Putra1. Bacteria leaf blight resistance variety known as IRBB60, and a drought tolerant 
Malaysia variety referred to as MR219 (IR99784-156-137-1-3 Drought tolerance). these 
varieties were developed as single crosses, double cross and three-way cross with reciprocal 
cross as well. These new lines were developed in a glass house at Rice Research Centre and 
Laboratory of Climate and Smart-Food Crop Production, Universiti Putra Malaysia. 
 
DNA extraction and nanodrop spectrophotometry 

Three-four weeks old leaves samples were collected and ground using mortar and 
pestle in liquid nitrogen. The procedure was according to Doyle and Doyle (1987) 
cetyltrimethylammonium bromide CTAB method with modification following the protocol of 
McCouch et al (1988).  

The DNA pellet was diluted in 50µl TE buffer, 2µl was pipetted on nanodrop 
spectrophotometry machine to measure the quantity and purity of the DNA samples. This 
formed the basis for the constitution of the DNA working solution for polymerized chain 
reaction (PCR) amplification. 

 
Molecular markers 

Simple sequence repeat (SSR) markers polymorphic and linked to the genes/QTLs for 
the three parental varieties were purchased. Putra1, a blast resistance variety had two 
polymorphic markers that were also linked to the genes of resistance (R), MR219 (IR 99784-
156-137-1-3) drought tolerance variety used had three qDTY and IRBB60 had four R genes 
(Pinta et al. 2013, Miah et al. 2016, Kumar et al. 2014, Khan et al. 2015, Pradhan et al. 2015, 
Shamsudin et al. 2016, www.gramene.org). 

 
Polymerized chain reaction and electrophoresis 

The pairs of primers for the various genes/QTLs were optimized to amplify simple 
sequence repeat loci for polymerase chain reaction (PCR). Survey of the three parental 
varieties was carried out to identify SSR markers polymorphic to each of them. Total PCR 
reaction of  15μL which contained 70ng DNA template  had 7.5μL master mix (Thermo 
Scientific, Waltham, MA, USA), 4.5μL nucleaus free water and 1.0 μmol L-1 concentration of 
each primer (Forward and Reverse). The PCR amplification was conducted in a thermocycler 
(T100TM, Bio-Rad, Hercules, CA, USA) following the touchdown protocol with the lid 
temperature of 1050C. The initial denaturation, annealing and extension temperatures were 
thus; 940C for 3mins followed by 940C for 30sec, a temperature of 620C for 1min., +10C per 
cycle followed by 720C for 30sec., then a returned to step 2, 9× followed by 940C, 30sec., 520C, 
1min, 720C, 2mins., another return to step 6, 29×., and finally 720C, 10mins. Followed by rapid 
cooling to 40Cꝏ prior to analysis. 

http://www.gramene.org/


                  

International Journal of Applied Biology, 3(2), 2019 

 
 
          4 
 

Southern blot analysis using gel electrophoresis was carried out. 2.0% MetaphorTM 
agarose (Lonza) gel containing 5μL Midori green in 1× TBE buffer (0.05 mol L−1 Tris, 0.05 mol 
L−1 boric acid, 1 mmolL−1 EDTA, pH 8.0) was run with 5μL of PCR product mixed with loading 
dye. The gel run was at a constant voltage of 80V for 45-60 minutes. Molecular imager system 
(GelDocTM XR, BioRad) was used to analyzed band pattern under UV light for amplified 
products. 

 
Identification of polymorphic markers and progeny selection  

The basis for a successful marker-assisted selection was the identification of the 
polymorphic markers for each of the parent trait. Blast resistance had RM6836 and RM8225, 
IRBB60 had Xa13 prom, RM122, RG136, pTA248 and RM224 while MR219 IR99784-156-137-
1-3 drought tolerance had RM511, RM1261 and RM520 polymorphic to the drought tolerance 
QTLs. 

Two F1s with double bands corresponding with the parent plants were selected, that 
was in a cross between a common recipient parent Putra 1 and donor IRBB60, Putra1 and 
MR219. The selected progenies formed the bases for a double cross and three-way and 
reciprocal crosses. 

The selection of the subsequent generations of F1(2) and F1 three-way crosses were 
based on southern blot analysis of the bands which coincide with the first recipient and the 
introgressed variety. Those were selected and advanced until a non-segregating F3(2) double, 
F4 single, and F3 three-way crosses pure-line generation was reached. 
 
Fungal, bacteria culture and inoculation 

Most virulent strains of fungus Magnaporthe grisea pathotype P7.2 and bacterium 
Xanthomonas oryzae pv oryzae MX01552 were obtained from Malaysia Agricultural Research 
and Development Institute (MARDI). They were sub-cultured in potato dextrose agar (PDA) 
for 14 days in 250C and nutrient agar (NA) for two days in 300C respectively (Suresh et al. 
2013, Mahdieh et al. 2013). 

The M. grisea mycelia culture was prepared in sterile distilled water suspension at 
concentration of 1.9×106 conidia mL-1. The Xoo culture was also prepared in a suspension 
concentration of 109. 

The fungus suspension was sprayed on young leaves of 2-3 weeks old at relative 
humidity >90% for 48hours for disease infection and after 7 days disease scoring was carried 
out according to the IRRI-SES, (2013) glass house scoring, thus; from 0-2, resistant (R), 3 
considered as moderately resistant (MR) and score 4-6 as MS, while 7-9 as S. The Xoo 
pathogen was clip inoculated on 3-4 weeks old leaves at 1-2cm from the tip of the leaves. The 
scoring was by measuring the length of infected area with meter rule in centimeter according 
to IRRI-SES, 2013. Glass house scale (Banito et al. 2012) and modification according to 
Amante-Bordeos et al. (1992), thus; 0-5 considered as R, >5-10 MR, >10-15 MS, while >15 
were considered as S.  

 
Drought stress imposition 

Reproductive drought stress was imposed on the rice lines carrying drought tolerance 
QTLs. According to IRRI-SES (2013) one week of water deficit stress for glass house experiment 
is enough to affect yield. The reproductive stage was between 70-90 days after sowing. Stress 
was imposed for >2weeks with leaves turned from U-shaped to 0-shaped as criterion for 



                  

International Journal of Applied Biology, 3(2), 2019 

 
 
          5 
 

scoring drought (IRRI-SES, 2013, Kadioglu and terzi, 2007), dried soil and soil moisture meter 
with >15cm depth measured dried. 

 
Experimental layout and cultivation 

The experiment was set out in a glass house at Rice Research Centre, Universiti Putra 
Malaysia with 3 plants each per bucket and label accordingly. The leaves of the parents to 
their progenies were collected and genotyped using southern blot analysis to determined the 
ideal plants for selection until line stability of the progenies as non segregating generation 
reached. The non-segregating (pure-lines) and parent plants were laid in rows according to 
their genotypes. 

 
Data collection 

Nine quantitative traits were measured and data collected from the 3 parents and 
their progenies (improved lines) in single trial under non drought stress (NS) and reproductive 
drought stress (RS) treatment in five (5) replications in around 120 days after seeds sowing. 
These quantitative traits included; days to 50% flowering (DF), height of plant (HP), panicle 
length (PL), effective tillers (ET), tillers produced (T), fully filled grain (FFG), 100-grain weight 
(100-GW), grain length and width ratio (GLW) and yield maturity(YM) as indicated in Table 4. 
for NS and Table 7. for RS treatments. 

  
Statistical Analysis 

All evaluated data were subjected to analysis of variance (ANOVA) using Statistical 
Analysis Software (SAS) version 9.4 in Complete Randomized Design (CRD). The expressed 
results were in mean, mean square, correlation coefficient (CV) and standard deviation to set 
the relationship among the parameters (traits). To determine the genetic variability among 
the 9 quantitative traits, cluster analysis was employed. The genetic relationship among the 
parent varieties and improved rice lines was determined in conformity with unweighted pair 
group method using arithmetic average (UPGMA) algorithm and sequential, agglomerative, 
hierarchic and non-overlapping (SAHN) method using Numerical Taxonomy Multivariate 
Analysis System, Exeter Software, Setauket, NY, USA software (NTSYS v2.1). 
 
Table 1. Description of major symbols 

Symbol Description 
PB 
PD 
PBD 
 
PDB 
DPB 
 
DF 
HP 
 
PL 
ET 
T 
FFG 
 
GLW 
100GW 

Cross between Putra1 and IRBB60 
Cross between Putra1 and MR219 
Three-way cross between putar1 and IRBB60(F1) and 
MR219 Drought tolerant 
Double cross(from two F1s; P×D and P×B 
Three-way reciprocal cross (between MR219 drought 
tolerant and F1 Putra1×IRBB60) 
Days to 50% flowering 
Height of plant measured from the base to the tip of 
panicle 
Panicle length measured in centimetre 
Effective tiller refers to those that had gains 
Total number of tillers produced 
Fully filled grain obtained by counting the number of 
grains produced per panicle 
Grain length and width ratio of a grain 
100grain weight is a measure of 100 grains in grams 



                  

International Journal of Applied Biology, 3(2), 2019 

 
 
          6 
 

 
 
 
 

 

Results and discussion 
Genotypic and phenotypic selection of improved lines 

Electrophoresis analysis (gel scoring) results with bands showing alignment to the 
recipient parents were selected as pure and non-segregating lines in the F4 single crosses for 
PD and PB, F3 three-way and reciprocal crosses (PBD, DPB) and F3(2) (double) cross (PDB) as 
shown in the Figures 1, 2, 3, 4 and 5 below. 

Challenging the plants with the disease pathogens and subjection to water deficit 
stress for the improved lines and susceptible varieties was undertaken. The results showed 
that the improved lines were resistant and moderately resistant to blast and bacterial leaf 
blight and as well tolerant to drought stress according to acceptable yield percentage for 
tolerant rice (Miah et al. 2016, Ashkani et al. 2011, Yambao and Ingram, 1988). The 
susceptible varieties in each case were truly susceptible to the disease pathogens and drought 
stress.  

 

Figure 1. F3(2) cross for improved lines(PDB)  

 

Figure 2. F3 three-way reciprocal cross of improved lines(DPB) 

 

Figure 3. F3 three-way cross of improved lines PBD 

YM 
 
DS 
NS 

Yield maturity is the number of days from sowing to 
harvest. 
Reproductive drought stress 
Non-drought stress 



                  

International Journal of Applied Biology, 3(2), 2019 

 
 
          7 
 

 

Figure 4. F4 single cross improved lines(PD) 

 

Figure 5. F4 single cross for PB improved lines 

 
Agronomic trait assessment of improved lines 

These are also considered as  agronomic traits; days to 50% flowering, height of plant, 
panicle length, number of tillers, effective tillers, fully filled grain, 100-grain weight, grain 
length and width ratio, yield maturity. The effect of blast, bacteria leaf blight and drought on 
any of these parameters could result in poor yield and quality. Improved lines were evaluated 
under two treatments condition, namely; non-drought stress (NS) and reproductive drought 
stress (RS) condition. Under NS the data of both parents and improved lines were analysed, 
whereas in RS treatment, a susceptible and improved lines were analysed. They were to 
further validate the results of the southern blot analysis (genotyping) and the phenotyping 
results that showed resistances and tolerance to blast, bacteria leaf blight (BLB) and drought. 



                    
 
 

8 
 

Table 2. Polymorphic, linked/quantitative trait loci and flanking simple sequence repeat (SSR) markers for genes/QTLs used. 

 
 
 

 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
 
 
 

Variety SSR markers Genes/QTLs Chromosom
e position 

Expected 
base pair size 

Description 

Putra1 
Blast resistance 

 
RM6836 

 
Piz, Pi2, Pi9 

 
6 

 
240 

 
Polymorphic/linked 

 RM8225 Piz 6 221 Polymorphic/linked 
IRBB60 
Bacteria leaf blight resistance 

  
RM224           

 
Xa4 

 
11 

 
157 

 
Polymorphic/linked 

 RM122 
RM153 
RM13                   

xa5 
xa5 
xa5 

5 
5 
5 

227 
201 
141 

Polymorphic/linked 
Linked 
Polymorphic/linked 

 RG136 
Xa13Prom           

xa13 
xa13 

8 
8 

246 
 

Polymorphic/linked 
Polymorphic/linked 

 RM21   
pTA248  
               

Xa-21 
Xa-21 

11 
11 

157 Polymorphic/linked 
Polymorphic/linked 
 

MR219 IR99784-156-137-1-3 
Drought tolerance 

 
RM511 

 
qDTY12.1 

 
12 

 
130 

 
Polymorphic/linked 

 RM1261 qDTY12.1 12 167 Polymorphic/flanking marker 
 RM28099 qDTY12.1 12 120 Flanking marker 
 RM28076 qDTY12.1 12 287 Flanking marker 
 RM520 qDTY3.2 3 247 Polymorphic/linked 
 RM236 qDTY2.2 2 174 Linked 
 RM276 qDTY2.2,3.1 6 149 Flanking marker 

Askani et al., 2011, Miah et al., 2016, Shamsudin et al., 2016, www.gramene.org, He et al, 2006, Khan et al., 2015, Pradhan et al., 

2015 

 

http://www.gramene.org/


International Journal of Applied Biology, 3(2), 2019 

                                                               9 
 

Table 3. ANOVA for the parameters showing level of significance for non-drought stress (NS) 
 

SOURCE DF DF(no) HP(cm) PL(cm) ET(no) T(no) FFG(no) 100GW(no) GLW(cm) YM(days) 

Var 13 6.15* 73.9** 33.39*  13.73ns 16.90** 336.66* 0.02** 0.61** 3.48* 

Rep. 4 3.31ns 50.4ns 0.28ns 2.13ns 5.32ns 239.19ns 0.02ns 0.07ns 2.19ns 

Error 52 3.13ns 24.6ns 1.04ns 5.31ns 5.33ns 117.92ns 0.009ns 0.1ns 1.52ns 

C. TotaL 69          

∗Significant at P≤0.05, ∗∗highly significant at P≤0.01, ns: non-significant P> 0.05, DF. (degree of freedom), Var. (Variety), REP. (Replications),  
C. Total (Corrected total), DF (Days to 50% flowering), HP (cm) (Height of plant measured in centimetres), PL (Panicle length in centimetres),    
ET (Effective tillers), Tillers (total number of tillers), FFG (Fully filled grains), 100-GW (100 grain weight in grams) 

 
 
 
 
 
 
 
 
 
 
 
 
 



International Journal of Applied Biology, 3(2), 2019 

                                                               10 
 

 
Figure 6. Comparison of agro-morphogical and yield parameters of parent plants and their progenies (improved lines) in non-

drought stress condition 
 
 
 
 
 
 
 
 
 
 

0

20

40

60

80

100

120

140

160

180

200

M
e
a
n
 

Parent plant and progenies

Mean comparison of agro-morphogical and yield parametersbetween parents and progenies in non-
drought stress condition 

DF

HP

PL

ET

T

FFG

100GW

GLW

YM



International Journal of Applied Biology, 3(2), 2019 

                                                               11 
 

Table 4. Mean squares, least significant differences, coefficient of variations, standard deviation and broad sense heritability of 
vegetative traits and yield components of different rice varieties (genotypes) for reproductive drought stress and non drought stress 
treatments. 

 

VARIETIES 
 

DF(no)              
RS    NS 

       HP(cm)             
RS    NS 

PL(cm) 
NS   RS 

ET(no) 
NS    RS 

T(no) 
NS    RS 

FFG 
NS    RS 

PUTRA1 89a - 103.19c - 
25.03a
b - 10.2bcd - 10.6bcde    - 172.8ab - 

DROUGHT 88ab - 100.3c - 25.9ab - 13.6a - 13.8a          - 168.4abc - 

IRBB60 87.8abc 96.6a 103.61c 97.52a 25.06b 20.68c 7.8de 9ab 8.8de       9.6ab 172.4ab 26.4c 

PB12 87.6abc - 104.34c - 24.9b - 9.4bcde - 9.6cde        - 177.6a - 

PB15 86.8abcd - 102.64c - 25.9ab - 9cde - 9.2de          - 166abcd - 

PD14 85.8bcd 91.8d 102.56c 96.6a 25.28b 23.7ab 10.6bcd 11.4a 11abcd    11.4ab 178.4a 52.4ab 

PD15 87.4abcd 92.8cd 104.54c 97.32a 24.66b 22.6ab 9.6bcde 8b 11abcd    8.4b 157.2cd 49.8ab 

PDB3 87.4abcd 92.8 104.06c 100.6a 24.88b 24.1a 11.2abc 10ab 13ab        10ab 153.4d 48.2ab 

PBD1 87.6abc 94bc 104.72c 100.5a 24.9b 22.1bc 11abc 11.6a 12.4abc   11.6a 170.6abc 45.4b 

PBD3 88ab 94bc 99.9c 96.22a 22.86c 23.3ab 12ab 11.6ab 13.2ab     10.6ab 168.4abc 59.4a 

DPB7 85.2d 91.8d 113.44a 102.1a 25.04b 24a 9.4bcde 11.8a 9.8cde     11.8a 161.4bcd 53.4ab 

DPB12 86bcd 92.8cd 106.1bc 99.68a 25.04b 23.4ab 7.2e 9.2ab 7.8e         9.4ab 152.4d 52.2ab 

DPB13 86.2bcd 93cd 103.6c 98.44a 25.18b 23.4ab 9.4bcde 10.2ab 9.6cde     11.4ab 161bcd 43.76b 

DPB20 85.6cd 95b 112.3ab 96.3a 26.58a 23.7ab 9cde 10.2ab 9.2de       10.4ab 165.8abd 46.2b 

LSD 2.25 1.56 6.29 11.82 1.3 1.74 2.92 3.33 2.93         3.07 13.78 11.83 

CV 2.03 1.3 4.74 9.35 4.07 5.87 23.13 25.43 21.69       22.86 6.54 19.34 

Mean 87.03 93.46 104.67 98.54 25.09 23.09 9.96 10.2 10.64       10.46 166.13 47.72 
Std Dev. 
h2 B (%) 

1.93 
16.09 

1.79 
56.18 

5.95 
28.63 

8.51 
-17.54 

1.20 
31.13 

1.55 
28.40 

2.59 
24.03 

2.65 
2.18 

2.74         2.43 
30.24       -0.93 

12.89 
27.06 

11.85 
41.43 

Heritability percentage categorised as low (0-30%), moderate (30-60%), and high (≥60%)  



12 
 

Table 5. Continued 

VARIETIES 
100GW(g) 
NS    RS 

GLW(cm)          
NS      RS 

YM(days)        
NS        RS 

PUTRA1 2.41de - 4.97bc - 117.4ab - 

DROUGHT 2.47cde - 4.98b - 117.4ab - 

IRBB60 2.35e 2.43a 5.61a 4.42a 116.8b 133.2a  

PB12 2.55abc - 4.96bc - 118.2a - 

PB15 2.49cde - 4.81bcd - 117.6ab - 

PD14 2.55abc 2.34a 4.86bcd 4.49a 117.4ab 128.4b 

PD15  2.52abcd 2.4a 4.86bcd 4.49a 117.6ab 127.6b 

PDB3  2.47cde 2.38a 4.53d 4.5a 117ab 127.8b 

PBD1 2.63a 2.42a 4.59bcd 4.51a 117.6ab 127.8b 

PBD3  2.52abcd 2.38a 4.63bcd 4.47a 117.6ab 129b 

DPB7  2.52abcd 2.32a 4.51cd 4.57ab 117ab 127.4b 

DPB12 2.52abcd 2.35a 4.57cd 4.75a 117.6ab 128.2b 

DPB13 2.6ab 2.39a 4.51d 4.57ab 117ab 128.2b 

DPB20   2.56abc 2.43a 4.08e 4.53 117.8ab 127.6b 

LSD 0.12 0.11 0.4 0.2 1.31 1.8 

CV 3.83 3.75 6.63 3.5 0.88 1.09 

Mean 2.51 2.39 4.75 4.53 117.43 128.52 
Std Dev. 
h2 B (%) 

0.11 
16.67 

0.09 
0.5 

0.44 
50.50 

0.17 
6.25 

1.02 
-7.27 

2.05 
56.22 

Var. (variety), IRBB60 (B) (Bacteria leaf blight resistance), Drought (D) (MR219 Drought tolerance),  
reciprocal cross with MR219 Drought, Putra 1 and IRBB60 (DPB), Putra1, IRBB60 and MR219 Drought 
tolerance (PBD), Putra1, MR219 Drought tolerance and IRBB60 (PDB), Putra1 and MR219 drought 
tolerance (PD), Putra1 and IRBB60 (PB), LSD(Least significant difference), CV(Coefficient of variation), 
Mean(average), DF(Days to 50% flowering), HP(cm)(Height of plant  measured in centimeters), 
PL(Panicle length in centimeters)ET(Effective tillers), Tillers (Total number of tillers), FFG(Fully filled 
grains), 100-GWT(100 grain weight in grams), YM (yield maturity counted on number of days from 
sowing to physiological maturity). 

 
Agro-morphological and yield traits data for single cross (F4), double cross (F3(2)), and three-
way cross (F3) for non-drought stress. 

Some parameters of pure-line agro-morphological and yield traits were observed and 
measured to ascertain the differences between the various rice lines and the parent plants. 
Table 3. shows an analysis of variance (ANOVA) of 9 traits, the varieties were all significant 
with the exception of effective tillers (ET). Days to 50% flowering (DF), panicle length (PL) and 
yield maturity (YM) were significant at 5% level of probability (P≤0.05), while height of plant 
(HP), tillers (T), fully filled grain (FFG), 100GW, grain length and width ratio (GLW) were 
significant at 1% level of probability (P≤0.01). No significant differences among the 
replications were recorded in all the morphological and yield traits under non drought stress. 
 
Comparison of parameters of non-drought stress (NS) and reproductive drought stress (RS). 

Table 4. and Table 5. compares nine (9) mean data of the two treatments of non-
drought stress (NS) and reproductive drought stress (RS). The comparison was between 
improved lines from the three crossed methods. Even though there were 14 lines in all on NS 
and 10 on RS because, non drought stress had the three (3) parent plants and  two (2) single 
cross lines PB12, PB15 which did not have drought tolerance QTLs to be subjected in to 



International Journal of Applied Biology, 3(2), 2019 

                                                    
 
 

         13 
 

reproductive drought stress treatment. Now, the parameters of days to 50% flowering (DF), 
height of plants (HP), fully filled grain (FFG), yield maturity (YM) showed that the means of 
reproductive drought stress (RS) was higher on all the improved lines and each compared to 
their non-drought stress lines. While days to 50 % flowering on NS has the highest and lowest 
number of days as 89 and 86 days respectively. RS had 91.8 and 96 days for lowest and highest 
respectively. Height of plants (HP) for NS measured 102.3-112.3 cm and RS 96.3-102.1 cm for 
lowest and highest respectively. The length of panicle for NS was 22.86 cm-26.5 cm and RS 
was 22.6 cm-24.1 cm for lowest and highest respectively. There was an exceptional difference 
between the line PBD3, which showed that the RS measured 23.2 cm in length whereas the 
NS was 22.86 cm in length. The mean number of fully filled grain on NS lines had lowest mean 
as 152.2 and highest 178, and RS was 43.7 and 59.4 for lowest and highest count respectively. 
The parameter of 100-grains weigh measurement taken indicated that the lowest weight for 
NS was 2.52g and the highest weight was 2.63g, for the RS it was 2.32-2.43g, lowest and 
highest respectively. There were slight variations between the two treatments among some 
lines on the parameters of grain length and weight ratio. Even though, the NS ratio was higher 
than RS on five (5) improved lines, four (4) of the RS and reciprocal lines of DPB7, DPB12, 
DPB13, DPB20 were higher than their counterpart lines. Effective tillers (ET) and number of 
tiller (T) didn’t show any clear difference between the two treatments. It was reported that 
water deficit stress affect these quantitative traits which was also confirmed in this study 
(Latiffe et al., 2004; Atlin et al., 2006; Barnabas et al., 2008; Garrity and O’Toole, 1994). There 
were alternating variation among them. This was because the treatment for drought was at 
the reproductive stage when the tillers were matured and could not be affected by just about 
two weeks of water deficit stress. Record has it that drought affect tillers at vegetative stage 
(Cruz et al., 1986). 

In consideration of non drought stress (NS) in the Table 4. and Table 5. with 14 lines 
(parental and improved lines), it indicated the mean days to 50% flowering of Putra1 was 89 
days. This was also corroborated with the findings of Miah et al. (2015) on the same trait of 
the same variety (Putra 1) and significantly different from other traits, but all other traits were 
not significantly different from each other. DPB7 was significantly different on height of plant, 
while the other 8 traits were not different from each other. They tally with their parent plants, 
which indicated their was no variation. DPB20 and PBD3 were significantly different from each 
other and the other genotypes on parameter of panicle length. The other genotypes including 
the parent plants were not different from each other. All other parameters did not show 
difference between parents and progenies except the parameters of effective tillers, tillers 
and grain length and width ratio showing significant difference between IRBB60 and others, 
although with some similarities with other genotypes. 

Considering the means of reproductive drought stress (RS), it has indicated that the 
improved lines were different from the susceptible (control) variety because, the improved 
lines were introgressed with drought tolerance QTLs (qDTY) which conferred on it ability to 
adjust to some level of water deficit stress as against the control check that had no drought 
tolerance qDTY. Field evaluation of MR219 carrying these three qDTY2.2, qDTY3.2, qDTY12.1, 
confirmed tolerance to reproductive drought stress with grain yield of 756-2521 kg ha-1 for 
2013 and 903-2523 kg ha-1 in the year 2014, while the susceptible variety had grain yield of 
13 kg ha-1 in 2013 and didn’t flower in 2014 (Shamsuddin et al., 2016). Venuprasad et al. 
(2009) and Swamy et al. (2013) reported tolerance ability of qDTY3.1 and qDTY2.2 respectively. 
Mishra et al. (2013) reported that twenty one (21) experiments conducted in eastern India 



International Journal of Applied Biology, 3(2), 2019 

                                                    
 
 

         14 
 

and IRRI confirmed that qDTY12.1 has an effect that increases with increasing severity of water 
deficit stress. These confirms the reason the improved lines performed better compared with 
its susceptible check. 

 
Heritability estimate on non drought stress (NS) and reproductive drought stress (RS) 
treatments. 

Broad sense heritability is the total ratio of genetic variance to phenotypic variance. 
In order words, the proportion of the parental gene inherited in the progenies that are 
influenced by the environment and expressed in the phenotypic traits. The percentage ratio 
is expressed as low, medium and high represented as 0-30%, 30-60% and ≥60% respectively. 

The broad sense heritability of characters studied for non drought stress (NS) and 
reproductive drought stress (RS) treatments (Table 4 and Table 5) were all within the range 
of 0 to 56.22, which was within low to moderate heritability. These indicated the magnitude 
of heritability that was influenced by environmental factors. Low percentage is higher 
environmentally influenced and moderate heritability is lesser. Climatic factors which are 
environmental in nature presents a great challenge to rice plant, there are various optimum 
temperature requirements for various growth phases and stages, outside the range it affects 
that phase of development (Tashiro and Wardlaw, 1989, Baker and Allen, 1993, Singh et al., 
1996, http:ricepedia.org). Control experiment and field experiment often presents a variation 
in response to environmental factors. For instance, IRRI-SES (2013) categorised scoring and 
protocols for diseases and tolerance evaluation for green or glass house experiment 
differently from field. The low and medium heritability may not present a true genotypic 
content of the improved lines in respect of the treatment since heritability estimate in this 
case is not restrictive and does not consider experimental environment. The varieties used as 
recipient parents were all high yielding, resistant and tolerant. And confirmed to be so 
resistant and tolerant by the genotyped and phenotyped results. 

The magnitude of heritability among the parameters of non drought stress (NS) 
showed that all characters were within the lowest percentage of heritability which suggests 
environmental influence, except days to 50% flowering (DF), fully filled grains (FFG) and yield 
maturity (YM) which were medium ranged as; 56.18%, 41.43% and 56.22% respectively. 
Reproductive drought stage (RS) treatment showed characters that were also low ranged with 
exception of traits of panicle length 31.13%, tillers (T), 30.24% and grain length and width 
ratio (GLW), 50.50% as medium heritability, indicated as having lesser environmental 
influence compared to low heritability. All ranges of heritability percentage estimates were 
also reported by Oladosu et al. (2014), Meena et al. (2016), Ridzuan et al. (2018). The low 
heritability may not present the true nature of the inherited genes, because controlled 
environment of research may present a variation different than when in a field environment. 

 
 
 
 
 
 
 
 



International Journal of Applied Biology, 3(2), 2019 

                                                               15 
 

Table 6. Estimates of correlation coefficients on the phenotype among 9 traits in rice lines for non drought stress 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

∗Significant at P≤ 0.05, ∗∗highly significant at P≤ 0.01, ns: non-significant P> 0.0

 DF(no) HP(cm) PL(cm) ET(no) T(no) FFG(no) 100GW(g) GLW(cm) YM(days) 

DF(N0) 1         

HP(cm) -0.26246* 1        

PL(cm) -0.2019 0.30623** 1       

ET(no) 0.00606 -0.07271 -0.11752 1      

T(no) 0.00196 -0.12024 -0.24529* 0.92492** 1     

FFG(no) 0.00394 -0.13601 0.06923 0.08221 -0.00771 1    

100GW(g) -0.2765* 0.07116 0.06867 0.01494 -0.03721 0.13656 1   

GLW(cm) 0.34151** -0.26206* -0.11788 0.01078 0.00824 0.09208 -0.29898 1  

YM(days) -0.01376 0.1382 0.05447 0.11179 0.04018 0.23267 0.17624 -0.12587 1 



16 
 

Correlation coefficient relationship for non-drought stress 
The r-values and test of significance provided by proc corr in SAS program (Table 6) 

showed days to 50% flowering (DF) and height of plant (HP), 100-grain weight were 
significantly different (P≤0.05), while with grain length and width ratio showed high significant 
difference (P≤0.01). All the traits were low and negatively correlated. Height of plant (HP) 
with panicle length (PL) and grain length and width ratio (GLW) were significant at (P≤0.05) 
and (P≤0.01) respectively. Both were similarly low and negatively correlated. Panicle length 
(PL) and effective tillers (ET) were jointly significant to tillers (T) at (P≤0.05) and (P≤0.01). while 
the former is low and negatively correlated, the later is high and positively correlated. Notable 
high correlated relationship was observed between height of plant (HP), effective tillers and 
100GW. The relationship with ET though both were high but it was strongly negative, while 
with 100GW was strong positive linear relationship. Ridzuan et al. (2019) and Oladosu et al. 
(2018) also used phenotypic traits to determine relationships. 

Karl Pearson’s correlation coefficient r-value helps to identify association that exists 
between two unique traits, even though it is not able to measure the magnitude (extent) of 
association but gives a clue as to the relationship. The interpretation of correlation coefficient 
was given, but Ratner (2009) provides an accepted standard guideline.  

The r-value could indicate no linear relationship, positive linear relationship and 
negatively linear relationship represented by 0, +1, and -1 respectively. Low, moderate and 
strong positive linear relationships are represented with values ranging from 0-0.3, 0.3-0.7 
and 0.7-1, respectively while 0 to -0.3, -0.3 to -0.7, and -0.7 to -1 would indicate low, moderate 
and strong negative linear relationship respectively. 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 



International Journal of Applied Biology, 3(2), 2019 

                                                               17 
 

Table 7. ANOVA for the parameters showing level of significance for reproductive stage drought stress (RS) 

 
 
 
 
 
 
 
 
 
 

∗Significant at p ≤ 0.05, ∗∗highly significant at p ≤ 0.01, ns: non-significant p > 0.05, DF. (degree of freedom), REP.(Replications),  
Cor. Total (Corrected total), DF(Days to 50% flowering), HP(cm)(Height of plant  measured in centimetres), PL(Panicle length in centimetres),      
ET(Effective tillers),Tillers (total number of tillers), FFG(Fully filled grains), 100-GW(100 grain weight in grams) 

Source       DF DF(day) HP(cm) PL(cm) ET(no)   T(no) FFG(no) 100GW(g) GLW(cm) YM(days) 

Var 9 11.02** 21.53ns 5.47** 7.47ns 6.22ns 384.90** 0.01ns 0.04ns 14.63** 

Rep. 4 0.93ns 74.74ns 0.62ns 8.65ns 7.13ns 86.59ns 0.01ns 0.02ns 0.97ns 

Error 36 1.49ns 84.94ns 1.84ns 6.73ns 5.72ns 84.83ns 0.01ns 0.03ns 1.97ns 

Cor. Total 49          



18 
 

Table 8. Estimates of correlation coefficients on the phenotype among 9 traits in rice varieties for reproductive drought stress 

 
 
 
 
 
 
 
 
 
 
 
 
 

 DF(days) HP(cm) PL(cm) ET(no) T(no) FFG(no) 100GW(g) GLW(cm) YM(days) 

DF(days) 1         

HP(cm) -0.11295 1        

PL(cm) -0.34917* 0.04025 1       

ET(no) -0.1276 0.02553 0.06464 1      

T(no) -0.11063 0.02957 0.05282 0.98204** 1     

FFG(no) -0.35762* -0.06439 0.24756 0.1528 0.1108 1    

100GW(g) 0.26915 -0.0041 -0.18723 -0.13435 -0.13343 -0.11789 1   

GLW(cm) -0.21732 0.08631 0.17222 0.07339 0.0711 0.2032 -0.00037 1  

YM(days) 
0.59004** -0.11094 -0.53245** -0.0833 -0.06109 -0.4332* 0.13789 -0.22637 1 



19 
 

ANOVA for Agro-morphological and yield traits data for single cross (F4) double cross F3(2), 
and three-way cross and reciprocal (F3) under reproductive drought stress (RS). 

Phenotyping for reproductive drought tolerance was carried out to determine the 
level of improved lines tolerance to water deficit condition. This is very importance due to 
challenges of climate change and irregular rainfall for rainfed rice and also for irregular 
irrigation water supply. The ANOVA Table 7. showed highly significance difference (P≤0.01) 
among varieties (improved lines) on the parameters for DF, PL, FFG, YM, while there was non 
among the replicates. This clearly indicated the effect of drought on these very important 
parameters (quantitative traits) whose effect affect yield drastically (Taglea et al., 2016, 
Chang et al., 2016). 

 
Correlation coefficient relationship for non-drought stress 

In Table 8 which estimated the relationship among phenotypes of the reproductive 
drought stress traits indicated that days to 50% flowering (DF) had a significant relationship 
with panicle length (PL) and fully filled grain (FFG) at (P≤ 0.05) although negative and moderate 
but yield maturity (YM) at (P≤0.01), it was positive and moderate correlated relationship. 
Panicle length (PL) and yield maturity (YM), effective tillers (ET) and fully filled grain (FFG) 
were both significant at P≤0.01. while the former is negative and moderately correlated the 
later was low but positively correlated.  

The strongest positively and high correlated relationship but not significant was 
between effective tillers (ET) and total number of tillers per plant  (T). It is because most of 
the tillers were effective despite the drought stress. Stress was introduced at the 
reproductive stage when tillers were already matured and it could not affect it. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 



International Journal of Applied Biology, 3(2), 2019 

                                                               20 
 

Table 9. ANOVA for the parameters showing Interaction levels of significance 

 
 
 
 
 
 
 
 
 
 

 
∗Significant at p ≤ 0.05, ∗∗highly significant at p ≤ 0.01, ns: non-significant p > 0.05, DF. (degree of freedom), REP.(Replications), Cor.. Total (Corrected total), 

DF(Days to 50% flowering), HP(cm)(Height of plant measured in centimetres), PL(Panicle length in centimetres), ET (Effective tillers),Tillers (total number of 

tillers), FFG(Fully filled grains), 100-GW(100 grain weight in grams), YM (yield maturity counted on number of days from sowing to physiological maturity). 

 
 
 
 
 
 
 
 
 

SOV DF DF(days) HP(cm) PL(cm) ET(no) T(no) FFG(no) 100GW(g) GLW(cm) YM(days) 

Treatment 1 1020.17*
* 

1091.15*
* 

69.17** 7.04ns 0.02ns 325366.67*
* 

0.60** 0.18ns 2733.4** 

Varieties 10 6.22* 67.75ns 3.70** 10.30* 11.87*
* 

307.53** 0.01ns 0.19** 1.09ns 

Replications 4 0.89ns 89.62ns 1.89ns 10.26ns 8.51ns 165.90ns 0.01ns 0.08ns 1.92ns 

Trt*Var 8 3.6ns 42.50ns 2.59* 5.43 10.66* 211.25* 0.01ns 0.17* 0.75ns 

Error 
Total 

76 
99 

2.52 53.68 1.13 4.33 4.40 90.70 0.01 0.06 1.25 



International Journal of Applied Biology, 3(2), 2019 

                                                               21 
 

Table 10. Correlation coefficient of interaction of non drought stress (NS) and reproductive drought stress (RS) treatments. 

 DF(days) HP(cm) PL(cm) ET(no) T(no) FFG(no) 100GW(g) GLW(cm) YM(days) 

DF(days) 1         

HP(cm) -0.43695** 1        

PL(cm) -0.5883** 0.39373** 1       

ET(no) 0.12171ns -0.00503ns -0.22585* 1      

T(no) 0.02853ns -0.00643ns -0.23369* 0.92342** 1     

FFG(no) -0.87446** 0.37901** 0.55552** -0.09132ns 0.0005ns 1    

100GW(g) -0.60745** 0.30235** 0.35449** -0.1395ns -0.0953ns 0.68357** 1   

GLW(cm) -0.00568ns -0.05578ns -0.02718ns 0.10715ns 0.11803ns 0.15551ns 0.11917ns 1  

YM(days) 0.87083** -0.41243** -0.56762** 0.13997ns 0.01887ns -0.95227** -0.64997** -0.14577ns 1 

∗Significant at p ≤ 0.05, ∗∗highly significant at p ≤ 0.01, ns: non-significant  p ≤ 0.05, DF. (degree of freedom), REP.(Replications), Cor..Total (Corrected total), 
DF(Days to 50% flowering), HP(cm)(Height of plant measured in centimeters), PL(Panicle length in centimeters), ET(Effective tillers),Tillers (total number of 
tillers), FFG(Fully filled grains), 100-GW(100 grain weight in grams), YM (yield maturity counted on number of days from sowing to physiological maturity). 
  



International Journal of Applied Biology, 3(2), 2019 

                                                    
 
 

         22 
 

Interactions of reproductive drought stress (RS) and non drought stress (NS). 

There were interactions between treatment and varieties (TRT*VAR.) in Table 
9. Panicle length (PL), Tillers (T), Fully filled grain (FFG) and Grain length and width 
ratio (GLW) interacted at P≤0.05. while the other parameters were not significant. The 
significant interactions was because of the variation in treatments (reproductive 
drought stress (RS) and non drought stress (NS)) while the varieties comprised of data 
from the improved lines (progenies) subjected to stress and non stress conditions. 
Shortage of water was responsible because of its dire need for living cells functioning 
and turgidity (Sukhla, 2012). The parameters affected are yield borne especially fully 
filled grains (FFG). Juraimi et al. (2009), Sikuku et al. (2009), Masitah, (2018) reported 
that days to flowering, yield maturity, fully filled grain, panicle length are affected by 
drought stress. Variation of significance on major yield component was also attributed 
to biochemical, physiological, morphological and anatomical effect of water deficit 
condition (Serraj et al., 2009).  

Reproductive stage of rice is a very sensitive stage and responded to drought 
stress in affecting flowering and heading as also confirmed by Davatgar et al. (2009). 
drought stress often results in low tissue water potential for rice (Sikuku et al., 2010). 
Generally, low yield underscore the importance of water (Juraimi et al., 2009). 

 
Correlation coefficient of interaction 

The interaction correlation coefficient Table 10. showed highly significant 
interaction between days to 50% flowering (DF) with height of plant (HP), panicle 
length (PL), fully filled grain (FFG), 100 grain weight (100GW) and yield maturity (YM). 
All correlation coefficient relationships were either negatively medium or high, with 
the exception of yield maturity which was both strong and positively correlated 
relationship. This clearly indicated the influence of days to 50% flowering to yield 
maturity due basically to water stress treatment which delayed maturity because of 
distortion of the normal physiological and biochemical processes of the rice plant 
(Serraj, 2009; Juraimi, et al., 2009). For height of plant (HP), there were highly 
significant (P≤0.01), negatively medium correlation relationship with panicle length 
(PL), effective tillers (ET), 100grain weight (100GW) and yield maturity (YM). the 
relationship between effective tillers (ET) and tillers (T) was significant P≤0.01 but with 
strong negative correlation. Fully filled grains (FFG) was also highly significant (P≤0.01) 
with 100 grain weight (100GW) and yield maturity (YM) at medium and strongly 
negative correlated relationship respectively. The parameter of 100 grain weight 
(100GW) was highly significant (P≤0.01), medium and negatively correlated. 

 
Clustering and principal component analysis 

The analysis of genetic variability is one important criterion for parental 
selection by the estimate of the extend of variation that existed among the genotypes. 
The specific information on the nature and degree of genetic variability is critical for 
selection of ideal parent so as to minimize the number of crosses that would have 
been required. (Guerra et al., 1999, Yatung et al., 2014). 

 



International Journal of Applied Biology, 3(2), 2019 

                                                    
 
 

         23 
 

Non drought stress 
The study considered 14 genotypes which comprised of the 3 parents and their 

progenies (improved lines). They were clustered into four main groups based on their 
quantitative characteristics at genetic similarity of 0.122 in order of distance to the 
various genotypes in the population. Clustering of 39 genotypes according to 
morphological characteristics majorly on the size of fruit was reported by Geleta et al., 
2005. The genetic distance dendrogram was constructed in accordance to the UPGMA 
method using NTSYS-pc version 2.1. The Figure 7. showed the clustered genotypes 
into four groups.  

Groups III and IV comprised of two genotypes each namely DPB7, DPB20 and 
PB15, PBD3 respectively. Group I and II comprised of 6 and 4 genotypes respectively. 
While Putra 1, IRBB60, PBD1, Drought (MR219 drought tolerance), PB12,PD14 were 
clustered in group I, PD15, PBD3, DPB13 and DPB12 were clustered in group II. There 
parental plants and were clustered along with the first two crossed generations that 
produced the three-way and double crosses. 

The PCA results are indicated in Figure 8. the farthest genotypes from the 
centroid were PBD3. PB15, PD14, PB12, DPB7, DPB12, while the closest to the 
centroid were DPB13, PD15, PDB3. three genotypes were intermediary between the 
farthest and closest, which included; PUTRA1, IRBB60 and PBD1.



International Journal of Applied Biology, 3(2), 2019 

                                                               24 
 

 
 
 

 

Figure 7. Clustering pattern of the agro-morphological and yield based on 14 trait at dissimilarity coefficient of 0.122 

Coefficient

0.050.230.410.590.77

DROUGHT

 PUTRA1 

 IRBB60 

 PBD1 

 DROUGHT 

 PB12 

 PD14 

 PD15 

 PDB3 

 DPB13 

 DPB12 

 DPB7 

 DPB20 

 PB15 

 PBD3 

Group I 

Group IV 

Group III 

Group 

II 

0.122 



25 
 

 

 

 
Figure 8. Principal component analysis (PCA) of relationship among fourteen (14) rice lines in a 2-dimentional graph 

 
 
 
 

PC1 

PC2 



26 
 

Reproductive drought stress 
In this study, 10 genotypes (lines) were clustered together into six groups based on 

nine quantitative traits at the reproductive stage drought stress (RS) to separate different 
genotypes in the population. UPGMA method using NTSYS-pv v2.1 was similarly used to 
construct the genetic distance dendrogram. The genotypes here were clustered into 6-group 
at 0.094 genetic similarity as shown in Figure 9. 

Group I, III, IV and VI  comprised of only one line (genotype) each such as CONTROL, 
DPB7, PDB3 and PBD3 respectively. While group II and V each comprised of three genotypes; 
PD14, PD15, DPB12 and PBD1, DPB13, DPB20 genotypes respectively.  

Figure 10. showed the result of PCA. The genotypes distanced away from the centroid 
in the order of distance comprised of CONTROL, PBD3, DPB7, and three genotypes were 
intermediary such as PBD1, DPB20, PD14, while the others were closest to the centroid, and 
they included PD15, DPB13, DPB12 and PDB3. Group I stood out as the lowest with yield since 
it was the control and was susceptible to RS. 

Table 11. Grouping of 14 and 10 improved and selected lines for non drought stress (NS) 
and reproductive drought stress (RS) respectively for cluster analysis 

Treatment Cluster 
number 

Number of 
genotypes 

Genotypes 

NS I 6 PUTRA1, IRBB60, PBD1, DROUGHT, PB12, PD14 

 II 4 PD15, PDB3, DPB13, DPB12 

 III 2 DPB7, DPB20 

 IV 2 PB15, PBD3 

RS I 1 CONTROL 

II 3 PD14, PD15, DPB12 

III 1 DPB7 

IV 1 PDB3 

V 3 PBD1, DPB13, DPB20 

VI 1 PBD3 



International Journal of Applied Biology, 3(2), 2019 

                                                               27 
 

 

Figure 9. Relationship among the 10 developed and selected lines (genotypes) based on 9 characteristics (traits) using     

SAHN clustering of UPGMA method 

 

 

 

Coefficient

0.050.160.260.360.47

CONTROL

 CONTROL 

 PD14 

 PD15 

 DPB12 

 DPB7 

 PDB3 

 PBD1 

 DPB13 

 DPB20 

 PBD3 

0.094 

Group I 

Group IV 

Group V 

Group VI 

Group II 

Group III 

 



International Journal of Applied Biology, 3(2), 2019 

                                                               28 
 

 

 

 

 

Figure 10. Principal component analysis of relationship amongst 10 improved lines and selected lines in two dimensional graph

PC1 

PC2 

 



29 
 

Conclusion 
The two recipient parents (Putra1 and MR219 drought tolerant) used in the different 

crossing methods were high yielding, resistant and tolerant to blast (Magnaporthe grisea) 
and drought respectively. And a donor IRBB60 resistant to bacteria leaf blight (Xanthomonas 
oryzae). The yield parameters showed that there was no yield loss on non-drought stress 
treatment on improved lines except on reproductive drought stress treatment. The 
interactions showed that reproductive drought stress affected days to flowering, fully filled 
grain and yield maturity significantly. The profitability of these parameters are often 
dependent on the reproductive stage, but shortage of water tempered with their due 
performances. Even though there was reduction in yield, but it was still within average yield 
performance of drought tolerant variety due to the presence of introgressed genes/QTLs 
compared with the susceptible variety in reproductive drought stress (RS) treatment. 

Prior knowledge of the rice genotype is important in making informed decision on 
selection of the best cultivars for variety improvement. Genetic variation is an indication of 
the possibility of diverse source of origin and the result gave a clue as to the genetic/QTL 
variance of the rice populations.  

In consideration of the variation pattern and other agro-morphological and yield 
performance, the improved and selected lines PB12, PBD1, and PD14 in group I, PDB3 in group 
II, DPB20 in group III and PB15, PBD3 in group IV could be considered as better lines on good 
yield under non drought stress (NS) treatment. In reproductive drought stress (RS) treatment, 
PD14, DPB12 in group II, DPB7 in group III and PDB3in group IV. While in groups V and VI were 
PBD1, DPB20 and PBD3 respectively. Generally, the yield performances of the different lines 
for both NS and RS were all within considerable high yielding range, with high potentials for 
increased yield with different environmental trials since the QTLs could be influenced by 
different environments, even though the recommended ones were better. 

 

References 
Abenavoli, M. R., Leone, M., Sunseri, F., Bacchi, M & Sorgona, A. 2016. Root phenotyping for 

 drought tolerance in bean landraces from Calabria (Italy). J Agron Crop Sci, 
 202(1),1–12. 

Alonso-Blanco, C., Aarts, M. G. M., Bentsink, L., Keurentjes, J. J. B., Reymond, M., 
 Vreugdenhil, D. & Koornneef, M. 2009. What has natural variation taught us about 
 plant development, physiology, and adaptation? Plant Cell, 21(7), 1877–1896. 

Amante-Bordeos, A., Sitch, L., Nelson, R., Dalmacio, R., Oliva, N., Aswidinnoor, H & Leung, H 
(1992) Transfer of bacterial blight and blast resistance from the tetraploid wild rice 
Oryza minuta to cultivated rice, Oryza sativa. Theor Appl Genet 84:345–354 

Anower, M. R., Boe, A., Auger, D., Mott, I. W., Peel, M. D., Xu, L., Kanchupati, P. & Wu, Y. J. 
2015. Comparative drought response in eleven diverse Alfalfa accessions. J Agron  
Crop Sci, 203: 1–13. 

Asghar, A. H., Rashid, M., Ashraf, M. Khan, H. & Chaudhry. A.Z. 2007. Improvement of basmati 
rice, against fungal infection through gene transfer technology. Pak. J. Bot. 
 39(4), 1277-83. 

Ashkani, S, Rafii, M.Y,  Sariah, M., Abdullah, S.N.A, Rusli, I., Harun A.R & Latif, M.A. 2011. 
 Analysis f Simple Sequence Repeat Markers Linked with Blast Disease Resistance 
 Genes in A Segregating Population of Rice (Oryza sativa). Genet Mol Res  10:1345–
1355. 



International Journal of Applied Biology, 3(2), 2019 

                                                    
 
 

         30 
 

Atlin, G.N., Lafitte, H.R., Tao, D., Laza, M., Amante, M. & Courtois, B. 2006. Developing rice 
 cultivars for high fertility upland systems in the Asian Tropics. Field Crops 
 Res.;97:43–52. 
Baker, J.T & Allen, Jr. L.H. 1993. Contrasting crop species responses to CO2 and temperature: 
 rice, soybean and citrus. Vegetation 104/105: 239-260.  
Banito, A., Kadai, E.A. & Sere, Y. 2012. Screening of rice varieties for resistance  to bacteria 
 leaf blight. Journal of applied Biosciences. 53:3742-3748 
Barnabas, B., Jager, K. & Feher, A. 2008. The effect of drought and heat stress on reproductive 

processes in cereals. Plant Cell Environ.;31:11–38. 
Boonjung, H & Fukai, S. 1996. Effects of soil water deficit at different growth stages on rice 

 growth and yield under upland conditions. 2. Phenology, biomass production and 
 yield. Field Crops Res. 48, 47–55. 

Bouman, B.A.M., Lampayan, R.M & Tuong, T.P. 2007. Water management in irrigated rice: 
coping with water scarcity. Los Baños (Philippines): International Rice Research   
Institute, 54 pp 

Bray, E. A., Bailey-Serres, J. & Weretilnyk, E. 2000. Responses to abiotic stresses. In: Gruissem 
W, Buchannan B, Jones R. Biochemistry and Molecular Biology of Plants. Maryland, 
USA: American Society of Plant Physiologists: 1158–1249. 

Castano, J.B., Amril, B, Syahril, D. & Zaini, Z. 1990. Upland rice genotypes resistant to blast 
(B1) disease in west Sumatra. Int. Rice Res. Newslet. 15(4),11-2. 

Chang, S., Chang, T., Song, Q., Zhu, X-G. & Deng, Q. 2016. Photosynthetic and agronomic traits 
of an elite hybrid riceY-Liang-You 900 with a record-high yield. Field Crops 
 Research 187:49–57 http://dx.doi.org/10.1016/j.fcr.2015.10.011  

Cruz, R.T., O’Toole, J.C., Dingkuhn, M., Yambao, E.B., Thangaraj, M. & DeDatta, S.K. 1986. 
Shoot and root responses to water deficit in rainfed rice. Aust. J. Plant Physiol. 13, 
567–575. 

Davatgar, N., Weishabouri, M.R., Paskhah, A.R & Soltani, A. 2009. Physiological and 
 morphological responses of rice (Oryza sativa L.) to varying water stress 
 management strategies. International Journal of plant productivity, 3,19-32 

Doyle, J.J., & Doyle, J.L. 1987. A rapid DNA isolation procedure for small quantities of fresh 
leaf tissue. Phyt Bull 19:11-15. Article PubMed/NCBI Google scholar 

Garrity, D.P. & O’Toole, J.C. 1994. Screening Rice for Drought Resistance at the Reproductive 
Phase. Field Crop. Res. 39:99-110. 

Geleta, L.F., Labuschagne, M.T. & Viljoen, C.D. 2005. Genetic variability in pepper (Capsicum 
 annuum L.) estimated by morphological data and amplified fragment length 
 polymorphism markers. BiodiversConserv 14, 2361–2375.  

Google: https://archive.gramene.org/markers/ (retrieved 7th August, 2019) 
Google: http://ricepedia.org/rice-as-a-plant/growth-phases(Retrieved 03-08-2019) 
Guerra, E.P., Destro, D., Miranda, L.A & Montalvan, R. 1999. Parent selection for intercrossing 

in food types soybean through multivariate genetic divergence. Acta scientiarum 
 Agronomy, 21(3), 429-437 

Guo, L. B., Luo L. J., Xing, Y. Z., Xu, C. G., Mei, H. W., Wang, Y. P., Zhong, D. B., Qian, Q., 
 Ying, C. S. & Shi, C. H. 2003. Dissection of QTLs in two years for important  agronomic 
traits in rice(Oryza sativa L.). Chinese Journal of Rice Science, 17, 211- 218. (in Chinese) 

https://archive.gramene.org/markers/
http://ricepedia.org/rice-as-a-plant/growth-phases


International Journal of Applied Biology, 3(2), 2019 

                                                    
 
 

         31 
 

Han, L.Z., Qiao, Y., Zhang, S.Y., Cao, G.L., Ye, C.R., Xu, F.R., Dai, L., Ye, J.D. & Koh, H.J. 
 2006. QTL Analysis of Some Agronomic Traits in Rice Under Different Growing 
 Environments. Agricultural Sciences in China. 5(1), 15-22 

Han, L. Z.,Yuan, D. L., Xuan, Y. S., Piao, Z. Z. & Koh, H. J. 2004. Genetic analysis of cold 
 water response on several agronomic traits of rice. Chinese Journal of Rice Science, 18, 
23-28. (in Chinese) 

Haq, I. M., Fadnan, M., Jamil, F.F. & Rehman, A. 2002. Screening of rice germplasm against 
Pyricularia oryzae and evaluation of various fungitoxicants for control of disease. 
 Pak. J. Pythopath. 14(1), 32-5. 

He Q, Li D, Zhu Y, Tan M, Zhang D, Lin X (2006) Fine Mapping of Xa2, a Bacterial Blight
 Resistance Gene in Rice. Mol Breeding 17:1–6. 

Iqbal, M., Khan, M.A., Naeem, M., Aziz, U., Afzal, J. & Latif, M. 2013. Inducing drought 
 tolerance in upland cotton (Gossypium hirsutum L.), accomplishments and future 
prospects. World Applied Science Journal 21, 1062–1069. 

IRRI International rice research institute, Standard Evaluation System (SES) for Rice (2013). 5th 
ed. Manila, Philippines 

Jena, K. K. & Mackill, D. J. 2008. Molecular markers and their use in marker-assisted selection 
 in rice. Crop Sci, 48(4), 1266–1276. 

Jia,Y., Me, S.A., Adams, G.T., Bryan, H. Hershay, P. & Valent, B. 2000. Direct interaction of 
resistance genes products confers rice blast resistance Embo. J., 19, 4004-4014. 

Juraimi, A.S., Najib, M.Y.M., Begum, M., Anuar, A.R., Azmi,M. & Puteh, A. 2009. Critical 
 period of weed competition in direct seeded rice under saturated and flooded 
 conditions. Pertanika Journal of Tropical Agricultural Science 32, 305-316  

Kadioglu A & Terzi R. 2007. A dehydration avoidance mechanism: Leaf rolling. Bot Rev,  
73(4):290–302. 

Khan, J. A., Jamil, F. F.,  Cheema, A.A. & Gill, M. A. 2001. Screening of rice germplasm 
 against blast disease caused by Pyricularia oryza In: Proc. National Conf. of Plant 
 Pathology, held at NARC. Islamabad. Oct 1-3. pp. 86-9. 

Khan TH, Evamoni FZ, Rubel MH, Nasiruddin KM, Rahman M (2015) Screening of Rice Varieties 
for Bacterial Leaf Blight Resistance by Using SSR Markers. J Biosci  Agric Res 3:45-58. 

Kumar, A., Dasgupta, P. & Kumar, R. 2014. Emerging opportunities and challenges in rice 
production. Pop Kheti, 2(2), 6–11. 

Kumbhar, S.D., Kulwal, P.L., Patil, J.V., Sarawate, C.D., Gaikwad, A. P. & Jadhav, A.S. 2015. 
Genetic diversity and population structure in landraces and improved rice varieties 
from India. Rice Sci, 22(3), 99–107. 

Latif, M.A., Badsha, M.A., Tajul, M.I., Kabir, M.S., Rafii, M.Y. & Mia, M.A.T. 2011. 
 Identification of genotypes resistant to blast, bacterial leaf blight, sheath blight and 
tungro and efficacy of seed treating fungicides against blast disease of rice. 
 Scientific Research and Essays 6, 2804-2811. 

Lafitte, H.R., Price, A.H. & Courtois, B. 2004. Yield response to water deficit in an upland rice 
 mapping population: associations among traits and genetic markers. Theoretical 
 Applied Genetics 109, 1237–1246. 

Li, Y., Hu, L., Romeis, J., Wang, Y., Han, L., Chen, X. & Peng, Y. 2014. Use of an artificial diet 
system to study the toxicity of gut-active insecticidal compounds on larvae of the 
green lacewing Chrysoperla sinica. Biol Control 69, 45–51. 



International Journal of Applied Biology, 3(2), 2019 

                                                    
 
 

         32 
 

Luo, Y, Tang, P.S., Febellar, N.G. & TeBeest, D.O. 1998. Risk analysis of yield losses caused by 
rice leaf blast associated with temperature changes above and below for five Asian 
countries. Agri. Ecosys. & Environ. 68,197-205.  

Maclean, J.L,, Dawe, D.C., Hardy, B. & Hettel, G.P. 2002 Rice Almanac. 3rd ed. Philippines: 
IRRI, WARDA, CIAT and FAO. 2002. 

Mahdieh S, Hosseini M, Soltani J (2013) An investigation on the effects of photoperiod, aging 
and culture media on vegetative growth and sporulation of rice blast Pyricularia 
 oryzae. Progress in Biological Sciences 3 (2):135-143 

Mashitah, A.B. 2018. Devlopment of weed competitive rice variety under water deficit 
 conditions through marker assisted backcrossbreeding. Thesis, Universiti Putra 
 Malaysia. 

McCouch, S.R., Kochert, G., Yu, Z.H., Wang, Z.Y, & et al. 1988. Molecular mapping of rice 
 chromosomes. Theor. Appl. Genet. 76: 815-829. 

Meena, M.L., Kumar, N., Meena, J.K., & Rai, T, 2016. Genetic variability, heritability and 
 genetic advances in chilli, Capsicum annuum. Biosci Biotechnol Res Commun 
 9:262–266. 

Miah, G., Rafii,M.Y., Ismail,M.R., Puteh, A.B., Rahim, H.A. & Latiff, M.A. 2016. Marker-Assisted 
Introgression of Broad-Spectrum Blast Resistance Genes into the Cultivated MR219 
Rice Variety. J. Sci. Food Agric. Wiley online Library 

Miah, G., Rafii, M.Y., Ismail, M.R., Puteh, A.B., Rahim, H.A. & Latif, M.A. 2015. Recurrent 
 parent genome recovery analysis in a marker-assisted backcrossing program of rice 
(Oryza sativa L.) C. R. Biologies 338, 83–94. 

Mishra, K.K., Vikram, P., Yadaw, R.B., Swamy, B.P.M., Dixit. S., Sta Cruz, M.T., Maturan, P., 
Marker, S. & Kumar, A. 2013. qDTY 12.1: a locus with a consistent effect on grain 
 yield under drought in rice. BMC Genetics 14:12. 

Natrajkumar, P., Sujatha, K., Laha, G.S., Srinivasarao, K., Mishra, B., Viraktamath, B.C., Hari,  
Y., Reddy, C.S., Balachandran, S.M., Ram, T., Sheshumadhav, M., Rani, N.S., 
 Neeraja, C.N., Reddy, G.A., Shaik, H. & Sundaram, R.M. 2012. Identification and 
 fine-mapping of Xa33, a novel gene for resistance to Xanthomonas oryzae pv. 
 oryzae. Phytopathology, 102(2): 222–228. 

Oladosu,Y., Rafii, M.Y., Magaji, U., Abdullah, N., Miah, G., Chukwu, S.C., Hussin, G. & Ramli, 
A., Kareem, I. 2018. Genotypic and Phenotypic Relationship among yield 
 components in rice under tropical conditions. BioMed Research International, 
 Volume 2018, Article ID 8936767, 10 pages. https://doi.org/10.1155/2018/8936767 

Ou, S.H. 1985. Rice Disease (2nd ed.). Commonwealth Mycological Institute, Kew, Surrey, 
England, p. 380. 

Pandey, V. & Shukla, A. 2015. Acclimation and tolerance strategies of rice under drought 
stress.  Rice Sci 22(4), 147–161. 

Pradhan, S.H., Nayak, D.K., Mohanty, S., Behera, M., Barik, S.R., Pandit, E., Lenka, S & 
 Ananda, A. 2015. Pyramiding of Three Bacterial  Blight Resistance Genes for 
 Broad Spectrum Resistance in Deep-Water Rice Variety, Jalmagna 8:19. 

Pinta, W., Toojinda, T., Thummabenjapone, P., Sanitchon, J. (2013). Pyramiding of blast and 
bacterial leaf blight resistance genes into rice cultivar RD6 using marker assisted 
 selection, African Journal of Biotechnology, 12(28):4432-4438 DOI: 
 10.5897/AJB12.2028 

https://doi.org/10.1155/2018/8936767


International Journal of Applied Biology, 3(2), 2019 

                                                    
 
 

         33 
 

Rajashekara, H., Ellur, R.K., Khanna, A., Nagarajan, M., Gopala, K.S., Singh, A.K., Sharma, P., 
Sharma, T.R. & Singh, U.D. 2014. Inheritance of blast resistance and its allelic 
 relationship  with five major R genes in a rice landrace ‘Vanasurya’. Ind 
 Phytopathol, 67(4), 365–369.  

Ratner, B. 2009. “The correlation coefficient: Its values range between +1/−1, or do they?” 
Journal of Targeting, Measurement and Analysis for Marketing 17(2),139–142 

Ribot, C.J., Hirsch, S., Balzergue, D., Tharreau, J.H., Notteghem, M., Lebrun, H. & Morel, J.B. 
2008. Susceptibility of rice to the blast fungus, Magnaporthe grisea. J. Plant 
 Physiol. 165, 114-24. 

Ridzuan, R., Rafii, M.Y., Yusoff, M.M., Ismail, S.I., Miah, G. & Usman, M. (2019). Genetic 
diversity analysis of selected Capsicum annuum genotypes based on 
 morphophysiological, yield characteristics and their biochemical properties J Sci Food 
Agric 99, 269–280 

Saifullah, M. (1995). Comparative efficacy of some new fungicides for the control of rice blast. 
PI. Prot. Bull. Faisalabad. 46(2-3),39. 

Sarkar, R.K., Mahata, K.R. & Singh, D.P. 2013. Differential responses of antioxidant system and 
photosynthetic characteristics in four rice cultivars differing in sensitivity to sodium 
chloride stress. Acta Physiol Plant, 35(10), 2915–2926. 

SAS Institute. SAS⁄Stat user's guide, Version 9.4 SAS Institute, Cary, NC, USA. 2001 
Scardaci, S.C., Webster, R.K., Greer, C.A., Hill, J.E., Williams, J.F., Mutters, R.G., Brandon, D.M., 

McKenzie, K.S. & Oster, J.J. 2003. Rice Blast: A New Disease in California, Agronomy 
Fact, Department of Agronomy and Range Science, University of  California, Davis, 
Sheet Series 1997-2. 

Serraj, R., Kumar, A., McNally, K.L., Slamet-Loedin, I., Bruskiewich, R., Mauleon, R., Cairns, J., 
Hijmans, R.J. 2009. Improvement of drought resistance in rice. Adv Agron, 103: 41–98. 

Shamsudin, N.A., Swamy, B.P.M., Ratnam, W., Cruz, M.T.S., Raman, A. & Kumar, A. 2016. 
Marker assisted pyramiding of drought yield QTLs into a popular Malaysian rice 
 cultivar, MR219. BMC Genetics 17, 30 

Sikuku, P.A., Netondo, G.W., Musyimi, D.M. & Onyango, J.C. 2010. Effects of water deficit on 
days to maturity and yield of three NERICA rainfed rice varieties ARPN Journal of 
Agricultural and Biological sciences, 5,1-9 

Singh, S., Amartalingam, R., Wan Harun, W.S. & Islam, M.T. 1996. Simulated impact of climate 
change on rice production in Peninsular Malaysia. Proceeding of National 
 Conference on Climate Change. UPM, pp. 41-49. 

Sukhla, B. 2012. What is the importance of water for plants? Retrieved from 
 http://www.preservearticles.com/20110101294/importance-of-water-for-
plants.html. Accessed February 26, 2015 

Sundaram, R.M., Chatterjee, S., Olivia, R., Laha, G.S., Cruz, L.J.E. & Sonti, R.V. 2014. Update on 
Bacteria Blight of Rice, Fourth International Conference on Bacterial Blight. 
 Rice 7,12. 

Suresh, S.R., Yenjerappa, S.T., Naik, M.K., Mallesh, S.B., Kalibavi, C.M. 2013. Studies o 
 cultural and  physiological characters of Xanthomonas oryzae pv. oryzae causing 
 bacterial blight of rice. Karnataka J Agric. Sci 26(2):214-216  

http://www.preservearticles.com/20110101294/importance-of-water-for-plants.html
http://www.preservearticles.com/20110101294/importance-of-water-for-plants.html


International Journal of Applied Biology, 3(2), 2019 

                                                    
 
 

         34 
 

Swamy, B.P.M, Ahmed, H.U., Henry, A., et al. 2013. Genetic, physiological, and gene 
 expression analyses reveal that multiple QTL enhance yield of rice mega-variety 
 IR64 under drought. PLoS ONE 8, e62795. 

Tashiro, T. & Wardlaw, I. F. 1989. A comparison of the effect of high temperature on grain 
development in wheat and rice, Annals of Botany 64: 59-65 

Taglea, A.G., Fujitaa, D., Ebrona, L.A., Telebanco-Yanoriaa, M.J., Sasakia, K., Shimarua,T., 
Fukuta, Y. & Kobayashi, N. 2016. Characterization of QTL for unique agronomic 
 traits of new-plant-type rice varieties using introgression lines of IR64. The Crop 
 Journal 4,12-20 

Venuprasad, R., Dalid, C.O., Del Vall,e M., Zhao, D., Espiritu, M., Sta Cruz, M.T., Amante, M., 
Kumar, A. & Atlin, G.N. 2009. Identification and characterization of large-effect 
quantitative trait loci for grain yield under lowland drought stress in rice using bulk-
segregant analysis. Theoretical and Applied Genetics 120, 177–190.  

Yatung, T., Dubey, R.K., Singh, V. & Upadhyay, G. 2014. Genetic diversity of chilli (Capsicum 
annum L.) genotypes of India based on morpho-chemical traits. Australian journal of 
crop science, 8(1),97-102 

Yambao, E.B. & Ingram, K.T. 1988. Drought stress index for rice. Philipp J Crop Sci 
 13(20):105–11. 

Zhang, S.Y., Tan, G.L., Ren, G.M., Li, M.R., Li, Y.Y., Lan, P.X., Gui, F.R., Wang, H.N., Zhu, S.S., Li, 
F. 2015. Investigation of rice virus diseases and analysis of the molecular  variation of 
RSV isolates in the main rice-growing areas of Yunnan Province from 2013 to 2014. 
Chin 

Zhai, W.X. & Zhu, L.H. 1999. Rice bacterial blight resistance genes and their utilization in 
molecular breeding. Advanced BioTech 19, 9-11.