131 J. Hortl. Sci. Vol. 13(2) : 131-136, 2018 Genetic variability, correlation and path analysis in bottle gourd (Lagenaria siceraria (Mol. Standl.) germplasm B. Varalakshmi*, M. Pitchaimuthu and E. Sreenivas Rao Division of Vegetable Crops, ICAR-Indian Institute of Horticultural Research Hesaraghatta Lake Post, Bengaluru - 560 089, India *Email : Varalakshmi.B@icar.gov.in ABSTRACT The present investigation was conducted to determine the variability, heritability, genetic advance and correlation of fruit yield and ten different yield contributing characters in bottle gourd. Wide range of variation was observed for most of the characters like fruit yield/vine, fruit number/vine, fruit weight, fruit yield/ha and node number for first female flower appearance. Phenotypic coefficient of variation was higher than genotypic coefficient of variation for all the traits studied, indicating environmental influence on expression of these characters. However, high heritability (broad sense) along with high genetic advance was recorded by vine length, branch number, fruit length, fruit width, fruit yield/vine and yield/ha indicating the presence of additive gene effects, hence selection can be employed for the improvement of these parameters. Fruit yield/ ha was significantly and positively associated with fruit number/ vine and fruit yield/vine both at genotypic as well as phenotypic levels. Fruit number had maximum direct effect (0.812) on fruit yield/ha followed by fruit weight (0.407), fruit length (0.339), fruit width (0.310), fruit yield/vine (0.249), days taken for first female flower appearance (0.224) and vine length (0.173). Therefore for the yield improvement in bottle gourd, emphasis may be given for indirect selection through fruit parameters like fruit weight, fruit length, fruit number and fruit yield/vine. Key words: Bottle gourd, genetic variability, heritability, path analysis Original Research Paper INTRODUCTION Bottle gourd [Lagenaria siceraria (Mol.) Standl.] commonly known as Lauki or Ghiya in India is one of the most important member of the family Cucurbitaceae and believed to be originated in Africa (Whitaker, 1971). It is commercially grown in all the states of India in both rainy and summer seasons. The immature fruits contain good amount of vitamins and have good medicinal values. Yield is a complex trait influenced by genetic fa ctor s inter a cting with environment. Success in any breeding programme for improvement depends on existing genetic variability in the base-population and on efficiency of selection. For successful selection, it is necessary to study the nature of association of the trait of interest with other relevant traits and, also the genetic variability available for these. Path coefficient provides a better index for selection than mere correlation coefficient, thereby separating the correlation coefficient of yield and its components into direct and indirect effects. Therefore, the present study was undertaken to understand the nature and magnitude of variability, heritability, correlation coefficients and path analysis for different quantitative parameters in bottle gourd. The information on such aspects can be of great help in formulating an appropriate breeding strategy for genetic upgradation of this crop. MATERIAL AND METHODS T he exper iments wer e car ried out a t the Vegetable Farm, ICAR-Indian Institute of Horticultural Research, Bengaluru during Rabi-summer seasons of 2012-13 and 2013-14. The experiments were laid out in Randomized Block Design with 35germplasm lines in two replications in both the years. Ten plants per replication were raised. Two weeks old seedlings were planted at 200 x 60 cm spacing and the plants were trained on single trellis. The recommended agronomical practices were adopted to raise the crop. Observations 132 J. Hortl. Sci. Vol. 13(2) : 131-136, 2018 Varalakshmi et al were recorded on five randomly selected plants from each replication on 11 quantitative traits such as node number for first female flower appearance, days taken for first female flower appearance, vine length (m), branch number, peduncle length (cm), fruit length (cm), fruit girth (cm), fruit number/plant, fruit weight (g), fruit yield/plant (kg) and fruit yield/ha (t). The pooled data of two years were analyzed as suggested by Panse and Sukhatme (1984) for analysis of variance. The phenotypic and genotypic coefficients of variation (PCV and GCV), heritability in broad sense a nd genetic advance a s per cent of mean wer e calculated as per the procedures given by Burton and De Vane (1953) and Johnson et al (1955). The correlation co-efficient among all possible character combinations at genotypic (rg) and phenotypic (rp) level were estimated employing the formula given by Al- Jibouri et al (1958) and path coefficient analysis has been done as per Dewey and Lu (1959). GENRES Statistical Software Package (GENRES, 1994) was employed for analysis of variance and estimation of correlation among the traits. RESULTS AND DISCUSSION Mean, range and estimates of various genetic pa r a meter s of 11 differ ent cha r a cter s of the 35germplasm lines of bottle gourd are presented in the Table 1. The analysis of variance revealed significant differences among the germplasm lines of bottle gourd for all the 11traits studied. Wide range of variation was observed for most of the characters like fruit yield/ vine (1.5-8.5kg), fruit number/vine (1.9-6.1), fruit weight (79.8-300.8g), fruit yield/ha (12.0-70.9 t)and node number for first female flower appearance (4.7- 15.2). Presence of such high variability for these parameters will form the basis for effective selection of superior lines in bottle gourd. Such wide variability in this crop has also been reported by Kumar et al (2011), Husna et al (2011), Anchal Sharma and Sengupta (2013) and Ara et al (2014). The degree of variability shown by different parameters can be judged by the magnitude of GCV and PCV. GCV, which gives the picture of extent of genetic variability present in the population ranged from 9.2 (days taken for first female flower appearance) to 31.2 (fruit yield/vine). Similar findings were reported by Yadavet al (2008), Husnaet al (2011) and Araet al (2014) in bottle gourd.A perusal of data in Table 1showed that there is considerable difference between PCV and GCV values for all the characters studied (Singh et al, 2008). This indicates the presence of higher environmental influence on the expression of all these parameters Table 1. Means, coefficients of variation, heritability and genetic advance for eleven different characters in bottle gourd Sl.No. Character Mean Range Genotypic Phenotypic Heritability G.A.as %mean Coefficient of Coefficient of (h2) Variation Variation (GCV) (PCV) 1 Vine length (m) 4.8 2.8-8.9 27.1 29.7 83.3 50.9 2 Branch number 12.5 7.3-20.8 20.9 26.9 60.5 33.5 3 NFF 7.2 4.7-15.2 23.3 31.6 54.2 35.3 4 DFF 56.1 45.5-71.7 9.2 11.5 64.1 15.2 5 Peduncle length (cm) 10.6 6.8-14.1 11.0 22.2 24.7 11.3 6 Fruit length (cm) 31.8 11.2-48.5 24.9 28.4 77.2 45.2 7 Fruit width (cm) 9.0 6.9-13.2 19.8 23.4 71.6 34.6 8 Fruit weight (g) 1.3 0.5-2.6 22.5 31.9 49.7 32.7 9 Fruit number/vine 3.7 1.9-6.1 26.1 33.8 59.7 41.6 10 Fruit yield/vine (kg) 4.2 1.5-8.5 31.2 36.5 73.3 55.1 11 Fruit yield/ha (t) 36.2 12.0-70.9 29.7 33.0 80.8 54.9 NFF- Node number for first female flower appearance, DFF- Days taken for first female flower appearance 133 Genetic studies in bottle guard and selection as such may not be effective for the improvement of bottle gourd. Further, the GCV values were low in magnitude compared to PCV values for all the characters studied. This also indicates that the direct selection is not effective for these characters and heterosis breeding can be resorted for further improvement. However, contrary to this Anchal Sharma and Sengupta (2013) reported that the GCV and PCV values were in close proximity for all the traits studied in bottle gourd. With the help of GCV alone, it is not possible to determine the extent of variation that is heritable. Thus the estimates of heritability indicate the effectiveness with which selection can be expected to exploit the existing genetic variability. The broad sense heritability was high (>60%) for almost all the traits except node number for first female flower appearance, peduncle length, fruit weight and fruit number. Similar findings were reported by Kumar et al (2011), Husna et al (2011) and Anchal Sharma and Sengupta (2013) in bottle gourd. Moderate heritability (40-60%) was observed for node number for first female flower appearance, fruit weight and fruit number (Table 1). Johnson et al. (1955) reported that the heritability along with genetic advance is more useful than the heritability alone in predicting the resultant effect of selecting best individual genotype as it suggests the presence of additive gene effects. In the present study, high heritability along with high genetic advance was recorded by vine length, branch number, fruit length, fruit width, fruit yield/vine and yield/ha indicating the presence of additive gene effects, hence selection can be employed for the improvement of these parameters in bottle gourd. Similar findings were reported by Singh et al (2008), Yadav et al (2008), Husna et al (2011),Kumar et al (2011), Anchal Sharma and Sengupta (2013) in bottle gourd. Days taken for the first female flower appearance, peduncle length and fruit weight have recorded moderate heritability and genetic advance. This suggests that the environmental effects constitute major portion of total phenotypic variation and hence direct selection for these characters will be less effective. All possible correlation coefficients between fruit yield/ha and its component characters were estimated at genotypic (G) and phenotypic (P) levels and have been presented in Table 2. From these associations, it appeared that higher fruit yield/ ha was significantly and positively associated with fruit number/ vine and fruit yield/vine both at genotypic as well as phenotypic levels. In the present investigation, the interrelation between these two yield contributing parameters was also positive and significant. Vine length had significantly positive correlation with branch number, node number and days taken for first female flower appearance and positive but non-significant association with fruit width. Branch number was also positively correlated with node number and days taken for first female flower appearance and fruit width, but negatively and significantly correlated with fruit weight indicating that the increased branch number reduces fruit weight in bottle gourd. Important fruit traits, fruit length and fruit width are significantly negatively correlated. Indirect selection for fruit number and fruit yield/vine will improve the fruit yield in bottle gourd. These results are in conformity with the findings of Yadav et al (2007), Wani et al (2008), Husna et al (2011) and Ara et al (2014) in bottle gourd. Though the correlation analysis can quantify the degree of association between two characters, it does not provide reasons for such association. The simple linear correlation coefficient is designed to detect the presence of linear association between two variables. It cannot be taken to imply the absence of any functional relationship between the two variables. Path coefficient analysis reveals this mystery by breaking the total correlation into components of direct and indirect effects. Thus path analysis was performed to assess the direct and indirect effects of different characters on fruit yield/ha (Table 3). Fruit number had maximum direct effect (0.812) on fruit yield/ha followed by fruit weight (0.407), fruit length (0.339), fruit width (0.310), fruit yield/vine (0.249), days taken for first female flower appearance (0.224) and vine length (0.173). The indirect effects of most other parameters through these parameters were also positive as well as negative, but the higher magnitude of positive direct effects nullified the negative indirect effects resulting in the positive direct effect on fruit yield/ha. The positive direct and indirect effects of fruit number and fruit yield/vine have lead to the significant and positive correlation with fruit yield/ha. Similarly, Wani et al (2008) and Husna et al (2011) also reported that fruit traits had maximum direct effect on fruit yield J. Hortl. Sci. Vol. 13(2) : 131-136, 2018 134 J. Hortl. Sci. Vol. 13(2) : 131-136, 2018 Varalakshmi et al C ha ra ct er V in e B ra nc h N FF D FF Pe du nc le Fr ui t Fr ui t Fr ui t Fr ui t Fr ui t Fr ui t L en gt h N um be r le ng th le ng th w id th w ei gh t nu m be r/ Y ie ld /v in e Y ie ld /h a (m ) (c m ) (c m ) (c m ) (g ) vi ne (k g) (t) V in e l en gt h (m ) (r g) 1. 00 0 0. 58 7* * 0. 68 2* * 0. 71 1* * -0 .3 23 -0 .1 81 0. 28 8 -0 .2 38 -0 .0 19 -0 .0 83 -0 .0 96 (r p) 1. 00 0 0. 40 3* 0. 45 8* * 0. 53 2* * -0 .1 22 -0 .1 56 0. 24 2 -0 .0 90 -0 .0 17 -0 .0 57 -0 .0 53 B ra nc h nu m be r (r g) 1. 00 0 0. 19 5 0. 27 4 -0 .3 33 -0 .1 10 0. 16 6 -0 .4 49 ** 0. 24 0 0. 05 1 -0 .0 52 (r p) 1. 00 0 0. 15 8 0. 24 6 -0 .1 48 -0 .0 65 0. 10 9 -0 .2 18 -0 .0 23 -0 .0 44 -0 .1 10 N FF (r g) 1. 00 0 0. 76 9* * -0 .1 88 -0 .2 66 0. 42 9* -0 .0 51 -0 .2 36 -0 .2 79 -0 .2 83 (r p) 1. 00 0 0. 54 2* * -0 .0 82 -0 .0 63 0. 30 0 0. 03 0 -0 .2 34 -0 .2 03 -0 .1 92 D FF (r g) 1. 00 0 -0 .1 82 -0 .2 88 0. 31 2 -0 .2 38 -0 .2 01 -0 .2 29 -0 .2 52 (r p) 1. 00 0 -0 .0 57 -0 .1 72 0. 28 3 -0 .1 44 -0 .1 12 -0 .1 68 -0 .1 80 Pe du nc le le ng th (c m ) (r g) 1. 00 0 0. 19 5 -0 .4 00 * 0. 49 7* * -0 .2 22 0. 05 8 0. 09 2 (r p) 1. 00 0 0. 11 3 -0 .1 40 0. 18 2 -0 .0 63 0. 02 9 0. 03 8 Fr ui t l en gt h (c m ) (r g) 1. 00 0 -0 .8 77 ** 0. 23 3 -0 .1 55 0. 01 6 0. 05 7 (r p) 1. 00 0 -0 .6 29 ** 0. 23 4 -0 .1 06 0. 03 4 0. 08 5 Fr ui t w id th (c m ) (r g) 1. 00 0 -0 .0 03 -0 .0 63 -0 .0 97 -0 .1 34 (r p) 1. 00 0 0. 01 8 -0 .0 44 -0 .1 29 -0 .1 06 Fr ui t w ei gh t ( g) (r g) 1. 00 0 -0 .3 04 0. 13 0 0. 31 5 (r p) 1. 00 0 -0 .2 79 0. 03 8 0. 21 4 Fr ui t n um be r/ vi ne (r g) 1. 00 0 0. 88 1* * 0. 79 2* * (r p) 1. 00 0 0. 72 2* * 0. 68 9* * Fr ui t y ie ld /v in e (k g) (r g) 1. 00 0 1. 00 3* * (r p) 1. 00 0 0. 87 6* * Ta bl e 2. G en ot yp ic ( r g ) an d ph en ot yp ic ( r p ) co rr el at io n co ef fic ie nt s am on g di ff er en t ch ar ac te rs i n bo tt le g ou rd ** S ig ni fic an t a t P = 0. 01 , * S ig ni fic an t a t P = 0. 05 N FF - N od e nu m be r fo r fir st f em al e flo w er a pp ea ra nc e, D FF - D ay s ta ke n fo r fir st f em al e flo w er a pp ea ra nc e 135 J. Hortl. Sci. Vol. 13(2) : 131-136, 2018 Genetic studies in bottle guard C ha ra ct er V in e B ra nc h N FF D FF Pe du nc le Fr ui t Fr ui t Fr ui t Fr ui t Fr ui t G en ot yp ic le ng th nu m be r le ng th le ng th w id th w ei gh t nu m be r/ yi el d/ vi ne co rr el at io n (m ) (c m ) (c m ) (c m ) (g ) vi ne (k g) V in e l en gt h (m ) 0. 17 3 -0 .0 96 -0 .1 93 0. 15 9 -0 .0 33 -0 .0 61 0. 08 9 -0 .0 97 -0 .0 16 -0 .0 21 -0 .0 96 B ra nc h nu m be r 0. 10 2 -0 .1 64 -0 .0 55 0. 06 1 -0 .0 34 -0 .0 37 0. 05 1 -0 .1 83 0. 19 4 0. 01 3 -0 .0 52 N FF 0. 11 8 -0 .0 32 -0 .2 84 0. 17 2 -0 .0 19 -0 .0 90 0. 13 3 -0 .0 21 -0 .1 92 -0 .0 69 -0 .2 83 D FF 0. 12 3 -0 .0 45 -0 .2 18 0. 22 4 -0 .0 19 -0 .0 98 0. 09 7 -0 .0 97 -0 .1 63 -0 .0 57 -0 .2 52 Pe du nc le le ng th (c m ) -0 .0 56 0. 05 5 0. 05 3 -0 .0 41 0. 10 2 0. 06 6 -0 .1 24 0. 20 2 -0 .1 80 0. 01 4 0. 09 2 Fr ui t l en gt h (c m ) -0 .0 31 0. 01 8 0. 07 5 -0 .0 65 0. 02 0 0. 33 9 -0 .2 72 0. 09 5 -0 .1 26 0. 00 4 0. 05 7 Fr ui t w id th (c m ) 0. 05 0 -0 .0 27 -0 .1 22 0. 07 0 -0 .0 41 -0 .2 97 0. 31 0 -0 .0 01 -0 .0 51 -0 .0 24 -0 .1 34 Fr ui t w ei gh t ( g) -0 .0 41 0. 07 4 0. 01 4 -0 .0 53 0. 05 1 0. 07 9 -0 .0 01 0. 40 7 -0 .2 47 0. 03 2 0. 31 5 Fr ui t n um be r/ vi ne -0 .0 03 -0 .0 39 0. 06 7 -0 .0 45 -0 .0 23 -0 .0 53 -0 .0 19 -0 .1 24 0. 81 2 0. 21 9 0. 79 2* * Fr ui t y ie ld /v in e (k g) -0 .0 14 -0 .0 08 0. 07 9 -0 .0 51 0. 00 6 0. 00 5 -0 .0 30 0. 05 3 0. 71 5 0. 24 9 1. 00 3* * Ta bl e 3 . D ir ec t an d in di re ct e ff ec ts o f di ff er en t ch ar ac te rs o n fr ui t yi el d/ ha a t ge no ty pi c le ve ls i n bo tt le g ou rd ** S ig ni fic an t a t P = 0. 01 , * S ig ni fic an t a t P = 0. 05 D ire ct e ff ec ts a re in b ol d fig ur es o n m ai n di ag on al . N FF - N od e nu m be r fo r fir st f em al e flo w er a pp ea ra nc e, D FF - D ay s ta ke n fo r fir st f em al e flo w er a pp ea ra nc e 136 J. Hortl. Sci. Vol. 13(2) : 131-136, 2018 Varalakshmi et al in bottle gourd. Whereas node number for first female flower appearance and branch number had negative direct effect on fruit yield/ha. The positive direct and indirect effects of fruit length, fruit weight, fruit yield/ plant, fruit number have lead to the significant and positive correlation with fruit yield/ha. This indicates that the positive selection for these parameters is going to contribute to higher fruit yields in bottle gourd. Therefore for the yield improvement in bottle gourd, emphasis may be given for indirect selection through fruit parameters like fruit length, fruit weight, fruit number and fruit yield/plant. REFERENCES Al-Jibouri, H.H., Miller, P.A. and Robinson, H.F. 1958.Genotypic and environmental variances and covariances in upland cotton crosses of interspecific origin.Agron. J., 50: 633-37. Anchal Sharma and S.K. Sengupta.2013. Genetic Diversity, Heritability and Morphological Cha r a cter iza tion in Bottle Gour d (Lagenariasiceraria (Mol. ) Sta nd). The Bioscan.8(4): 1461-1465. Ara Z.G., Zakaria, M., Uddin, M.Z., Rahman, M.M., Rasul, M.G. and Kabir, A.F.M.R. 2014. Correlation matrix among different parameters of bottle gourd genotypes Int. J Nat. Soc Sci.1:48-51. ISSN: 2313-4461 Burton, G.W. and De Vane, E.W. 1953. Estimating heritability in tall fescue (Festucaarundinacea) from replicated clonal material. Agron. J., 45:478-81. Dewey, D.R. and Lu, K.H. 1959. A correlation and path coefficient analysis of components of crested wheat grass seed production. Agron. J.,51:515-18. GENRES. 1994. Data entrymodule for genres statistical software Pascal Int’l. Software Solution, Version 3.11 Husna, A., Mahmud, F., Islam, M.R., Mahmud,M.A.A. a nd Ra tna , M. 2011. Genetic va r ia bility, correlation and path co - efficient analysis in bottle gour d (Lageneriasicereria(Mol. ) stand).Ad.Bio. Res. 5(6): 323-327. Johnson, H.W., Robinson, H.F. and Comstock, R.E. 1955. Estimates of genetic and environmental variability in soybean.Agron. J., 47:314-18. Kumar, A., Singh, B., Kumar,M. and Naresh,R.K. 2011.Genetic variability, heritability, genetic advance for yield and its components in bottle gourd (Lageneriasicereria(Mol.) stand).Ann. of Horti.4(1): 101-103 Panse, V.G. and Sukhatme, P.V. 1984. Statistical Methods for Agr icultural Workers.Indian Council of Agricultural Research, New Delhi. Singh,K.P., Choudhury,D.N., Mandal,G. and Saha,B.C. 2008. Genetic va r iability in bottle gour d (Lagenaria siceraria (Molina) Standl.).J. Interacademicia. 12(2): 159-163 Wani, K.P., Ahmed, N., Hussain, K., Mehfuza-Habib and Kant, R.H. 2008.Correlation and path coefficient a na lysis in bottle gour d (Lagenariasiceraria L.) under tempera te conditions of Kashmir valley.Environment and Ecology.26(2A): 822-824 Whitaker, T.W. 1971.Men across the sea. Kelley JC, Pennigton CW and Rauds RL (Eds.) pp. 320-27. Yadav, A., Srivastava, J.P., Yadav, J.R., Shukla, I.N., Mishr a , G. , Kuma r, S. a nd Pa r iha r, N. S. 2007.Correlation and path coefficient analysis in bottle gourd [Lagenariasiceraria (Molina) Standl.].Prog. Res.2(1/2): 165-166 Yadav, J.R., Yadav, A., Srivastava, J.P., Mishra, G., Parihar, N.S. and Singh,P.B. 2008. Study on variability heritability and genetic advance in bottle gourd [Lagenariasiceraria (Molina) Standl.]. Prog. Res.3(1): 70-72 (MS Received 22 June 2017, Revised 15 November 2018, Accepted 20 December 2018)