Highlights in BioScience ISSN:2682-4043 DOI:10.36462/H.BioSci.202106 Research Article Open Access 1 Genetics and Plant Improvement Team, Bio- sciences Laboratory, Doctoral School of Sci- ences and Technologies, Joseph KI-ZERBO University, 03 BP 7021 Ouagadougou 03, Burk- ina Faso. 2 Chadian Institute of Agronomic Research for Development (ITRAD), B.P. 5400, N’Djaména, Chad. 3 Plant Ecophysiology Team, Biosciences Labo- ratory, Doctoral School of Sciences and Tech- nologies, Joseph KI- ZERBO University, 03 BP 7021 Ouagadougou 03, Burkina Faso. 4 Ziniaré University Center, Joseph KI- ZERBO University, 03 BP 7021 Ouagadougou 03, Burkina Faso. Contacts of authors * To whom correspondence should be addressed: nerbewende@yahoo.fr Received: January 2, 2021 Accepted: March 4, 2021 Published: March 18, 2021 Citation: Tiendrébéogo KF, Sawadogo N, Gapili N, Ouédraogo MH, Ouédraogo RF, Nanema KR, Ouoba A, Sawadogo M . Variability and relationships between characters of physic nut (Jatropha curcas L.) in Burkina Faso . 2021 Mar 18;4:bs202106 Copyright: © 2021 Tiendrébéogo et al.. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribu- tion, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper and supplementary materials. Funding: The authors have no support or funding to report. Competing interests: The authors declare that they have no competing interests. Variability and relationships between characters of physic nut (Jatropha curcas L.) in Burkina Faso Kouka Fidèle Tiendrébéogo1, Nerbéwendé Sawadogo*1, Naoura Gapili2, Mahamadi Hamed Ouédraogo1, Razacswendé Fanta Ouédraogo3, Kiswendsida Romaric Nanema1, Adjima Ouoba4, Mahamadou Sawadogo1 Abstract Jatropha curcas is a highly promising species for biodiesel production in Burkina Faso and other countries in the tropics. It is rustic, grows in warm regions and is easily culti- vated. These characteristics and high-quality oil yields from the seeds have made it a pri- ority for biodiesel programs. Consequently, this plant merits genetic investigations aimed at improving yields. The present study was conducted to determine the extent of genetic variability and relationships among 30 accessions from Burkina Faso using 7 qualitative characters and 20 quantitative characters. For most of the traits, there were highly sig- nificant differences among the accessions. A positive and significant correlation between the 100-seed weight trait and the oil content trait was observed. The oil content trait is significantly and positively influenced by growth traits such as plant height and crown di- ameter. Based on the petiole base pigmentation, three morphotypes were identified: green morphotype, purple morphotype and brown morphotype. The green morphotype was char- acterized by very high oil content and high 100-seed weight while the brown morphotype presents low oil content and low 100-seed weight. The purple morphotype registered a high oil content and medium 100-seed weight. These results are important for the continu- ity of breeding programs, aimed at obtaining cultivars with high grain yield and high oil content in seeds. Keywords: Oil content, Genetic diversity, Genetic correlation, Morphotype, Jatropha curcas, Burkina Faso. Introduction Physic nut (Jaropha curcas L.) is a perennial oil plant commonly used in tropical areas as a medicinal plant, in the construction of defensive hedges against animals and in the fight against water erosion [1]. It is rustic, grows in warm regions and is easily cultivated. These characteristics and high-quality oil yields from the seeds have made this plant a priority and a highly promising species for biodiesel programs in countries in the tropics [2]. It produces seeds rich in oil which can be used pure after filtration as fuel in diesel engines with indirect injection or serve as raw material for the production of biodiesel by transesterification [3, 4]. [5] highlighted the economic interest of the use of oil of this species for the poor countries, in particular tropical Africa and Asia. Indeed, J. curcas provides various products that contribute to poverty reduction, in particular the promotion of income-generating activities mainly for women such as sale of seeds and soap and the valuation of oil cakes as organic fertilizers. It is an opportunity for developing countries to improve farmers' incomes and even stimulate the rural economy [6]. However, in most countries of sub-Saharan Africa, the establishment of plantations preceded the conduct of agronomic research essential for the sustainable exploitation of the plant. As a result, plant development has been poor and yields obtained during the first years of cultivation have generally been disappointing [7]. Consequently, this species merits genetic investigations aimed at improving yields [2]. So, the viability of the J. curcas-based biodiesel sector is essentially based on highly productive and oil-rich J. curcas genotypes [6]. Highlights in BioScience Page 1 of 11 March 2021|Volume 4 https://doi.org/10.36462/H.BioSci.202106 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://orcid.org/0000-0002-0448-4239 https://orcid.org/0000-0003-0136-8408 https://orcid.org/0000-0001-6415-8745 https://orcid.org/0000-0002-3037-8624 https://orcid.org/0000-0002-4241-4696 https://orcid.org/0000-0001-8913-1012 https://orcid.org/0000-0001-6456-2297 http://bioscience.highlightsin.org/ Tiendrébéogo et al., 2021 Variability and relationships between characters of physic nut (Jatropha curcas L.) Despite strong recommendations for improvement of J. cur- cas for intensive production, a very little references exist on the genetic characteristics of the plant, the level of productivity of J. curcas in relation to its genetic potential and the cultivation techniques [6]. Indeed, J. curcas is still essentially a wild plant which must be the object of genetic improvement and domesti- cation for its popularization and vaolrization [8, 9]. In Burkina Faso, the genetic diversity of the species remains still poorly known [10-13]. Thus, within the framework of the promotion of the neglected or under-exploited local species, this study was ini- tiated in order to contribute to a better knowledge the genetic di- versity and the relationships between agro-morphological traits and seeds oil content of J. curcas. Material and methods Plant material The plant material consisted of 30 elite accessions selected by [11] based on the morpho-metric characteristics of the fruits as well as the oil content of the seeds. In this study, an acces- sion is a set of seeds, from natural pollination, harvested from the same tree during prospecting. The seeds were stored at labo- ratory temperature without any prior chemical treatment. Experimental site The agro-morphological characterization was carried out on a plantation installed in the experimental station of the Institute for Rural Development (IDR) of Gampela at 1°21'0.9'' West lon- gitude, 12°24'10.7'' North latitude and 924 m altitude. The sta- tion is characterized by very heterogeneous, deep soils, of low physicochemical fertility and a predominantly sandy-clay tex- ture [14]. The climate of the zone is of the sudano-sahelian type characterized by the alternation of two seasons, namely a rainy season which extends from june to october and a dry season from november to may [15]. The annual rainfall recorded in the sta- tion during the experimentation varied between 728 and 984.8 mm. Average air temperatures during the rainy months range between 35° C and 40° C for the maximums and between 18° C and 19° C for the minimums [15]. Experimental design The experimental design used is a completely random exper- iment plan consisting of 30 elementary plots of 8 m x 8 m. Each elementary plot contains 9 plants arranged in three lines of 8 m in length each. The spacing between the lines was 4 m. Each line includes three plants with a spacing of 4 m. The aisles between the elementary plots were also 4 m. Characters studied Qualitative characters Based on the work of [16], seven qualitative variables were chosen to characterize the phenotypic variability of the acces- sions studied. The Table 1 presents the different characters with their modalities. Table 1. Modalities of qualitative traits. Variables Modalities Brancing pattern Basal Intermdiate Top Entire Petiole base pigmentation Green Brown Purple Stem colour Green Grey Leaf colour Green Light green Dark green Latex colour Cream Red Phyllotaxy Alternate Whorled Growth habit Shurb (< 5 m) Tree (> 5m) Quantitative characters Based on the work of [17, 2, 18, 16, 6], 20 quantitative vari- ables were chosen to characterize the genetic diversity of J. cur- cas five years after planting. These parameters were measured on three plants sampled by accession. These are first of all the pa- rameters linked to the vegetative development of the trees, mea- sured three months after the appearance of the first leaves. Those are: • The dendrometric characters of trees such as plant height (PH) measured from the base to the apex of the main stem, crown diameter (CD) measured between both ends of the plant, stem diameter (SD) measured at the collar using a tape measure (SD = collar circumference / π) and number of main branches (NB) evaluated by counting the branches coming out from the trunk . • The characters linked to the dimensions of the leaves mea- sured on three fresh leaves, fully developed and not par- asitized, per individual: these were the width of the leaf (WL) measured between the two ends of the leaf, the length of the leaf (LL) measured from the petiole to the tip of the leaf and the length of the petiole (LP) measured from the insertion of the stem to the insertion of the leaf. The traits linked to the productivity of the accessions such as fruits weight (FRW), seeds weight (SEW) and pulps weight (PUW) per accession were also evaluated at the ripe and dry fruit stage using an electric scale. Moreover, others traits relative to the fruits were measured. They are the average length of the fruit (ALF), the average diameter of the fruit (ADF) evaluated using a digital caliper, the average weight of the fruit (AWF) and the average weight of the pulp (AWP) determined using an electric Highlights in BioScience Page 2 of 11 March 2021|Volume 4 http://bioscience.highlightsin.org/ Tiendrébéogo et al., 2021 Variability and relationships between characters of physic nut (Jatropha curcas L.) scale on ten fruits. The average number of seeds per fruit (ANS) was determined by counting. As concerning the seeds, the characters measured were the 100-seed weight (SW100) determined by weighing a random sample of 100 seeds of each mother plant using an electric scale, the average length of the seed (ALS), the average width of the seed (AWS) and the average thickness of the seed (ATS) mea- sured with a digital caliper on ten seeds. The seeds oil content (OIL) was determined by the soxhlet extraction method using hexane as the solvent [19]. [16] proposed a descriptor with four classes based on the seeds oil content character in relation with the weight of the seed: low (0-20%), medium (21-30%), High (31-40%) and very high (> 40%). Data analysis The data collected were analyzed with XLSTAT 2020.3.1.11 software. Analysis of variance (ANOVA) and of Student New- man Keuls means separation test at α=5% were carried out in order to compare accessions. Pearson’s R coefficient was used to measure correlations between quantitative traits while the rela- tionships between discriminate qualitative and quantitative traits were determined through multiple correspondence analysis (MCA). Indeed, the quantitative traits have been previously transformed into qualitative traits according to the classes obtained in the Stu- dent Newman Keuls means separation test. Results Analysis of the phenotypic variability of J. curcas using qualitative variables The results recorded in Table 2 showed that all the accessions studied had green stems and green leaves, a cream-colored latex and alternate leaves. However, two characters presented variabil- ity. Thus, the majority of plants (70%) had a basal branching pat- tern while a minority (30%) revealed an intermediate branching pattern (Figure 1). The petiole base expressed several pigmen- tation color (Figure 2): green (33.33%), brown (13.33%) and mostly purple (53.34%). Analysis of the phenotypic variability of J. curcas using quantitative variables The results of the significance of the means separation test of Newman Keuls were performed with vegetative development parameters (Table 3), fruit parameters (Table 4) and seeds param- eters (Table 5). Most of the vegetative development parameters and seeds traits significantly discriminate the accessions studied except the length of the petiole (LP), the average length of the seed (ALS) and seeds weight per accession (SEW). For the fruit traits, only three of the seven measured characters, precisely the average length of the fruit (ALF), the average weight of the fruit (AWF) and the average weight of the pulp (AWP) showed vari- ability. Based on the each of three characters of interest namely oil content (OIL), 100-seed weight (SW100) and crown diameter (CD), three classes were obtained within accessions. Indeed, ac- cording to the value of the character, three performance classes Table 2. Variation in the qualitative characters of the collection of J. curcas. Variables Modalities Frequencies (%) Brancing pattern Basal 70 Intermdiate 30 Top 0 Entire 0 Petiole base pigmentation Green 33.33 Brown 13.33 Purple 53.34 Stem colour Green 100 Grey 0 Leaf colour Green 100 Light green 0 Dark green 0 Latex colour Cream 100 Red 0 Phyllotaxy Alternate 100 Whorled 0 Growth habit Shurb (< 5 m) 100 Tree (> 5m) 0 (low, medium, high) were registered with the 100-seed weight trait and crown diameter, respectively. The seeds oil content character showed also three performance classes which ranged medium, high and very high according to the descriptor classes. Relationships between characters Correlation between characters The correlation of Pearson (Table 6) showed positive and significant correlations at the 5% and 1% threshold between the characters studied. Thus, the character oil content was positively correlated with the characters 100-seed weight (r = 0.253), plant height (r = 0.344) and crown diameter (r = 0.260). The 100- seed weight character was positively correlated with the charac- ters linked to vegetative development such as plant height (r = 0.522), crown diameter (r = 0.443) and length of the petiole (r = 0.272). Furthermore, the crown diameter character is positively correlated with all the other characters studied. These different correlations indicate that plants with significant vegetative devel- opment produce seeds of high weight and high oil content. The characters linked to the yield (FRW, SEW and PUW) are posi- tively correlated with the characters relating to the scale of the plant (PH, SD and CD). So, large-scale plants have also high productive potential. Furthermore, the characters of the seeds (ALS, AWS and ATS) are positively influenced each other. Association between characters The results of multiple correspondence analysis (MCA) reco- rded in Figure 3 showed three associations of the characters. On the plan formed by axes 1 and 2 with 45.41% of the total in- ertia, the F1 axis (23.14% of total inertia) opposed two groups of variables precisely group 1 and group 3. Group 1 combined the characters very high seed oil content (> 40%), intermediate Highlights in BioScience Page 3 of 11 March 2021|Volume 4 http://bioscience.highlightsin.org/ Tiendrébéogo et al., 2021 Variability and relationships between characters of physic nut (Jatropha curcas L.) Figure 1. Branching pattern of J. curcas. A: Basal (70%), B: Intermediate (30%). Figure 2. Petiole base pigmentation of J. curcas A: Green (33.33%), B: Brown (13.33%), C: Purple (53.34%) Highlights in BioScience Page 4 of 11 March 2021|Volume 4 http://bioscience.highlightsin.org/ Tiendrébéogo et al., 2021 Variability and relationships between characters of physic nut (Jatropha curcas L.) Table 3. Results of Newman Keuls'means separation test on vegetative development parameters. Accession PH (m) SD (cm) CD (m) NB WL (cm) LL (cm) LP (cm) 1 2.450 bcde 9.076 b 2.650 abc 4.000 b 16.295 abc 14.365 abc 20.165 a 2 1.977 cde 15.711 ab 2.733 abc 6.333 ab 15.130 abc 14.127 abc 17.197 a 3 2.600 bcd 12.527 ab 3.100 abc 5.667 ab 15.040 bc 13.477 abc 17.007 a 4 2.747 b 13.896 ab 3.717 ab 6.000 ab 17.207 abc 15.497 abc 18.997 a 5 2.490 bcde 15.977 ab 3.467 abc 6.000 ab 14.410 c 13.930 abc 17.167 a 6 2.150 bcde 13.694 ab 3.350 abc 5.500 ab 15.545 abc 13.545 abc 18.430 a 7 2.033 bcde 13.694 ab 3.000 abc 5.000 ab 17.477 abc 14.720 abc 16.983 a 8 2.567 bcd 13.907 ab 3.133 abc 5.000 ab 18.850 ab 16.687 a 18.430 a 9 2.567 bcd 14.756 ab 3.150 abc 5.667 ab 18.463 ab 15.710 abc 19.820 a 10 2.383 bcde 12.909 ab 3.000 abc 5.667 ab 16.597 abc 14.797 abc 16.943 a 11 2.017 bcde 12.707 ab 2.857 abc 7.667 ab 16.333 abc 14.043 abc 16.863 a 12 3.225 a 13.854 ab 3.500 abc 9.000 a 18.415 ab 15.930 ab 19.195 a 13 2.100 bcde 12.739 ab 2.800 abc 5.000 ab 14.895 bc 12.460 c 14.945 a 14 2.233 bcde 14.862 ab 3.150 abc 6.000 ab 17.283 abc 14.997 abc 16.710 a 15 2.017 bcde 15.287 ab 2.733 abc 8.000 ab 16.763 abc 14.517 abc 15.467 a 16 2.047 bcde 15.287 ab 2.900 abc 5.333 ab 16.177 abc 13.410 abc 16.310 a 17 2.227 bcde 13.163 ab 3.167 abc 4.667 ab 16.553 abc 14.483 abc 18.073 a 18 2.275 bcde 15.287 ab 3.450 abc 8.000 ab 16.350 abc 15.015 abc 18.795 a 19 2.683 bc 13.376 ab 4.000 a 6.333 ab 18.997 a 16.630 a 19.553 a 20 2.340 bcde 13.641 ab 3.400 abc 4.333 ab 16.693 abc 14.753 abc 18.310 a 21 2.225 bcde 13.694 ab 2.900 abc 9.000 a 17.545 abc 14.910 abc 18.130 a 22 2.417 bcde 12.781 ab 2.867 abc 7.000 ab 16.910 abc 14.340 abc 17.517 a 23 1.915 de 10.987 ab 2.650 abc 4.000 b 15.530 abc 12.900 bc 13.995 a 24 1.900 de 14.411 ab 2.635 abc 7.000 ab 15.965 abc 14.130 abc 18.365 a 25 1.770 e 10.403 ab 2.100 c 5.667 ab 15.387 abc 12.683 bc 15.297 a 26 2.267 bcde 10.032 ab 2.600 abc 3.667 b 17.940 abc 15.440 abc 17.097 a 27 1.857 de 12.951 ab 2.400 bc 5.667 ab 14.953 bc 12.730 bc 14.617 a 28 2.183 bcde 16.561 ab 2.767 abc 7.000 ab 16.217 abc 13.463 abc 16.410 a 29 1.880 de 17.304 a 2.767 abc 6.000 ab 15.573 abc 13.797 abc 15.750 a 30 1.900 de 11.996 ab 2.700 abc 4.333 ab 16.420 abc 14.697 abc 16.017 a PH: plant height, SD: stem diameter, CD: crown diameter, NB: number of main branches, WL: width of the leaf, LL: length of the leaf, LP: length of the petiole. The values for each class followed by the same letters are not significantly different at the 5% level. branching of the stem, green pigmentation of the petiole base, high 100-seed weight (≥ 62.85 g) and large crown diameter (≥ 4 m) while the group 3 is formed by association between the medium oil content (21-30%), the brown pigmentation of the petiole base and the low 100-seed weight (≤ 36.9 g). Group 2, correlated to axis F2 with 22.127% of total inertia, combined the high oil content (31-40%), the basal branching of the stem, the purple pigmentation of the petiole base, the medium 100-seed weight (43.30-43.85 g), the medium crown diameter (2.4-3.467 m) and the small crown diameter (≤ 2.1 m). Highlights in BioScience Page 5 of 11 March 2021|Volume 4 http://bioscience.highlightsin.org/ Tiendrébéogo et al., 2021 Variability and relationships between characters of physic nut (Jatropha curcas L.) Table 4. Results of Newman Keuls'means separation test on fruits parameters. Accession ALF (cm) ADF (cm) AWF (g) AWP (g) ANS FRW (g) PUW (g) 1 2.533 ab 2.110 a 2.610 ab 0.940 ab 2.550 a 158.400 a 49.900 a 2 2.265 ab 2.058 a 1.843 ab 0.790 abcd 2.500 a 207.233 a 94.867 a 3 2.425 ab 2.120 a 2.623 ab 0.920 abc 2.700 a 263.167 a 93.567 a 4 2.457 ab 2.080 a 2.460 ab 0.873 abc 2.800 a 509.200 a 189.900 a 5 2.340 ab 2.053 a 2.430 ab 0.837 abcd 2.833 a 541.667 a 211.600 a 6 2.468 ab 2.083 a 2.710 ab 1.005 a 2.950 a 816.250 a 317.450 a 7 2.383 ab 2.090 a 1.840 ab 0.670 bcd 2.200 a 136.967 a 56.733 a 8 2.478 ab 2.158 a 2.120 ab 0.757 abcd 2.467 a 163.767 a 68.467 a 9 2.535 ab 2.100 a 2.277 ab 0.837 abcd 2.667 a 463.867 a 210.133 a 10 2.425 ab 2.117 a 2.143 ab 0.720 abcd 2.500 a 249.433 a 100.367 a 11 2.402 ab 2.067 a 2.300 ab 0.930 abc 2.633 a 248.233 a 114.567 a 12 2.430 ab 2.140 a 2.500 ab 0.830 abcd 2.750 a 453.500 a 168.300 a 13 2.498 ab 2.035 a 2.175 ab 0.895 abc 2.850 a 641.400 a 256.050 a 14 2.483 ab 2.078 a 2.133 ab 0.880 abc 2.567 a 433.867 a 172.033 a 15 2.130 b 1.998 a 1.417 b 0.547 d 2.367 a 174.767 a 79.533 a 16 2.567 a 2.158 a 2.773 a 0.877 abc 2.967 a 496.000 a 190.900 a 17 2.425 ab 2.045 a 2.120 ab 0.750 abcd 2.600 a 384.400 a 161.667 a 18 2.593 a 2.145 a 2.530 ab 0.770 abcd 2.850 a 834.300 a 277.150 a 19 2.395 ab 2.093 a 2.493 ab 0.750 abcd 2.967 a 774.267 a 287.667 a 20 2.397 ab 2.078 a 2.380 ab 0.750 abcd 2.833 a 836.400 a 323.800 a 21 2.420 ab 2.073 a 2.115 ab 0.660 bcd 2.750 a 158.850 a 59.700 a 22 2.393 ab 2.112 a 1.940 ab 0.733 abcd 2.533 a 162.800 a 73.567 a 23 2.460 ab 2.088 a 2.015 ab 0.670 bcd 2.600 a 99.600 a 39.100 a 24 2.330 ab 1.940 a 1.770 ab 0.607 cd 2.230 a 86.400 a 37.350 a 25 2.205 ab 1.927 a 1.627 ab 0.608 cd 2.420 a 89.200 a 39.600 a 26 2.380 ab 2.083 a 1.797 ab 0.713 abcd 2.133 a 64,933 a 29.600 a 27 2.212 ab 1.978 a 1.537 ab 0.637 bcd 2.200 a 97.867 a 49.033 a 28 2.368 ab 2.088 a 1.830 ab 0.833 abcd 2.333 a 147.533 a 71.133 a 29 2.245 ab 1.945 a 1.800 ab 0.870 abc 2.100 a 89.300 a 40.000 a 30 2.192 ab 2.043 a 1.607 ab 0.843 abcd 2.067 a 78.100 a 43.933 a ALF: average length of the fruit, ADF: average diameter of the fruit, AWF: average weight of the fruit, AWP: average weight of the pulp, ANS: average number of the seeds per fruit, FRW: fruits weight per accession, PUW: pulps weight per accession. The values for each class followed by the same letters are not significantly different at the 5% level. Highlights in BioScience Page 6 of 11 March 2021|Volume 4 http://bioscience.highlightsin.org/ Tiendrébéogo et al., 2021 Variability and relationships between characters of physic nut (Jatropha curcas L.) Table 5. Results of Newman Keuls'means separation test on seeds parameters. Accession ALS (cm) AWS (cm) ATS (cm) SW100 (g) SEW (g) OIL (%) 1 1.830 a 1.120 ab 0.863 ab 56.100 ab 108.500 a 33.811 i 2 1.755 a 1.092 ab 0.835 ab 47.833 abc 112.367 a 31.160 lm 3 1.803 a 1.150 ab 0.868 a 63.350 a 169.600 a 35.897 g 4 1.833 a 1.113 ab 0.855 ab 62.850 a 319.300 a 34.663 h 5 1.753 a 1.068 b 0.818 ab 55.833 ab 330.067 a 39.286 c 6 1.845 a 1.173 a 0.853 ab 61.100 ab 498.800 a 31.309 l 7 1.813 a 1.092 ab 0.847 ab 55.600 ab 80.233 a 35.023 h 8 1.833 a 1.123 ab 0.865 ab 52.900 abc 95.300 a 32.874 j 9 1.890 a 1.068 b 0.835 ab 53.300 abc 253.733 a 37.931 e 10 1.827 a 1.098 ab 0.873 a 54.933 ab 149.067 a 35.474 g 11 1.753 a 1.130 ab 0.850 ab 54.450 ab 133.667 a 37.989 e 12 1.780 a 1.073 b 0.845 ab 63.700 a 285.200 a 37.931 e 13 1.753 a 1.065 b 0.813 ab 43.850 bc 385.350 a 32.360 k 14 1.868 a 1.060 b 0.835 ab 48.500 abc 261.833 a 40.383 b 15 1.688 a 1.063 b 0.813 ab 45.900 abc 95.233 a 31.331 l 16 1.840 a 1.118 ab 0.852 ab 58.333 ab 305.100 a 29.366 o 17 1.792 a 1.107 ab 0.825 ab 55.233 ab 222.733 a 31.577 l 18 1.813 a 1.120 ab 0.870 a 64.300 a 557.150 a 32.486 jk 19 1.832 a 1.152 ab 0.857 ab 59.200 ab 486.600 a 40.863 a 20 1.765 a 1.125 ab 0.832 ab 63.250 a 512.600 a 34.726 h 21 1.840 a 1.118 ab 0.853 ab 52.450 abc 99.150 a 30.800 mn 22 1.805 a 1.065 b 0.832 ab 64.000 a 89.233 a 32.463 jk 23 1.808 a 1.088 ab 0.828 ab 54.400 ab 60.500 a 32.760 jk 24 1.740 a 1.090 ab 0.868 ab 43.300 bc 49.050 a 30.474 n 25 1.663 a 1.070 b 0.800 b 50.200 abc 49.600 a 34.040 i 26 1.780 a 1.113 ab 0.847 ab 53.200 abc 35.333 a 36.909 f 27 1.707 a 1.065 b 0.817 ab 51.600 abc 48.833 a 38.640 d 28 1.782 a 1.060 b 0.832 ab 43.500 bc 76.400 a 31.617 l 29 1.672 a 1.067 b 0.837 ab 47.100 abc 49.300 a 35.549 g 30 1.687 a 1.112 ab 0.853 ab 36.900 c 34.167 a 28.137 p ALS: average length of the seed, AWS: average width of the seed, ATS: average thickness of the seed, SW100: 100-seed weight, SEW: seeds weight per accession, OIL: seeds oil content. The values for each class followed by the same letters are not significantly different at the 5% level. Highlights in BioScience Page 7 of 11 March 2021|Volume 4 http://bioscience.highlightsin.org/ Tiendrébéogo et al., 2021 Variability and relationships between characters of physic nut (Jatropha curcas L.) Ta bl e 6. M at ri x of co rr el at io ns be tw ee n th e st ud ie d ch ar ac te rs . V ar ia bl es A L F A D F A W F A W P A N S A L S A W S A T S S W 10 0 O IL P H S D C D N B W L L L L P F R W S E W A D F 0. 78 7* * A W F 0. 74 5* * 0. 62 7* * A W P 0. 58 8* * 0. 49 3* * 0. 70 6* * A N S 0. 59 8* * 0. 55 0* * 0. 83 6* * 0. 46 9* * A L S 0. 86 0* * 0. 78 7* * 0. 61 3* * 0. 43 3* * 0. 50 9* * A W S 0. 39 1* * 0. 46 3* * 0. 52 0* * 0. 35 9* * 0. 41 8* * 0. 43 2* * A T S 0. 42 3* * 0. 40 2* * 0. 39 2* * 0. 31 6* * 0. 04 1 0. 47 0* * 0. 52 1* * S W 10 0 0. 39 2* * 0. 35 0* * 0. 57 0* * 0. 19 1 0. 42 8* * 0. 32 4* * 0. 32 0* * 0. 22 6* O IL 0. 07 6 0. 01 2 0. 15 5 0. 08 9 0. 10 0 0. 14 0 -0 .0 62 -0 .0 53 0. 25 3* P H 0. 41 8* * 0. 41 3* * 0. 49 9* * 0. 27 7* 0. 38 7* * 0. 45 9* * 0. 18 6 0. 32 6* * 0. 52 2* * 0. 34 4* * S D 0. 06 7 0. 09 7 0. 10 2 0. 19 4 0. 07 0 0. 05 9 -0 .1 75 0. 11 6 0. 05 7 -0 .0 19 0. 13 3 C D 0. 38 7* * 0. 42 8* * 0. 55 2* * 0. 37 0* * 0. 50 1* * 0. 40 2* * 0. 31 2* * 0. 30 1* * 0. 44 3* * 0. 26 0* 0. 65 1* * 0. 46 0* * N B -0 .0 10 -0 .0 18 0. 03 8 0. 01 6 0. 09 3 0. 00 1 -0 .1 05 0. 12 5 0. 02 4 0. 02 5 0. 18 9 0. 37 9* * 0. 22 5* W L 0. 14 3 0. 16 0 0. 00 2 -0 .1 71 -0 .0 27 0. 26 0* 0. 02 9 0. 26 1* 0. 04 7 0. 17 2 0. 42 9* * 0. 03 9 0. 31 7* * 0. 02 2 L L 0. 13 3 0. 20 8 0. 08 8 -0 .0 67 0. 04 7 0. 26 5* 0. 11 6 0. 35 5* * 0. 09 5 0. 21 0 0. 54 6* * 0. 15 9 0. 45 5* * 0. 08 9 0. 84 3* * L P 0. 18 3 0. 10 8 0. 26 6* 0. 06 1 0. 22 1* 0. 26 5* 0. 20 8 0. 23 4* 0. 27 2* 0. 10 8 0. 55 0* * 0. 09 6 0. 39 4* * 0. 06 9 0. 53 0* * 0. 64 1* * F R W 0. 42 6* * 0. 32 5* * 0. 52 4* * 0. 34 5* * 0. 55 6* * 0. 35 0* * 0. 25 8* 0. 13 4 0. 41 0* * 0. 14 9 0. 46 4* * 0. 30 8* * 0. 67 5* * 0. 14 1 0. 03 9 0. 16 8 0. 29 3* * S E W 0. 42 4* * 0. 31 8* * 0. 52 7* * 0. 33 2* * 0. 55 4* * 0. 34 4* * 0. 26 9* 0. 14 7 0. 42 7* * 0. 14 9 0. 47 3* * 0. 28 6* * 0. 66 7* * 0. 13 6 0. 04 5 0. 17 5 0. 30 7* * 0. 99 7* * P U W 0. 42 5* * 0. 33 3* * 0. 51 2* * 0. 36 3* * 0. 55 4* * 0. 35 6* * 0. 23 5* 0. 11 1 0. 37 5* * 0. 14 8 0. 44 3* * 0. 33 9* * 0. 68 0* * 0. 14 6 0. 02 7 0. 15 4 0. 26 6* 0. 99 2* * 0. 98 ** A L F :a ve ra ge le ng th of th e fr ui t, A D F :a ve ra ge di am et er of th e fr ui t, A W F :a ve ra ge w ei gh to f th e fr ui t, A W P :a ve ra ge w ei gh to f th e pu lp ,A N S :a ve ra ge nu m be r of th e se ed s pe r fr ui t, A L S :a ve ra ge le ng th of th e se ed ,A W S :a ve ra ge w id th of th e se ed ,A T S :a ve ra ge th ic kn es s of th e se ed ,S W 10 0: 10 0- se ed w ei gh t, O IL :s ee ds oi lc on te nt ,P H :p la nt he ig ht ,S D :s te m di am et er , C D :c ro w n di am et er ,N B :n um be r of m ai n br an ch es ,W L :w id th of th e le af ,L L :l en gt h of th e le af ,L P :l en gt h of th e pe ti ol e, F R W :f ru it s w ei gh tp er ac ce ss io n, S E W :s ee ds w ei gh tp er ac ce ss io n, P U W :p ul ps w ei gh tp er ac ce ss io n, * S ig ni fi ca nt ly at 5% ,* * S ig ni fi ca nt ly at 1% . Highlights in BioScience Page 8 of 11 March 2021|Volume 4 http://bioscience.highlightsin.org/ Tiendrébéogo et al., 2021 Variability and relationships between characters of physic nut (Jatropha curcas L.) Figure 3. Association of modalities of traits in the ½ plan of the multiple cor- respondence analysis (MCA) (45.41%) . BP: branching pattern, PBP: petiole base pigmentation, OIL: oil content, SW100: 100-seed weight. Discussion The agro-morphological evaluation using quantitative and qualitative characters highlighted the existence of variability for some characters. Similar results for quantitative traits were ob- tained by [20] and [11, 12]. For qualitative characters, this vari- ability relates to branching pattern and petiole base pigmenta- tion. [16] reported similar results on the petiole base pigmen- tation. However, only two types of stem branching were ob- served in this study compared to four types obtained by these same authors, thus indicating that the accessions studied are less diversified for this character. No color variation was noted on the stems and leaves of the studied accessions. These results are similar to those of [17], [21] and [22] but differ from those of [16]. Genetic correlations indicate genetic relations between characters. Knowledge of correlations among the characters is useful in designing an effective breeding program for any crops [23]. Indeed, the magnitude and direction of the genetic corre- lation is important in the choice of breeding methods and the formulation of strategies for simultaneous selection on multiple traits [2]. The correlations noted in this study corroborate those observed by [2] and [23]. In this study, statistically significant correlation of oil content existed with crown diameter and plant height. In addition, 100-seed weight character is significantly correlated with crown diameter, petiole length and plant height. These correlations are interesting for improvement programs be- cause according to [24], the selection of elite accessions to re- produce for oil extraction should be oriented towards those with the best crown and seed weight traits. Furthermore, [25] indicate that the quantity of seeds produced on the one hand is positively correlated with crown, and on the other hand the seed weight and the oil content are positively correlated. Significant and posi- tive correlations between the characters of the seeds would favor the simultaneous improvement of these characters through selec- tion. Thus, in the study, interesting correlations were noted be- tween the characters linked to the weight and dimensions of the seeds. The strong positive correlation between the characters of the seeds indicates that the genes which govern these characters are probably linked or have a pleiotropic effect. Similar results have been reported by [2] and [23] between 100-seed weight and the dimensions of the seed. However, the study found no signif- icant correlation between the oil content and the dimensions of the seeds studied. Similar results have been also reported by [2] and [18]. Furthermore, the study showed a positive and signifi- cant correlation between the 100-seed weight trait and the seed oil content trait. [26] and [23] observed a positive and significant correlation between seed weight and oil content while [27] re- vealed a negative correlation between these two characters. [18] indicated that these contrasting results could be explained by the high weight of the seed coat of some accessions. According to [16], qualitative characters are morphological markers that can be used to identify lines in a relatively short time. These au- thors reported also that the development of descriptors on peren- nial plants such as J. curcas can contribute to an effective use of germplasm in the improvement programs. Analysis of the association of characters revealed the existence of three morpho- types differing in the color of the pigmentation of the base of the petiole, the oil content of the seeds and 100-seed weight. [16] identified also three descriptors based on the pigmentation of the petiole base. For perennial plant such as J. curcas, these morphological descriptors could make it possible to select geno- types with high productive potential in the short term. Accord- ing to [23], complex plant characters such as yield are quantita- tively inherited and influenced by genetic effects, as well as by genotype and environment interaction and selection may be diffi- cult and time consuming to improve yield directly especially for perennial crops such as J. curcas. Therefore, identification and use of associations between characters are appropriate. In this study, statistically significant association of 100-seed weight ex- isted with seed oil content. Therefore, seed weight can be con- sidered as important character for early selection of seed sources. Furthermore, according to [11], the characters 100-seed weight and oil content showed the highest values of broad-sense her- itability (83.23% and 99.93% respectively) and high expected genetic advance (22.63% and 19.62% respectively). The high broad-sense heritability values associated with high expected ge- netic advance indicate that effects of the genes are of additive type for these characters and the opportunities to improve seed weight character and oil content character through the selection. Conclusion This study highlighted an important agro-morphological di- versity within the accessions of J. curcas from Burkina Faso. The variability observed within the accessions studied and the as- Highlights in BioScience Page 9 of 11 March 2021|Volume 4 http://bioscience.highlightsin.org/ Tiendrébéogo et al., 2021 Variability and relationships between characters of physic nut (Jatropha curcas L.) sociations between the characters obtained constitute a database for the genetic improvement programs of J. curcas in Burkina Faso, in particular the development of high-yielding cultivars. A positive and significant correlation between the 100-seed weight trait and the oil content trait was noted. Growth traits such as plant height and crown diameter was also significantly and positively correlated with the oil content trait. Three morpho- types were identified using petiole base pigmentation which are the green morphotype with very high oil content and high 100- seed weight, the purple morphotype with medium oil content and medium 100-seed weight and finally the brown morphotype with low oil content and low 100-seed weight. For perennial plant such as J. curcas, these results on relationships between characters could make it possible to select genotypes with high productive potential in the short term. Acknowledgments The authors gratefully acknowledge the Bioscience Labora- tory precisely Genetic and Plant Breeding Team (EGAP) of the «Université Joseph KI-ZERBO» for the financial support of this work. They are also thankful to all team members of the Bio- science Laboratory for their input in this manuscript. Authors’ Contributions This work was carried out in collaboration between both au- thors. The two first authors designed the experiment and ana- lyzed the data. Both of the authors interpreted the data, read the final manuscript, and agreed with all contents. References 1. Pandey VC, Singh K, Singh SJ, Kumar A, Singh B, Singh RP. Jatropha curcas: A potential biofuel plant for sustainable en- vironmental development. Renewable and Sustainable Energy Reviews. 2012;16(5): 2870-2883. 2. Freitas RG, Missio RF, Matos FS, Resende MDV, Dias LAS. Ge- netic evaluation of Jatropha curcas L.: an important oilseed for biodiesel production. Genetic and molecular research. 2011;10(3): 1490-1498. 3. Berchmans HJ and Hirata S. Biodiesel production from crude Jatropha curcas L. seed oil with a high content of free fatty acids. Bioresource Technology. 2008;99(6): 1716-1721. 4. Hamad B . 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Highlights in BioScience Page 11 of 11 March 2021|Volume 4 http://bioscience.highlightsin.org/ Abstract Introduction Material and methods Plant material Experimental site Experimental design Characters studied Data analysis Results Analysis of the phenotypic variability of J. curcas using qualitative variables Analysis of the phenotypic variability of J. curcas using quantitative variables Relationships between characters Discussion Conclusion Acknowledgments Authors’ Contributions References