Genetic variability, correlation and principal component analysis for agronomic traits in lentil genotypesDr. Muhammad Ejaz* and Dr. Abdul Hanan**Balochistan Agricultural Research and development center Quetta (BARDC).Corresponding Author: Dr. Muhammad EjazE-mail address: [email protected]: The research was carried out in a complete randomized block design with three replications on 15 lentil genotypes for 7 agro morphological characteristics. A wide range of divergence of plant characteristics were recorded for the lentil genotypes. The parameters (Days to 50% Flowering, Days to 50% Maturity, Plant Height, Biological Yield, Grain Yield, Harvest Index and 100 Seed Weight) showed significant differences (P ‰¤ 0.
05). The promising genotype ILL11 (918.9 Kg ha-1) and ILL8081 (847.4 Kg ha-1) produced the highest yield than the other genotypes tested. Correlation and PCA was also conducted on 15 lentil genotypes over one year for 7 characters. Harvest Index (0.807) and biological yield (0.389) showed a positive significant correlation with seed yield while a non-significant positive correlation with seed yield was recorded for plant height (0.062). A negative non-significant correlation was recorded for days to flowering (-0.
248) and days to maturity (-0.312). These three principal components (PC) accounted for 82 % of the total variation. PC1 was positive correlate with the flowering duration, days to maturity, plant height and 100 seed weight while it was negatively correlated with biological yield, seed yield and harvest index. PC2 was positively correlated with grain yield and harvest index. PC3 was positively correlated with days to flowering, harvest index and 100 seed weight. With the analysis of the agronomic characteristics over the first and second principal components, the lentil genotypes were designated into 4 different groups.Key words: genetic correlation, Lens culinaris, principal component analysis (PCA), yield componentsINTRODUCTIONThe lentil (Lens culinaris, Medik) is a leguminous, self-pollinating diploid (2n = 2x = 14) crop, domesticated earlier (Erskine, 1997). Lentil is rich in proteins, micronutrients and vitamins that are important for human diet. The vegetative part of lentil is used as a unique fodder for animals (Sarker and Erskine, 2006). Lentil is mostly cropped in rain-fed areas where the rainfall is insufficient in rotation with cereals. Lentil fixes the atmospheric nitrogen thus reduces the nitrogen requirement for other cereal crops (Fikiru et al., 2007). For meaningful breeding program, the prerequisite is the collection of germplasm and description for wide range of genetically diverse crop (Naghawi and Johansouz, 2005; Poonam et al., 2006). Several studies have been conducted on the collection and description of lentil germplasm and landraces in the world and these germplasm was used in lentil breeding programs (Fikiru et al., 2007). The international center for agricultural research in the dry areas (ICARDA) has maintained the largest and most representative collection of lentil landraces in the world (Ford et al., 2007). The lentil germplasm showing high yielding, have good root and shoot traits, drought tolerant are considered to be the valuable gene pool for the breeding program (Sarker et al., 2005). The objective of this study was to determine the genetic variability, correlation and principal component analysis for agronomic traits in lentil genotypes.MATERIALS AND METHODSThis study was conducted at Balochistan Agricultural Research & Development Centre Quetta (BARDC) during the 2017″2018 crop cycle. The research materials were comprised of 14 genotypes and 1 check improved variety (ShirAz-96). Each accession was sown by hand drill in 4 rows of 4 meter long with a 35 cm distance between them in a complete randomized block design (RCBD) with three repeats. The seed rate of 50 Kg ha-1 was used. Observations were recorded as a single mean value for each plot on days to 50% flowering (days from sowing to appearance of 50% flowers), days to 50% maturity (days from sowing to physiological maturity), plant height (cm), biological yield (Kg ha-1), grain yield (Kg ha-1) and 100 seed weight (g). Simple statistics of the means were computed using the recorded data and the observations were made as per ICARDA methods (2017). A principal component analysis (PCA) and correlation was performed for 7 traits using the Minitab-16 statistical software (give reference). Results & DiscussionThe main breeding aim of this study was to develop new cultivars that would show resistance to different biotic & A biotic stresses and would be suitable to mechanical harvesting with a high and stable yield of lentils. The collection, description and utilization of genetic resources for agronomic and morphological plant characteristics are essential steps to be taken for successful and effective breeding programs for the majority of crops (Naghavi and Johansouz, 2005). The statistical analysis of the data showed that there were significant differences (P < 0.05) (Table 1) in days to flowering (50%) among all genotypes tested. The days to flowering was ranged from 122 to 135 day, however, early flowering (122 days) was recoded in treatment 1LL46, ILL7686, ILL11 and ILL8081 that was. Late flowering (135 days) was recorded in treatment ILL438.Table-1 revealed that different lentil lines had a significant effect on days to maturity (P < 0.05). The results showed that line ILL11, ILL1196 and line ILL8081 attend maturity at short time (167, 170.5 and 171 days) while line ILL250 took maximum days to maturity (179 days). Shrestha et al 2006 reported that the high temperature and water deficits induce rapid senescence and early maturity.The effect of lentil lines was significant on plant height (Table-1). The genotypes plant height range between 25 cm (line ILL46) to 44 cm (line ILL312). Maximum plant height (44 cm) was obtained from line ILL312 which was at par with the genotypes ILL7686 (40 cm), ILL438 (37 cm), ILL465 (37.5 cm) and ILL8081 (35 cm) respectively while the minimum plant height (25 cm) was recorded in line ILL46. According to means comparison of genotype effect on biological yield (Table-1), ILL7686, ILL11, ILL250 fashioned the highest biological yield (3571 Kg ha-1) and ILL312 produced the lowest one that was 2784.3 Kg ha-1. Significant increase in yield was recorded in genotype ILL11 (918.9 Kg ha-1) which was at par with the genotype ILL8081 (847.4 Kg ha-1), ILL648 (845.5 Kg ha-1), ILL7686 (824.3 Kg ha-1), ILL1196 (824.1 Kg ha-1) and ShirAz-96 (774.4 Kg ha-1) respectively (Table-2). The lowest yield was recorded in genotype ILL254 that was 586.6 Kg ha-1 (Figure-3). Shrestha et al., 2005 reported that the lentil race obtained from cross between South and West Asian lines have rapid canopy cover, early phenology and high harvest index as result increase dry matter production and harvest index.Higher economical yield percentage (Table-2) was observed in treatment ILL648 (28.17 %) statistically similar yield was observed in genotype ILL8081 (27.19%), ILL1196 (26.58%), ILL11 (25.73%), ShirAz-96 (23.31 %) and ILL7686 (23.08%) respectively. ILL250 with grain yield of 17.24% significantly produced the lowest economical yield percentage.The 100-seed weight (Table-2) ranged from 4.23g to 2.36g and found significant differences among the treatment means. Treatment ILL1399 significantly produced higher 100 seed weight (4.23g) and lower seed weight was observed in treatment ILL7686 (2.36g). Joshi et al 2005 tested 110 native and exotic lines of lentil for various traits and reported that the 100 seed weight ranged between 1.1g to 7.2g.Highly significant correlation (Table-3) was recorded between grain yield and harvest index which was 0.874 on the other hand non-significant negative correlation was noted between biological yield and harvest index (-0.227). Correlation was detected with plant height (0.1093) and days to maturity (0.0796). On contrary, biological yield per plant exhibited negative but non-significant association with number of seeds per pod (-0.0752), days to 50% flowering (-0.0233). Bhattacharya et al. (2004) tested 14 advanced lentil genotypes under irrigated condition and described that economical yield had resilient positive correlation with harvest index. Joshi et al (2005) conducted experiment on 110 indigenous and exotic lines of lentil for various yield components and reported that days to flowering and maturity and 100 seed weight showed negative correlation with economical yield. Karadavut (2009) explored associations between yield and yield components by using a correlation in a population of 24 small seeded lentil varieties, positive and significant correlations were found between the yield and harvest index. The genetic parameter were investigated in 25 genotypes of lentil, seed yield was positively correlated with harvest index (Tyagi and Khan 2010). Harvest index was strongly correlated with grain yield (r=0.8072) which is agree with Dutta and Mondal (1998). This character could be a good index for selecting high yield genotypes in normal condition. The correlation coefficient of days to flowering with days to maturity (r=0.4474) and grain yield with biological yield was significant and positive (Table 3). The contribution of the agronomic characteristics in the principal component and scatter diagrams for the first 2 principal components are shown in Table 4 and Figure 1. The first 3 principal components explain the 82.7% of total variance. Principal 1, which is the most important component, accounts for 44.7% of the total variation and is positively related to the days to flowering , days to maturity , plant height and 100 seed weight. Principal 2 accounted for 71.2% of the total variation and the main characteristics of this component were positively correlated to the days to flowering, days to maturity, plant height, grain yield and harvest index but negatively associated with biological yield and 100 seed weight. Principal 3 accounted for 82.7% of the total variation and were positively related to the days to flowering, harvest index and 100 seed weight. Figure 2 show that the first and second PCA components allow the lentil landraces 4 groups for the researched traits. Asghar et al. (2010) tested 30 lentil genotypes to investigated genetic diversity and distributed 10 distinct groups a desirability index was constructed to evaluate the worth of particular genotypes for different traits. Table No. 1: Mean performance of agronomic traits of lentil genotypes.Sr.# Genotypes Days to flowering (50%) Days to Maturity (50%) Plant height (cm) Biological yield (Kg ha-1)1. ILL1196 128bcde 170.5ef 28cdef 3125ab2. 1LL46 122e 172cde 25f 3350ab3. ILL262 128bcde 172cde 25.5ef 3420ab4. ILL254 123de 174.5abcde 27.5def 3126.5ab5. ILL1399 129.5abcd 176.5abc 34.5abcdef 3337.7ab6. ILL7686 122e 176abcde 40ab 3571.4a7. ILL648 130abc 175abcde 34bcdef 3001ab8. ILL11 122e 167f 29cdef 3571.4a9. ILL465 134a 177ab 37.5abc 3007ab10. ILL312 134a 175.5abcd 44a 2784.3b11. ILL438 135a 176.5abc 37abcd 2911.8ab12. ILL45 126cde 174bcde 32.5bcdef 3040.3ab13. ILL250 133abc 179a 35abcde 3571.4a14. ILL8081 122e 171.5def 35abcde 3125ab15. ShirAz-96 127cde 174bcde 30cdef 3286.5abLSD value 6.98 4.92 9.81 768.19Values within the same column followed by the same letters are not significantly different, using LSD Range Test at 5% level.Table No.2: Mean performance of agronomic traits of lentil genotypes.Sr.# Genotypes Grain yield(Kg ha-1) Harvest Index (%) 100 Seed weight (g)1. ILL1196 824.1abcd 26.58ab 2.94ab2. 1LL46 650.2bcde 19.38cd 2.91ab3. ILL262 611.9cde 17.84cd 3.04ab4. ILL254 586.6e 18.89cd 3.91ab5. ILL1399 654.5bcde 19.77cd 4.23a6. ILL7686 824.3abcd 23.08abcd 2.36b7. ILL648 845.5abc 28.17a 3.53ab8. ILL11 918.9a 25.73ab 3.08ab9. ILL465 659.0bcde 21.89bcd 2.74ab10. ILL312 613.5bcde 22.06bcd 3.21ab11. ILL438 626.5bcde 21.72cd 3.31ab12. ILL45 590.9de 19.5cd 3.17ab13. ILL250 616.0bcde 17.24d 3.85ab14. ILL8081 847.4a 27.19ab 2.67ab15. ShirAz-96 774.4abcde 23.31abc 2.58abLSD value 234.1 5.88 1.79Values within the same column followed by the same letters are not significantly different, using LSD Range Test at 5% level.Table-3: Estimate of simple correlation coefficients between different characters in lentil genotypes DF DM PH HI BY GYDM 0.4474*PH 0.2868ns 0.2891nsHI -0.0219ns -0.3370ns 0.0880nsBY -0.3654* 0.0047ns -0.0063ns -0.2226nsGY -0.2488ns -0.3125ns 0.0625ns 0.8072** 0.3894*HSW 0.0770ns 0.3020ns -0.2370ns -0.1455ns 0.0048ns -0.1398ns*, ns, Significant and non-significant at 5 % probability level, respectivelyFigure No.1 Scatter diagram of lentil genotypes and agronomic traits. DF days to flowering (50%), DM days to maturity (50%), PH plant height (cm), BY biological yield (Kg ha-1), GY grain yield (Kg ha-1), HI harvest index (%), and HSW 100 seed weight (g)Figure No.2 Graphic representation of the behavior of 15 line of lentil according to first two principal components and identification of clustersFigure 3. Graph between lentil genotypes and grain Yield Kg ha-1 Table No. 4: Principal component analysis, eigenvalue, percent of variation accounted for first three principal components (Pcs).Character Principal 1 Principal 2 Principal 3Eigen value 3.127 1.857 0.803Proportion of variance (%) 44.7 26.5 11.5Cumulative variance (%) 44.7 71.2 82.7Days to flowering (50%) 0.448 0.280 0.081Days to maturity (50%) 0.491 0.096 -0.371Plant height 0.256 0.513 -0.496Biological Yield -0.239 -0.445 -0.673Grain Yield -0.465 0.311 -0.157Harvest Index -0.342 0.537 0.182100 seed weigh 0.321 -0.256 0.315