Evaluation of Genetic Nature and Selection Index Study of Yield and Yield Components in Irradiated Lines of Lentil (Lens Culinaris Medic)

Abstract

The whole work of the present investigation was carried out under two separate parts, such as triple test cross and correlation, path-coefficient and selection index. Under two parts the eight yield and yield contributing characters of ientil (Lens culinaris Medic.) studied, were plant height at first flowering (PJ;IFF), number of branches per plant at maximum flowering (NBPiv1F), plant area per plant (PAPP), plant weight per plant (PWPP), number of pods per plant (NPdPP), pod weight per plant (PdWPP), number of seeds per plant (NSPP) and seed weight per plant (SWPP). In part-I, triple test cross were studied in ten crosses. In the analysis of variance the total epistasis and partitioning of the total epistasis into i (additive x additive), j (additive x dominance) and I type (dominance x dominance) epistasis were found to be non significant in almost all of the crosses for all the characters except PHFF ( cross 3 and cross 9). So, in the absence of epistasis L1, L2 and L3 testers are adequate and the estimation of additive (D) and dominance (H) components were calculated. Both the additive and dominance components were found to be highly significant in all the crosses for all the characters. So, both additive and dominance gene action were observed to be equally important for all the characters in the present work. Regarding the degree of dominance all the three types viz., over, complete and partial dominance were found to be present. The negative and significant correlation between sums and differences was observed in cross 4 (-0.744*) for PHPP, in cross 6 (-0.8015**) for NPdPP, in cross 3 (- 0.6556*) for PdWPP and in cross 3 (-0.7229*) for SWPP. All other crosses with their respective characters showed non-significant correlation. Both broad sense and narrow sense heritability estimates were found to be low to high in all the crosses for all the characters. The cross 7(Bml-20kr x Lll- 30kr) for seed yield and yield components followed by cross 8 (Bm4-30kr x Bm3) and cross 5(Bml-25kr x Ll 1-30kr) for some of the yield components may be selected for further breeding research, as they showed moderate to high heritability, additive-dominance inheritance and non-significant epistasis. In part H, correlation, path-coefficient and selection index of thirteen parental lines were investigated. The lines were genetically well differentiated as indicated by the analysis of variance. The character PAPP, 2 NSPP and NP.dPP showed the highest values for <ip11, cr2811, cr2 LR11, and crw11 components of variation which indicated better scope for improvement of these characters through selection. The characters PWPP, NPdPP, Pd WPP and NSPP showed significant and positive correlation with SWPP at both phenotypic and genotypic levels. The. characters PAPP, PWPP, PdWPP and NSPP exhibited positive direct effect at phenotypic level and PHFF, NBPMF, NPdPP and NSPP had positive direct effect at genotypic level on SWPP. The character NSPP also exhibited positive direct effect on SWPP both at phenotypic and genotypic levels. The character PdWPP had the highest positive direct effect (0.4602) followed by PWPP and NSPP at phenotypic level and NPdPP had the highest positive direct effect ( 1.9731) followed by NSPP and NBPMF at genotypic level on SWPP. In the discriminant function analysis, when individual character was judged separately the highest and positive expected genetic gain was found for SWPP followed by PWPP and PHFF. The highest expected genetic gain were obtained for three characters combination viz., NBPMF + PWPP + SWPP ( 99.5590%) followed by two characters combinations for PWPP + SWPP (98.1252%) and for NBPMF + SWPP (91.4552%). To make the selection breeding programme effective major emphasis should be given on PWPP and also on PHFF and NBPMF as these are also appeared to be primary yield components. So, during selection NPdPP, PdWPP and NSPP also be considered because they showed significant positive correlation and positive direct effect on yield.