Study of Genetic Architecture on yield and Some of the Yield Components in Lentil (Lens Culinaris Medic.)

Abstract

Inheritance of the yield and yield contributing characters of six lines of lentil (Lens culinaris Medic.) was studied in 2005-2009 through diallel, combining ability, heterosis and model fitting in the first part (Part I) consisting of two experiments. Twelve yield contributing characters viz., days to flower (DF), plant height at first flower (PHFF), number of primary branches at first flower (NPBFF), number of secondary branches at first flower (NSBFF), canopy area at maximum flower (CAMF), number of secondary branches at maximum flower (NSBMF), number of pods per plant (NPdPP), pod weight per plant (PdWPP), number of seeds per plant (NSPP), seed weight per plant (SWPP), individual plant weight (IPlW) and root weight (RW) were studied in a six parental half diallel analysis in experiment I. In experiment II, above characters were considered for study of heterosis and model fitting. The combining ability analysis in lentil showed that the variation due to gca was found to be significant for the characters namedly DF, PHFF, CAMF and RW and variance due to sea was non significant for all of the characters. Component variance due to gca (clg) was higher than that of due to sea (cr2s) for DF, NPBFF, CAMF, PdWPP, SWPP and IPlW. Additive genetic component (cr2A) was greater than dominance component (cr2D) for DF, PHFF, NPBFF, CAMF, PdWPP, SWPP, IPIW and RW. From the comparison of gca effects of individual parents for twelve characters, positive significant gca effect was seen for DF by P 4, for PHFF by P2 and P3, for NSBFF by P 4, for CAMF by P2 and P3, for IPlW by P2 and for R W by P2 and P4. The negative and significant gca effect was obtained for DF by P3, for PHFF by P1 and for NPBFF, CAMF, NPdPP, PdWPP, NSPP, SWPP, IPlW and RW by P6 in experiment I. P4 for NSBFF, NPdPP, NSPP and RW, P2 for PHFF, CAMF, PdWPP SWPP and IPlW, P5 for NPBFF and NSBMF and P3 for DF performed as better combiner. P 1 xP2 performed good specific combiner for NSBFF, Pd WPP, SWPP and RW and P1 xP3 for CAMF, NSBMF, NPdPP and IPIW. In the present study, the ratios of [(H1/D)] 112 suggested over dominance for NSBFF, NSPP, SWPP, IPIW and RW, whereas partial dominance was recorded for the remaining characters except NPBFF, NPdPP and PdWPP in F1 generation. In F2 generation over dominance was found for DF, NPBFF, NSBFF, NSBMF, NPdPP, NSPP and SWPP, whereas partial dominance was shown by PHFF, CAMF, IPIW and RW. Only one group of genes controlled the characters namedly DF, NPBFF, NSBFF, CAMF, NSBMF, NPdPP, PdWPP, NSPP, SWPP, IPIW and RW and two group of genes controlled PHFF in F1 generation, whereas in F2 generation one group of genes controlled the characters viz. DF, PHFF, NSBFF; six groups of genes controlled the character NPBFF; four groups of genes controlled the characters viz., CAMF and NSBMF; three groups of genes controlled NPdPP; two groups of genes controlled PdWPP, NSPP and SWPP; ten groups of genes controlled IPlW and seven groups of genes controlled RW. From graphical analysis, it was evident that array 1 possessed dominant gene in excess for PHFF of replication 2, for CAMF of replication 2 and for IPlW of replication 2 in F 1 generation. Array 2 possessed dominant gene in excess for R W of replication 2, for DF and for NSPP of replication total in F 1 generation and this array possessed dominant gene in excess for NPBFF of replication 2, for NSBFF of replication 1, for PdWPP of replication 2, for NPBFF, NPdPP and PdWPP of replication total in F2 generation. Array 3 possessed dominant gene in excess for NSBMF of replication 2 and for NPdPP of replication 2 in FI generation and for NPdPP of replication 1, for SWPP of replication 1 and for SWPP of replication 1 in F2 generation. Array 4 possessed dominant gene in excess for NSPP of replication 1, for PHFF, NSBMF and NPdPP of replication total in FI generation and for NPBFF of replication 1, for CAMF of replication 2 and for IPlW in F2 generation. Array 5 possessed dominant gene in excess for CAMF of replication 1, for NPdPP of replication 1, for IPlW of replication 1, for NPBFF, CAMF and IPlW of replication total in F1 generation and for NSBMF of replication 2, for NSPP of replication 1, for SWPP of replication 2, for IPlW of replication 1, for RW of replication 1, for NSPP, SWPP and RW ofreplication total in F 2 generation. Array 6 possessed dominant gene in excess for PHFF of replication 1, for NPBFF of replication 1, for NSBMF replication 1, for NSPP of replication 2, for PdWPP and SWPP in F1 generation and for PHFF of replication 1, for PHFF of replication 2, for CAMF of replication 1, for PHFF and CAMF of replication total in F2 generation. Array 1 possessed recessive gene in excess for PHFF of replication 1, for CAMF of replication 1, for NSBMF of replication 1, for NPdPP of replication 1, for NPdPP of replication 2, for NSPP of replication 1, for IPl W of replication 1, for PHFF, CAMF, NSBMF, NPdPP, PdWPP, SWPP and IPlW of replication total in F, generation. Array 1 possessed recessive gene in excess for NPBFF of replication 1, for CAMF of replication 2, for Pd WPP ofreplication 2, for NSPP ofreplication 1, for SWPP ofreplication 1, for SWPP ofreplication 2, for NPdPP, PdWPP, NSPP, SWPP and IPlW of replication total in F2 generation. Array 2 possessed recessive gene in excess for NPBFF of replication 1 and for NSPP of replication 2 in FI generation and for PHFF of replication 1, for PHFF of replication 2, for IPlW of replication 1, for PHFF and CAMF of replication total in F2 generation. Array 3 possessed recessive gene in excess for DF and NSPP of replication total in FI generation. This array possessed excess of recessive genes for NPBFF of replication 2, for CAMF of replication 1, for NSBMF of replication 2 and for NPBFF of replication total in F2 generation. Array 4 possessed recessive gene in excess for PHFF of replication 2, for CAMF of replication 2, for IPlW of replication 2 and for RW of replication 2 in F1 generation. This array possessed recessive in excess for NSBFF of replication 1, for RW of replication 1 and for RW of replication total in F2 generation. Array 5 possessed recessive gene in excess for NSBMF of replication 2 in FI generation. Array 6 possessed recessive gene in excess for NPBFF in FI generation and for NPdPP of replication 1 in F2 generation. Array 3 possessed more or less equal proportion of dominant and recessive genes for most of the characters in both generations. In heterosis study, P1 xP2 showed the highest value of mid parent and better parent heterosis for NSBFF, PdWPP, SWPP and RW. From joint scaling test, it was revealed that non significant x2 value was obtained by all of the crosses for SWPP. From the inheritance study through diallel and heterosis, it was found that P1 xP2 and P1 xP3 was the promising crosses in respect of PdWPP, SWPP and RW. These crosses appeared important for heterosis study. In second part (Part-II) of the present investigation, FI materials of half diallel crosses for nine characters viz., days to flower (DF), plant height at first flower (PHFF), number of primary branches at first flower (NPBFF), number of secondary branches at first flower (NSBFF), canopy area at maximum flower (CAMF), pod weight per plant (PdWPP), seed weight per plant (SWPP), individual plant weight (IPlW) and root weight (RW) were studied for correlation, path-coefficient and selection index. Phenotypic component of variation ( cr2p) was higher than genotypic (cr2g) component of variation. The highest genotypic and phenotypic components of variations were obtained for CAMF. In the present materials, high genotypic values caused high phenotypic values. In this investigation, genotypic correlations were higher than the respective phenotypic correlations for most of the characters. SWPP showed highly significant and positive correlation co efficient with other characters except NPBFF at genotypic level and except NPBFF and DF at phenotypic level. The highest significant and positive genotypic correlation coefficient was recorded for NSBFF with PdWPP at genotypic level and PdWPP with SWPP at phenotypic level. PdWPP had the highest positive direct effect on SWPP at both genotypic and phenotypic level. The maximum expected genetic gain of 4603 .196% was found when NPBFF and R W were included in the discriminant function. These two characters had high correlation coefficient with most of the characters studied as well as direct effect at genotypic level may be considered as primary yield components.