COMBINING ABILITY AND GENE ACTION FOR YIELD AND YIELD CONTRIBUTING CHARACTERS IN INDIAN MUSTARD (Brassica Juncea L.)

Abstract

A 8 x 8 diallel experiment (excluding reciprocal) on Indian mustznd (Brass/cc, /wzcca I ..) was cundtieted to study the nature and magnitude Of gene actioii and corn bluing ability aiia lvsis and inheritancc Rn seed yield and oil icr related ciiaracter such as days to 500/u flowering, days to niaturit . plant height, primarN branches per plant. secondary branches per plant. length of siliqua. siliquac per plant. seeds per siliqua, 1000-seed weight, seed Nicld per plant. harvest index and oil content. There were significant variations among the e nolypes fbi all I he characters sitidied. The corn ponents of' variance for general corn bi tmg aN lit3 ( gca ) and sped lie combining abi I icy (sea) were Ii igh lv sign i [leant lbr at I Ira its indicating the role of heidi additive and non-additive corn ponents in the genetic system of these characters. 1 he inheritance of secondary branches per plant, length of si I iqtia. si! iqi ac per plant and seed yield per plant was control led In non-akl itive type of gene action. 'I he parental genotype Dl I-IS (F'i) and DH- II (I) were the best general combiners Rn seed ) ield. The parents BA Rlsar- 10 (I'j. h)atilat (114 ) and Jun-536 ( P,) were desirable 11w earliness and dtriiiess. t3otti parents BAkIsar- tO (l') and BAR Isar- I I (Ps) were lou RI su itabk for dwarf plant type and higher number of si I i(Iuae per plant. The yellow seeded parental genotype ILl-I I (P0) was found to be the best general combiner for primary branches per plant. seeds per siliqua and oil content. ftc cross l3ARlsar-I0 x 13J-I I (C1) and DI 1-18 x BARIsar-ID ((.'1 ) were the best specific combiners for early maturity and dwarfness. The cross 1)11-18 s Jtni-536 iv BARisar- 10 x BJ- 17 (Cl.)) and BARIsar- 10 x l)aulat (CO were ibund best ibr seed yield per plant and siliqtiac per plant. Majority oldie crosses showed high sea elicets for seed yield involving high x low, low x low and high x high gc;i parents. Vr-Wr analysis relating to graplucal presentaLion of niajor genetic leatures was done for all the twelve characters. Over Join inanee was observed lbr primary branches per plant, secondary branches per plant, length of siliqua. si liquac per plant. seeds per siliqua, seed yield per plant and harvest index. While part ia I domu i nam ice s as recorded tor days to 50% flowering. days to maturity, plant height. 1000-seed weight and oil content. Component of variation and various genetic parameters such as degree of do))) inance. doni inance ratio, narrow sense heritability etc. were estimated. Results showed that positive and negative alleles were in unequal proportion among the parents for all characters. Dominant gene action was predomni ia:it iii most of the traits except days to 50% liowering. plant height. secondary branches per plant. 1000-seed weight and harvest index. Dominance and recessive genes were Ltncquall) distributed in the parents for all characters. Iligh narrow sense heritability was observed lbr days to niaturity. plant height and I 000-seed weight. v