Punia, M.S.Aggarwal, Madhu2017-06-032017-06-032015http://krishikosh.egranth.ac.in/handle/1/5810014968The present investigation comprised of two experiments. The first experimental material consisted of six generations i.e. parents (P1 and P2), F1, F2 and back crosses (BC1 and BC2) of six crosses namely, Varuna x Bio-YSR; Rohini x Bio-YSR; RH-8812 x Bio-YSR; Varuna x JMMWR-9348; Rohini x JMMWR-9348 and RH-8812 x JMMWR-9348 to study the inheritance of white rust resistance and genetics of quantitative traits including seed yield and its component characters as well as to investigate the association of white rust resistance with molecular markers. The second experiment was carried out in Line x Tester mating design conducted to study the GCA and SCA effects of parents and crosses, respectively along with heterosis of the resulted hybrids. Both the experiments were conducted in the Department of Genetics and Plant Breeding, CCS Haryana Agricultural University (CCSHAU), Hisar, India during two successive years of Rabi seasons 2012-13 and 2013-14. The results have shown that inheritance of white rust resistance was governed by a single dominant gene which was also confirmed by SSR marker analysis. It has been observed that there was a strong association between field results for inheritance of white rust and SSR marker studied. Generation mean analysis revealed significant differences for all traits studied. The A, B, C and D individual scales were also significant for most of the characters indicating thereby the presence of non-allelic interactions. Additive component was significant for most of the characters and even as preponderant in magnitude over the dominance component. Either all or any of the three types of epistatic interactions (i, j and l) were significant for most of the cases and generally it was the “i" type of interaction which is more frequently prevailing for most of the traits studied over the crosses. However, the magnitude and direction of estimates changed from cross to cross. Additive x additive (i) type of interaction was reported for days to flowering, days to maturity, plant height (cm), number of primary branches per plant, number of secondary branches per plant, siliqua length (cm), number of seeds per siliqua and oil content (%). Duplicate type of interaction was apparent for days to flowering, days to maturity, plant height (cm), number of primary branches per plant, number of secondary branches per plant, siliqua length (cm), number of seeds per siliqua and oil content (%). Complementary type of interaction was also recorded for 1000 seed weight. The GCA effects indicated that among females, RH-1120 was a good general combiner for number of primary branches per plant, seed yield per plant (g) and 1000 seed weight (g); RH-1155 for number of primary branches per plant, main shoot length (cm) and siliqua length (cm). Among the males, Bio-YSR was found to be a good general combiner for plant height, number of secondary branches per plant and 1000 seed weight (g); JM-1 for days to flowering , seeds per siliqua and seed yield per plant (g). On the basis of SCA effects, 5 crosses namely, RH-0845 x Bio-YSR; RH-1155 x JM-1; RH-1139 x JMMWR-9348; RH-1152 x JM-1 and Kranti x JMMWR-9348 were found to be good for seed yield per plant (g). Significant heterosis was observed for plant height (cm), main shoot length (cm), number of siliquae on main shoot, siliqua length (cm), days to flowering, days to maturity and seed yield per plant (g). The contribution of lines was in general more than testers toward total variance for every character except for days to maturity and number of secondary branches per plant. SCA variances were higher than GCA variances which indicated that one can go for hybrid breeding programmeenGene effects, Generation mean analysis, White rust, SSR markers, Indian mustardThesis