Estimation of gene effects for seed yield its component traits and inheritance study in brassica rapa var yellow sarson

Abstract

Rapeseed-mustard is the second most important edible oilseed crop in India. Yellow Sarson newline(Brassica rapavar. Yellow Sarson) have best oil quality among the three sub- species of B. rapai.e. Yellow newlineSarson, Brown Sarson and Toria. The present investigation was thus conducted to find out the inheritance newlinepattern and estimates of gene action for some important characters in Brassica rapa var. Yellow Sarson. The newlinefour different crosses namely YSH-0401x Pant Sweta, Pant Sweta x Apetalous, PYS-2017-6 x PPS-1 and newlineNDYS107 x B9 were attempted to study inheritance of flower colour, flower petalous condition, siliqua newlineposition and ovary locules respectively. The six generation (P1, P2, F1, F2, and BC1, BC2,) of 4 different crosses newlineviz., was grown during the rabi season of year 2021-2022 at NEBCRC, Pantnagar to generate data for newlineinheritance study. The data of different generation were subjected to chi-square analysis to test the goodness of newlinefit for the appropriate genetic ratios in crosses. The results of study revealed that all four characters were under newlinemonogenic control. In case of petal colour the yellow petal colour is dominant over the white petal colour, newlinepetalous flower condition is dominant over apetalous condition, upright siliqua orientation was domianat over newlineinverted siliqua orientation, multilocular ovary was dominant overbilocular ovary. For estimation of nature and newlinemagnitude of gene action for seed related traits an experiment was carried out at laboratory of Breeder Seed newlineproduction Centre, G.B. Pant University of Agriculture and Technology Pantnagar, Uttarakhand. The six newlinegeneration (P1, P2, F1, F2, and BC1, BC2,) of 4 crosses used in experiment first was grown in CRD design in newlinelaboratory to generate data for generation mean analysis. Observations were recorded for characters namely newlinegermination percent, seedling length (cm), root length (cm), fresh weight (g), dry weight (g), seed vigour index newlineI and II. The results of scaling tests indicated the presence of epistasis in all four crosses. In general duplicate newlineepistasis was found to be more prominent as compared to complementary epistasis for all the studied traits. newlineThe presence of duplicate gene interaction indicated that selection should be delayed for later generations till newlinefixation and accumulation of favourable genes. The six generation (P1, P2, F1, F2, and BC1, BC2,) of 4 different newlinecrosses used in experiment I and II was grown during the rabi season of year 2020-2021 to generate data for newlinegeneration mean analysis for seed yield its components and quality traits.Observations were recorded for newlinedifferent traits viz., days to maturity, number of primary branches per plant, height of raceme (cm), number of newlinesiliqua per plant, length of siliqua (cm), number of seeds per siliqua, thousand seed weight (g), seed yield per newlineplant (g), protein content (%), oil content (%), erucic acid (%) and glucosinolet content (and#956;mole/g). The results newlineof scaling tests revealed that epstatis was present in all crosses for all characters. Although both additive and newlinenon-additive gene action were present in all studied characters but in general the magnitude of dominance was newlinefound to be more as compared to additive gene action which indicated the possibility of exploitation of newlineheterosis in these crosses. newline