Pant, UshaMeena, Jitendra Kumar2018-10-202018-10-202013-06http://krishikosh.egranth.ac.in/handle/1/5810081781The present investigation was carried out with the aim to evaluate the genetic purity of cross combinations using SDS-PAGE analysis and study of selection parameters, combining ability, extent of heterosis for various quantitative characters in Brassica juncea (L.) Czern & Coss. The experimental material for present study comprised of a set of 15 genotypes of Indian mustard (Brassica juncea L.) of diverse origin involving four early maturing genotypes (NDRE-4, PRE-2007-6, PR-2006-1 and PRE-2009-9), six agronomically superior genotypes (NDYR-8, Kranti, Maya, Bhaghirathi, RGN-74 and RGN-145), two genotypes suitable for late sowing (Vardan and Ashirwad) and three bold seeded genotypes (PRB-2006-5, PRB-2008-5 and PRB-2004-3-4). Crosses were made between these genotypes in all possible combinations excluding reciprocals during rabi 2011-12. The parents and their 105 F1’s along with one standard variety (Kranti) were evaluated in a randomized block design with three replications during rabi 2012-13 at Norman E. Borlaug Crop Research Centre, G.B. Pant University of Agriculture and Technology, Pantnagar. The combining ability analysis was performed by following Griffing’s (1956) method 2 and model 1. Results of ANOVA showed that the mean squares due to gca and sca were highly significant for all the characters except secondary branches per plant, the magnitude of former being higher than later, indicating predominance of additive gene action for the expression of the characters under study. The estimates of 2 sca were found to be higher than the 2 gca for all characters except number of seeds per siliqua and oil content. Predictability ratio was highest for days to 50 percent flowering, number of seeds per siliqua and oil content. It indicated the predominance of fixable variance which can be utilized by following any breeding methodology for improvement of such traits. For rest of the traits the value of predictability was lower than one. It represented the involvement of non-fixible variance so in such characters the heterosis breeding appears to be the best option. Average degree of dominance showed partial dominance(<1.0) for days to 50% flowering, number of seeds per siliqua and oil content and over dominance(>1.0) for primary branches per plant, glucosinolate content, chlorophyll content, siliqua length, length of main raceme, test weight, siliquae on main raceme, secondary branches per plant, seed yield per plant, plant height, days to maturity and siliqua density. Based on significant GCA effects in desirable direction, the parents NDRE-4 (-3.651**) for early maturity; NDRE-4 (-11.077**) for dwarf plant height; Maya (1.796**) for seed yield per plant; NDYR-8 (0.736**), for oil content and Kranti (-7.104**) for low glucosinolate content could be screened as superior donors. The study revealed that crosses Bhaghirathi × PRB-2004-3-4 (-6.252**) for early maturity; PRB-2008-5 × PRB- 2004-3-4 (-30.236**) for dwarf plant height; Vardan × Ashirwad (0.849*) for oil content and Bhaghirathi × RGN-145 (-36.632**) for low glucosinolat content had high magnitude of sca effects. The evaluation of heterosis revealed that heterotic combinations PRB-2004-3-4×PRE-2009-9 (-9.627**), Bhaghirathi × PRE-2009-9 (-16.53**), RGN-145 × PR-2006-1 (-4.64**) for early maturity; PRB-2008-5 ×PRB-2004-3-4 (-24.37**), PRB-2008-5 × PRE-2009-9 (-24.89**), PRE-2009-9 × NDYR-8 (-23.32**) for dwarf plant height; PR-2006-1 × NDRE-4 (201.74**) , PR-2006-1 × NDYR-8 (137.26**), Maya × PRE-2004-3-4 (40.26**) for seed yield; PRE-2009-9 × NDYR-8 (15.84**), RGN-74 × PRE-2007-6 (2.91**), Maya × NDYR-8 (2.09**) for oil content had highest potential for of mid parent heterosis better parent and economic heterosis respectively. SDS-PAGE Electrophoresis was employed to assess the genetic purity of parents and their 105 F1’s. Based on protein profiling, 105 F1’s and 15 parents were characterized by soluble leaf proteins separated on SDS-PAGE. A wide variation was observed in the pattern of protein bands of studied hybrids and parental lines. The hybrids differed in the number of bands, their relative mobility and intensity. In case of hybrids the bands at different rf values distinguished the F1’s from their parental lines. The bands in F1’s at different rf value may be inherited from one or both parents or may be new bands present with different intensity.ennullThesis