Use of Broad Based Populations for Expoiting Heterotic Group in Cotton Gossypium hirsutum L

Abstract

In the present study for the first time four elite combiners from each heterotic newlinegroup were used to create variability with a view that four parents were used would be newlinedifferent in dominant favorable allele and it will be possible to recombine these newlinefavorable alleles to creating greater variability for combining ability. By keeping this newlineidea broad-based population was developed from each heterotic group. Heterotic boxes newlinewere formed by using double cross (four parents based) F1s (GCOT 16 × GJHV 358) × newline(RCR 109 × RCR 102) on the stay green group side and (RGR 2572 × RGR 30) × newline(RGR 46 × RCR 4) on high RGR group side. In an earlier study, the double-cross F1s newline(DCF1 newline) of both the heterotic groups was raised in kharif 2015. Thirty-eight random newlineDCF1s were picked from each of the SG and high RGR groups and evaluated. The newlinepresent study on reciprocal selection for combining ability was initiated with these 38 newlineDCF2 newlinelines of SG group crossed with three reciprocal RGR parents RGR 30, RGR 46, newlineRCR 4 and one additional RGR tester (Surabhi). Conversely, the 38 DCF2 lines of the newlinehigh RGR group were crossed with three reciprocal SG parents GCOT 16, GJHV 358, newlineRCR 102 and one additional SG tester (SM). Two set of these crosses were subjected to newlineline × tester analysis (152 + 152 crosses). To assess and compare recombinational newlinevariability for combining ability and to assess the potentiality of derived F1s based on newlinethese new DCF2 newlinelines, respective benchmark crosses were developed by crossing the newlineparental lines of SG and high RGR heterotic group. These derived F1s of double cross newlineF2 newline lines were compared with commercial checks and bench mark crosses. Based on this, newlinemagnitude of variability for combining ability and transgressive segregation for newlinecombining ability was assessed. newline