Exploitation of Broad Based Heterotic Populations for Improving Hybrid Performance in Cotton Gossypium hirsutum L

Abstract

In the present study an attempt was made to follow reciprocal selection for newlinecombining ability for exploiting the opposite heterotic groups by forming heterotic newlineboxes using double cross F1s (SG 102 X SG 109) X (SG 16 X SG 358) on Stay Green newlinegroup side and (RGR 2572 X RGR 30) X (RGR 46 X RCR 4) on High RGR group side. newlineThese double cross F1s were advanced to F3 generation, where 20 double cross F3 lines newlineeach from opposite groups were used for practicing reciprocal selection for improving newlinetheir ability to combine with opposite group testers. The double cross F3 lines of Stay newlineGreen group were crossed with two reciprocal testers RGR 2572 and RCR 4 and an newlineadditional tester RB2F2- 15 and the double cross F3 lines of High RGR group with two newlinereciprocal testers SG 102 and SG 109 and an additional tester SSG2, producing 60 newlinederived F1s each from opposite groups. These derived F1s of double cross F3 lines were newlinecompared with commercial checks and bench mark crosses. Based on this, magnitude of newlinevariability for combining ability and transgressive segregation for combining ability newlinewas assessed. In the second part of the study, out of twenty double cross F3 lines, ten newlinelines were selected from each group, agreeably on the basis of above average newlineperformance. The selected ten Stay green lines were crossed to selected ten High RGR newlinelines in a line x tester fashion producing hundred derived F1s. Here an attempt was newlinemade to relate the combining ability status of lines against reciprocal testers and the newlineperformance of their crosses in 10 × 10 set of derived F1s. The results indicated that newlinechances of getting superior hybrids are high when crosses are made between selected newlinegood combiner lines of opposite groups. newline