Assessment of genetic variability for root traits in recombinant inbred lines of tetraploid cotton (Gossypium Spp.)

Abstract

Dharwad Hirsutum Barbadense Recombinant Inbred Lines (DHBR lines) derived from cross between G.hirsutum var.DS-28 and G. barbadense var.SBYF-425 were under evaluation for seed cotton yield (kg/ha), yield contributing and fiber quality traits under assured rain fed condition at Agriculture Research Station, Dharwad during 2012-13 in the process of QTL mapping. But this testing year became adverse as it received 33.35 % (549 mm) less rainfall as against 823.78 mm of last twenty one years. Therefore, we recorded observations on root traits related to moisture stress tolerance. Presence of significant difference between DHBR lines for root traits indicates the presence of variability for these traits under moisture stress conditions. Moderate to high heritability observed for root traits. As genotypes with longer primary roots are expected to be moisture stress tolerant, six genotypes viz., DHBR- 170 (31.0 cm), 87 (28.50 cm), 96 (28.50 cm), 44, 111 (28.0 cm) and 145 (28.0 cm) recorded significantly higher primary root lengths than superior check; MCU-5 and SBYF-425 (21.95 cm). Only one genotype DHBR-116 recorded significantly higher secondary root length (25.50 cm) than superior check, DS-28 (19.96 cm)