School of Genetics, Tamil Nadu Agricultural University, Coimbatore 641003.
* Present address: Department of Agficultural Botany, Agricultural College and Research Institute, Madurai 625104.
A study was undertaken to assess the genetic worth of a fuzzless-lintless spontaneous mutant of variety MCU 5 of G. hirsutum. It was crossed with other genotypes in line X tester design and the combining ability effects were worked out. This mutant had significantly favourable gca effects for seed index, uniformity ratio and maturity of fibres, indicating that the natural mutation has not only affected the major gene for the presence of fuzz or lint, but also influenced other yield and fibre characters through pleiotropism. It will be ideal to combine this mutant separately with MCU 5, DS 28 and MCU 9 to get favourable recombinants for all the fibre traits besides lint yield. The hybrid Express Sindh (W) X fuzzless-lintless mutant appears to be best, combining all the traits studied, thus paving way for exploitation of heterosis in intra-hirsutum crosses.
Breeding value, lintless mutant, cotton, G. hirsutum
