Development of Genetic Broadening System in Cotton through Artificial Crosses between 2x and 4x Species

Abstract

In order to establish a reliable genetic broadening system in cotton, artificial crossing have been made between wild type cotton species (2x) and tetraploid (4x) commercial cotton varieties. 100 ppm giberlic acetic acid to prevent pollinated flower abscission for seven days after pollination. Highly significant differences have been observed between control and hormone growth regulator for hybrid boll setting at α=0.05 level using Chi-square test. In spite of a few boll developments, in control treatment, no seed was observed after after 45 DAP (Day after pollination).Analysis of collected data showed that there was a significant difference between crosses for boll development at α=0.05 level through Chi-square test. There was significant differences between diploid (25%) and tatraploid (43.5%) female parents for boll setting when used as female parent in crosses at α=0.05 level. Maximum boll development (64%) has been observed in Sephid as atetraploid with Hashem – Abad (2x) when treated with 100 ppm GA3 after 45 DAP. The seeds were not as well developed as those from the self pollinated female parents. The sterile triploid hybrid plant showed more vigorous than either parent.