Male Sterility in Cotton and Possibilities for ITS Utilization

Abstract

Five male sterile lines were crossed to the G. hirsutum male parents underthe natural fi eld conditions to produce hybrid plants. At the fl owering time indifferent days and hours, observations were made on pollen sterility. The trialswere carried in 2005 and 2006. Results obtained showed that the availablesterile lines were not completely sterile, there was no pollen in the early hours(from 9 a.m. to 2 p.m.) or in case of presence it was highly sterile. The absenceof pollen in the early hours of day during the fl owering will permit to solve theproblem with the hand emasculation by its reduction in the hybrid cotton seedproduction. At these lines some viable pollen was developed in the later hoursor at the end of fl owering and normal seeds were produced by self-pollination,and it is not necessary to restore fertility or to maintain sterility by the use ofmaintainer lines. The hybrid plants based on male sterility produced under thefree cross pollination were insuffi cient for commercial seed production. Thehighest percent was found to be 67.8 at the line A-21 in 2006. As the very early№ 433 (brown cotton) was used as a pollinator high percent of hybrid plantswas also realized.