Male sterility- New Frontiers in Cotton Breeding
Feb 11, 2019
Conventional hybrid cottonseed production is expensive and this has paved the way for intensification of research into male sterility systems in cotton. Histological, morphological differences, yield and fiber properties and changed restorer background were studied to establish facts on male sterility systems. Post meiotic obstruction in pollen development in GMS and pre-meiotic abnormalities in CGMS caused sterility in cotton. Morphologically fertile and sterile counterparts looked alike except for flower traits where significant reductions in ovary size, staminal column, style and anther filament length and anther number in CGMS. This was not apparent with GMS. Despite reports of reduction in yield with CGMS based hybrids compared to conventional hybrids of the same parents, some entirely new combinations of CGMS hybrids proved economically worthwhile. A comparison between two restorer lines, one based on G. hirsutum and the other on G. harknessii backgrounds, the latter proved superior for stable restoration. Among 64 lines converted, eight had a GOT above 40%, 33 had a seed index of 10 g or more and 11 had a halo length above 30 mm. A halo length of 28 mm, seed index up to 12 g and GOT up to 40% was observed in R lines. Hybrids of selected 12 lines and eight R lines exhibited heterosis for yield and boll features compared to the conventional checks. This emphasizes better performance of diversified A and R lines for hybrid production. The possibility of good CGMS lines in G aridum background is predicted.