Characterization of cytoplasmic male sterile lines in wheat (Triticum aestivum L.).

摘要

Various floral and agronomic traits in 39 cytoplasmic male sterile wheat lines (CMS or A lines) representing 7 different cytoplasmic sources and their corresponding maintainers (B lines) were studied in New Delhi, India, during the 1999/2000 rabi season, with respect to different sowing dates (26 November, 11 December and 28 December). Significant variation between the CMS lines and B lines was observed with respect to different floral (anther size, filament length, ovary size and length of style) and agronomic traits (plant height, number of tillers, spike length, number of spikelets per main spike, days to 50% flowering and synchrony of tillers). The mean values for different floral traits in the CMS lines was lower than or equal to that of their fertile counterparts. Opened glume angle had the highest variation (the lowest was 5-7 degrees and the highest 17-20 degrees) within the CMS lines carrying the same cytoplasm and among the CMS lines carrying diverse cytoplasm. Stigma receptivity had the least variation, which ranged from 4 to 5 days among various CMS lines. All the CMS lines exhibited complete pollen sterility at the 3 sowing dates. The number of tillers per plant was reduced in most of the CMS lines and the differences were significant only in a few cases. Reduction in plant height, spike length and spikelet number per spike was observed, both in positive and negative directions. Majority of CMS lines flowered significantly later than their respective B lines. A more or less stable performance was observed in the 39 CMS lines studied based on floral and agronomic traits. Preliminary studies on natural crossing in CMS lines indicated a ratio of 1B:3A as the optimal row ratio for enhanced seed yield.