Various floral and agronomic traits in 39 cytoplasmic male sterile wheat lines (CMS or A lines) representing seven different cytoplasmic sources and their corresponding maintainers (8 lines) were studied with respect to different dates of sowing. Significant variation between the CMS lines and 8 lines was observed with respect to fioral traits viz., anther size, filament length, ovary size and length of style and agronomic traits namely 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 lesser than or equal to that of their fertile counterparts. Opened glume angle had maximum variation, the minimum being 5–7 degrees and the maximum of 17–20 degrees within the CMS lines carrying 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 three dates of sowing. The number of tillers per plant was reduced in most of the CMS lines and the differences were significant only in few cases. Reduction in plant height, spike length and spikelet number per spike was observed, both in positive and negative directions. A similar trend was observed with respect to. In this way the interaction of cytoplasms with different nuclear backgrounds can be in positive as well as in negative direction. Majority of CMS lines flowered significantly later than their respective 8 lines. The results of present study indicate more or less stable performance of 39 CMS lines studied with respect to floral and agronomic traits. The preliminary study on natural crossing in CMS lines indicated that the ratio 18:3A as the optimal row ratio for enhanced seed yield.
Wheal, cytoplasmic male sterility, Triticum timopheevi, T. araraticum, Aegilops speltoides, floral and agronomic traits, pollen sterility
