Abstract:

【Objective】 In order to evaluate the heterosis utilization of BNS in wheat, the fertile performance, thermo-photosensitive characteristics and the fertile conversion were studied with BNS and Bainongaikang 58 in present work.【Method】 The method of time sowing was conducted in autumn as well as the sowing in spring. The temperature and light length were also recorded to study the fertility, dynamics of average daily temperature and light length, and the thermo-photosensitive effect.【Result】 The result showed that the spikes of BNS were light, shag and expanding. The anthers were slim and thin. A little present pollen was lack of activity, and the sterile type of spherical abortion was identified by iodine-treatment. The male-sterile lines exhibited high and stable sterility. The national and international seed setting rate of artificial saturation pollination ranged from 79.64% to 87.22% and 89.89% to 102.10%, respectively, indicating that the pistil was normal. The thermo-sensitive stage of BNS with high sterility (97.57%-100%) was from the differentiating period of floret primordium to pistil and stamen primordium, when the sowing date was earlier than October 17, and the temperature ranged from 7.4℃ to 11.4℃ in this period. The transformation of fertility was detected, with a range of self-seeds rate from 7.71% to 70.15% (National) and 9.41% to 102.50% (International), when the temperature was higher than 11.4℃ in the following sowing dates. Correlation analysis was performed to detect the relationship between sterile degree and temperature. The correlation coefficients (r) ranged from -0.578 to -0.866 (r0.05/0.01=0.532/0.661), which indicated that correlation was significant or extremely significant between sterile degree and temperature. Similar to referenced material Bainongaikang 58, BNS sowed in spring was fertile with the temperature up to 15.9℃ during the differentiating stage of floret primordium to pistil and stamen primordium. During the transforming stage of fertility, the sites of seed setting were mainly on basal and middle spikelets but top ones. Compared with caulis spikes, the male sterility of whereabout spikes was lower. There were differences between transformation of fertility and light length with different sowing dates and stages before heading, but no obvious regularity was found. 【Conclusion】 Above all, BNS was a kind of male-sterile line with thermo-sensitive characteristics, and its sterility was induced by low temperature with the assistant of light. With this promising male-sterile line, the production of hybrid seed and seed of male-sterile line in local areas could be conducted easily with autumn sowing and spring sowing.

Key words: common wheat (Triticum aestivum L.)')">common wheat (Triticum aestivum L.), thermo-sensitive male sterility, transformation of fertility, critical temperature