BNS小麦的雄性不育性及其温光特性

 【目的】研究BNS育性及其温光特性,探寻育性转换规律,确定其应用价值。【方法】以BNS和百农矮抗58为试材,进行秋季分期播种和春季播种试验,测定不同播期的育性及其日均温度、日照长度的动态变化和温光效应。【结果】(1)BNS小麦雄性不育系的麦穗蓬松,颖壳开张,有透明感;花药干瘪瘦小、不外挂,无或有极少量无活力的花粉,呈圆败型败育;自交不结实,且不育性能稳定遗传;国内、国际法人工饱和授粉结实率79.64%～87.22%、89.89%～102.10%,雌蕊活性正常。(2)BNS温度敏感期为小花原基分化期至雌雄蕊分化期,温度7.4～11.4℃,不育度97.57%～100%(10月17日前播种),高于11.4℃时,育性发生转换,自交结实率随播期的延迟呈现由低(7.71%、9.41%)渐高(70.15%、102.50%)的趋势,不育度则反之;雄性不育性与温度相关密切r=-0.578～-0.866>r0.05/0.01=0.532/0.661;春播BNS的同期温度为15.9℃,自交结实率与对照品种相近,表现正常可育。(3)BNS育性转换时期的自交结实大都集中于麦穗基部、中部,上部几乎不实,与主茎穗比,下落穗易结实,不育性较低。(4)BNS育性变化与光照长度因播期和抽穗前时段的不同表现有所差异,但未有明显的规律。【结论】BNS是光照辅助的温敏型小麦雄性不育系,具有低温不育高温可育的特性。在当地能秋播制种和春播繁殖种子。

Male Sterility and Thermo-Photosensitivity Characteristics of BNS in Wheat

【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.