2个小麦AL型细胞质雄性不育系的异交特性分析

提高不育系的异交结实率是杂交小麦制种产量取得突破的重要途径。为明确小麦AL型雄性不育系的异交结实特性，连续3年测定了2个小麦AL型不育系36A和3235A的柱头活力、柱头外露率、颖间距和自然异交结实率。结果表明，36A和3235A的平均自然异交结实率分别为113.02%和44.65%，柱头活力分别为104.96%和76.7%，差异均达到显著水平；二者的柱头外露率和颖间距无显著差异。相关分析表明，授粉天数与柱头活力呈显著负相关，柱头活力随授粉天数的延长而降低；柱头活力与柱头外露率和颖间距、柱头外露率与颖间距间均呈显著正相关。随授粉进程推移，柱头活力、柱头外露率和颖间距均呈先增后减趋势，36A的3个指标均高于3235A，综合表现为异交结实率高。花后第4～11天套袋饱和授粉异交结实率最高，授粉后第6～12天，柱头外露率和颖间距均达到最大。因此，小麦AL型不育系的恢复系扬花始期比不育系推迟2～3 d，小花陆续开放、柱头活力也较强，并持续开颖，可保持较高结实率，为最佳授粉时间。

Outcrossing Characteristics of the Two Wheat AL-Type Cytoplasmic Male Sterile Lines

Increasing the outcrossing rate of sterile line in hybrid wheat is an important way to increase hybrid seed yield. In order to determine the seed setting of outcross characteristics of wheat AL-type male sterile line, two AL-type sterile lines were selected in this study, and the stigma vigour, stigma exsertion rate, glume spacing and natural outcrossing rate of the sterile lines were measured for three consecutive years. The results showed that the average natural outcrossing rate of 36A and 3235A were 113.02% and 44.65%, and the stigma vigour was 104.96% and 76.7%, respectively. No significant differences was found in stigma exsertion rate and angle of glume opening. Correlation analysis showed that there was a significantly negative correlation between the stigma vigour and the number of days after anthesis, which indicated that the stigma vigour decreased with the number of days after anthesis. The stigma vigour was significantly positively correlated with stigma exsertion rate and glume spacing. In the process of pollination, stigma vigor, stigma exsertion rate and glumes spacing all increased first and then decreased. The three outcrossing characters of 36A was higher than those of 3235A, and the outcrossing seed rate of 36A was better. By regression analysis, the bagging saturation and outcrossing rate of pollination was the highest from the 4th to 11th day after anthesis, and the stigma exsertion rate and glume spacing were the highest from the 6th to 12th day after anthesis. Therefore, the outcrossing rate can be maintained from the restorer line delayed the flowering period by 2 to 3 days of AL type male sterile line of wheat,which was the best pollination period.