小麦AL型细胞质雄性不育系异交结实率的研究

Study on the outcross rate of wheat AL type cytoplasmic male sterile lines

不育系异交结实率的高低是由其遗传特性或栽培措施而决定,高异交结实率的不育系选育将是决定小麦杂交种能否推广的前提。该研究选择20个连续回交5代以上的小麦AL型稳定不育系和小麦杂交种新冬43号为研究对象,2014—2016年连续3年对20个稳定的不育系进行不育度、异交结实率和异交实现率的测定;2014年对新冬43号进行了分期制种,开展了异交结实率和制种产量的测定。结果表明:在相同环境条件下,参试不育系之间自然异交结实率差异达到极显著水平,说明遗传因素对不育系异交结实率影响较大;通过对不育系异交结实率和异交结实实现率进行相关分析,表明上述两个指标之间呈极显著正相关。新冬43号大田制种中,在正常播期和晚播制种情况下(父母本行比均为2∶10),不同母本行之间制种产量差异不显著,父本离母本行之间的距离与不育系异交结实率、制种产量均呈负相关,表明栽培措施对不育系异交结实率存在一定的影响;结果还表明:不育系异交结实率与制种产量的正相关系数均达到显著水平。杂交小麦不育系的异交结实率主要受遗传特性影响,异交结实率和异交结实实现率是判定不育系能否应用到生产上的两项重要指标。

The level of outcross rate of male sterile lines is determined by their genetic characteristics or cultivation measures. Selecting fine wheat sterile lines with high outcross rate is basis on hybrid wheat utilization. In this study, we selected 20 wheat stabled sterile lines with more than 5 generations of continuous backcrossing and wheat hybrid variety＂Xindong 43＂ as the research object. From 2014 to 2016, the determination of sterility, outcross rate, and outcross implementation rate of 20 stable CMS lines were conducted. In 2014, ＂Xindong 43＂ was seeded in different stages, and the outcross rate and the yield of seed production were measured. The results showed that under the same environmental conditions, the difference in natural outcross rate among the tested sterile lines reached a very significant level, indicating that genetic factors had a greater influence on the outcross rate of sterile lines.The correlative analysis of the rate of achievement and the rate of out-crossing of the out-crossings showed that there was a very significant positive correlation between the above two indicators. In the field production of ＂Xindong 43＂, under the normal sowing date and late seeding production（parents＇ ratio was 2∶10）, the difference in seed production between different maternal lines was not significant.The distance between the female parent lines and the outcross rate of male sterile lines and the seed production yield were negatively correlated, indicating that the cultivation measures had a certain influence on the outcross seed setting rate of the male sterile lines.The results also showed that the male sterile lines had outcross seed setting rates. The positive correlationcoefficient with the seed production yield reached a significant level. The outcross seed setting rate of hybrid wheat CMS lines was mainly affected by genetic characteristics. The outcross seed setting rate and outcross fruiting rate were two important indicators to determine whether CMS can be applied to production.