中文摘要：

Kr1基因是小麦远缘杂交不亲和主效基因,为了解其表达及调控机制,本研究系统比较了小麦自花授粉和小麦×玉米远缘杂交两个过程中Kr1基因的表达差异,同时分析了这两个过程中Kr1基因部分序列的DNA甲基化状态。结果表明,Kr1基因在小麦自花授粉过程中始终处于低量表达或不表达状态,而在小麦×玉米远缘杂交过程中的表达呈动态变化,具体表现为授粉前低量表达,授粉后迅速大量表达,24h后又恢复为低量表达,高峰表达时期在外源花粉授入后0.5~2h左右。DNA甲基化分析显示,小麦自花授粉前后Kr1基因一直处于较高水平的甲基化状态,分别为58%和62%;而在授以玉米花粉后,Kr1基因迅速去甲基化,在0.5h内降到12%,在其后的1、2、24h内一直维持在10%~12%的低甲基化水平,表明DNA甲基化修饰参与了Kr1基因在小麦×玉米远缘杂交中的表达调控。

英文摘要：

Krl gene is the major gene regulating incompatibility in wheat distant hybridization. To un- derstand its expression and regulation mechanism, the difference of Krl expression in the two systems of wheat self pollination and wheat X maize distant hybridization were compared systematically in this work, and the variations of DNA methylation of Krl gene during the self-pollination and distant hy- bridization processes were analyzed. The results showed that the expression level of Krl gene was al- ways low or even no expression in the process of wheat self-pollination. However, its expression showed a dynamic change in wheat ）〈 maize distant hybridization, with low expression before pollina tion, a rapid great increase of expression after pollination, and low expression after 24 h. The peak expression period was present at about 0.5--2 h after pollinated with the foreign pollen. DNA methy- lation analysis shows thatKrl gene stays a high level status before and after the self-pollination, with the proportion of 58% and 62%, respectively. However, after pollinated with maize pollen, Krl gene is rapidly de methylated, dropping to a level of 12% in 0.5 h, and maintains at the low level of 10% to 12%methylation in the subsequent 1, 2, and 24 h. These findings indicate that DNA methylation modification is participated in the expression and regulation of KrI gene in wheat X maize distant hybridization.