中文摘要：

杂种优势在内部节点延伸和植物高度通常在混合植物，而是的分子的基础被观察增加内部在混血儿的节点延伸是未知的。在这研究，在植物高度的中间的父母杂种优势在包含 16 个混血儿和 8 个父母的一个小麦 diallel 十字被决定，并且即时 PCR 被用来在在混血儿和父母之间的基因表示分析改变。植物高度的重要杂种优势并且第一内部在长度的节点为所有 16 个混血儿被观察，但是杂种优势的大小为不同生气联合是可变的。分析表明杂种优势第一内部节点显著地被相关到植物高度的(r = 0.56， P 【 0.05 ) ，建议增加的延伸第一内部节点是到在植物高度的杂种优势的主要贡献者。实时 PCR 分析在基因表示的杂种优势展出了那重要差别在所有生气联合之中被观察。而且，杂种优势第一内部在长度的节点与 KS ， GA3ox2-1 ， GA20ox2 ， GA20ox1D ， GA-MYB 和 GID1-1 的表示杂种优势显著地并且断然被相关，但是显著地并且否定地与 GAI 和 GA2ox-1 的表示杂种优势，它在小麦植物高度与我们气体和杂种优势的最近建议的模型一致，建议 GA 生合成和反应小径的改变可能为在植物高度的观察杂种优势负责。

英文摘要：

Heterosis in internode elongation and plant height is commonly observed in hybrid plants, but the molecular basis for the increased internode elongation in hybrids is unknown. In this study, midparent heterosis in plant height was determined in a wheat diallel cross involving 16 hybrids and 8 parents, and real-time PCR was used to analyze alterations in gene expression between hybrids and parents. Significant heterosis of plant height and the first internode in length were observed for all 16 hybrids, but the magnitude of heterosis was variable for different cross combinations. Analysis revealed that the heterosis of the first internode was significantly correlated to that of plant height （r = 0.56, P 〈 0.05）, suggesting that the increased elongation of the first internode is the major contributor to the heterosis in plant height. Real-time PCR analysis exhibited that significant difference in heterosis of gene ex- pression was observed among all cross combinations. Moreover, heterosis of the first internode in length was correlated significantly and positively with expression heterosis of KS, GA3ox2-1, GA20ox2, GA20ox1D, GA-MYB and GID1-1, but significantly and negatively with expression heterosis of GAI and GA2ox-1, which is consistent with our recently proposed model of GAs and heterosis in wheat plant height, suggesting the alteration of GA biosynthesis and response pathways might be responsible for the observed heterosis in plant height.