杂种优势在提高粮食作物特别是玉米的产量方面具有重要的作用。然而,杂种优势的原理却仍然是一个世界性的难题。用12个玉米自交系及其按不完全双列杂交组配的33个杂交种为材料,分4个不同发育时期取杂交种及其亲本的雌穗组织,利用差异显示技术,分析杂种与亲本的基因差异表达类型及其与7个主要农艺性状的杂种表现和杂种优势的相关关系。发现1):在5种表达类型中单态表达(基因在杂交种和双亲中同时表达的类型)的数量最大,这说明杂种优势的形成不仅与基因的表达与否相关,还与大量基因的上调或下调表达相关;2):在玉米雌幼穗的发育初期杂交种与双亲的基因表达差异最大,这可能与雌穗发育初期器官的形成和发育相关,因此这一时期差异表达(在质的方面)的基因对产量性状和杂种优势的形成具有密切关系;3):综合各种基因表达类型与产量性状和杂种优势的关系,发现某些基因在杂种中的沉默表达可以促进籽粒的发育和抑制幼穗中小花的发育。 Heterosis has an important role in increasing the production of food crops, especially corn. However, the principle of heterosis is still a worldwide problem. Twelve maize inbred lines and 33 hybrids based on incomplete diallel cross were used as materials to divide the ear tissues of four hybrids and their parents at different developmental stages. Differential display The parental genes were differentially expressed and their relationships with seven major agronomic traits and heterosis. The results showed that: 1): The number of single-state expression (the type of genes expressed simultaneously in hybrids and parents) among the five expression types is the largest, indicating that the formation of heterosis is not only related to the gene expression but also to the gene Upregulation or down-regulation of expression; 2) Gene expression difference between hybrids and parents was the highest at the early stage of young corn ear development, which may be related to the formation and development of organs at early stage of ear development. Therefore, ) Were closely related to the formation of yield traits and heterosis. 3) Based on the relationship between the expression types of various genes and yield traits and heterosis, it was found that the silencing of certain genes in hybrids could promote the development of grain And inhibit the development of small flowers in inflorescences.