Genetic mechanisms underlying grain yield

自从“杂种优势”一词被用来描述F1基因型优于亲本基因型的现象以来，已经过去了100年。经过60多年的自交系/杂交系育种，杂交系的产量提高了7倍，但杂交系与自交系的产量差异仍然存在2 ~ 3倍，杂种优势的大小没有变化。杂种优势从根本上改变了玉米植株生物学的许多方面，包括转录水平，因为表达阵列结果表明，与近交亲本相比，杂交种中由于顺式和反式效应而导致的基因表达差异。在本提案中，我的研究小组将利用杂种优势现象来确定一组候选基因和过程（即调控网络），这些基因和过程参与决定玉米的潜在粒数。玉米的粒数与产量成正比，这一发育过程被称为“库建立”。此外，我们将研究涉及或影响库建立的几个范例：产量稳定性，G×E，叶数和开花时间。

One hundred years have elapsed since the term 'heterosis' was coined to describe the phenomenon of the superiority of the F1 over the parental genotypes. After more than 60 years of inbred/hybrid breeding resulting in a 7-fold increase in hybrid grain yield, a 2- to 3-fold difference in grain yield between hybrids and inbreds still exists and the magnitude of heterosis remains unchanged. Heterosis fundamentally changes many aspects of the biology of the maize plant, including at the transcriptional level as expression array results have demonstrated differential expression of genes due to both cis- and trans- effects in hybrids as compared to their inbred parents. In this proposal my research group will be exploiting the phenomena of heterosis to identify a set of candidate genes and processes (i.e., regulatory networks) involved in determining potential kernel number in maize. Kernel number is maize is directly proportional to grain yield and this developmental process is referred to as 'sink establishment'. In addition we will be examining several paradigms that involve or influence sink establish: yield stability, G×E, leaf number, and flowering time.