Genetic mechanisms underlying grain yield

自‘杂种优势’这个术语被创造出来用来描述F1优于亲本的现象以来，已经过去了一百年。经过60多年的自交/杂交育种，杂交种产量提高了7倍，但杂交种和自交系之间的产量差距仍然存在2-3倍，杂种优势的大小保持不变。杂种优势从根本上改变了玉米植株生物学的许多方面，包括在转录水平上，因为表达阵列结果表明，由于顺式和反式效应，杂交种与其自交系亲本相比，基因表达存在差异。在这项提议中，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)，这些基因和过程与决定玉米潜在籽粒数量有关。玉米籽粒数与籽粒产量成正比，这一发育过程被称为“库建立”。此外，我们还将研究涉及或影响库形成的几个范例：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.