Institute of Crop Science, NARO, Tsukuba, Japan.
Theor Appl Genet. 2016 Dec;129(12):2241-2252. doi: 10.1007/s00122-016-2773-4. Epub 2016 Sep 30.
Integration of previous Mendelian genetic analyses and recent molecular genomics approaches, such as linkage mapping and QTL cloning, dramatically strengthened our current understanding of genetic control of rice flowering time. Flowering time is one of the most important agronomic traits for seed production in rice (Oryza sativa L.). It is controlled mainly by genes associated with photoperiod sensitivity, particularly in short-day plants such as rice. Since the early twentieth century, rice breeders and researchers have been interested in elucidating the genetic basis of flowering time because its modification is important for regional adaptation and yield optimization. Although flowering time is a complex trait controlled by many quantitative trait loci (QTLs), classical genetic studies have shown that many associated genes are inherited in accordance with Mendelian laws. Decoding the rice genome sequence opened a new era in understanding the genetic control of flowering time on the basis of genome-wide mapping and gene cloning. Heading date 1 (Hd1) was the first flowering time QTL to be isolated using natural variation in rice. Recent accumulation of information on rice genome has facilitated the cloning of other QTLs, including those with minor effects on flowering time. This information has allowed us to rediscover some of the flowering genes that were identified by classical Mendelian genetics. The genes characterized so far, including Hd1, have been assigned to specific photoperiod pathways. In this review, we provide an overview of the studies that led to an in-depth understanding of the genetic control of flowering time in rice, and of the current state of improving and fine-tuning this trait for rice breeding.
先前的孟德尔遗传分析与最近的分子基因组学方法（如连锁图谱绘制和 QTL 克隆）的结合，极大地增强了我们目前对水稻开花时间遗传控制的理解。开花时间是水稻（Oryza sativa L.）种子生产中最重要的农艺性状之一。它主要由与光周期敏感性相关的基因控制，特别是在短日照植物如水稻中。自 20 世纪初以来，水稻育种家和研究人员一直致力于阐明开花时间的遗传基础，因为其修饰对于区域适应和产量优化很重要。尽管开花时间是一个由多个数量性状位点（QTL）控制的复杂性状，但经典遗传研究表明，许多相关基因按照孟德尔定律遗传。解码水稻基因组序列为在全基因组图谱绘制和基因克隆的基础上理解开花时间的遗传控制开辟了一个新时代。Heading date 1 (Hd1) 是第一个使用水稻自然变异分离的开花时间 QTL。最近，水稻基因组信息的积累促进了其他 QTL 的克隆，包括对开花时间影响较小的 QTL。这些信息使我们能够重新发现一些通过经典孟德尔遗传学鉴定的开花基因。迄今为止，已鉴定出的基因包括 Hd1，它们被分配到特定的光周期途径中。在这篇综述中，我们概述了导致对水稻开花时间遗传控制的深入理解的研究，并概述了目前对该性状进行改良和微调以用于水稻育种的现状。
