Dear Editor,
Grain size is a major determinant of grain yield and quality in rice (Oryza sativa), and was therefore an important selective target during domestication and breeding (Fitzgerald et al., 2009) (Takano-Kai et al., 2009). In the past few decades, a dozen grain size-related QTLs/genes have been cloned (Huang et al., 2013, Zuo and Li, 2014). Pyramiding grain size QTLs to breed high-yielding and high-quality rice varieties has proved to be a great success. For example, by pyramiding the nonfunctional alleles gs3 and gw8 in line HJX74, Wang et al. (2012) converted a line with short and wide grains into one with slender grains and substantially improved grain quality. By pyramiding the GW7 allele from TFA and gs3, Wang et al. (2015) developed new high-yielding indica hybrid rice varieties with simultaneously improved yield and grain quality. Thus, it is of considerable importance to identify more grain size QTLs to facilitate further improvement in rice yield and quality.
籽粒大小是決定水稻產(chǎn)量和品質(zhì)的主要因素，因此，在馴養(yǎng)和繁殖過程中是一個(gè)重要的選擇性目標(biāo)(Fitzgerald et al., 2009) (Takano-Kai et al., 2009)。在過去的幾十年中，已經(jīng)克隆了十幾個(gè)與籽粒大小相關(guān)的QTLs/基因(Huang et al., 2013, Zuo and Li, 2014)。聚合多個(gè)調(diào)控籽粒大小的QTL來(lái)培育高產(chǎn)優(yōu)質(zhì)水稻品種，已被證明獲得了巨大的成功。例如，通過聚合HJX74中功能缺失的gs3和gw8，Wang(2012)等人將一個(gè)籽粒短而寬的株系改良為細(xì)長(zhǎng)粒，顯著提高了稻谷品質(zhì)。通過聚合gs3和TFA中的GW7，Wang(2015)等人成功培育一個(gè)高產(chǎn)秈稻雜交稻組合，產(chǎn)量和品質(zhì)同時(shí)得到改良。因此，鑒定更多的調(diào)控籽粒大小的QTL，對(duì)于進(jìn)一步提高水稻產(chǎn)量和品質(zhì)具有重要意義。