Yang Weifeng, Liang Jiayan, Hao Qingwen, Luan Xin, Tan Quanya, Lin Shiwan, Zhu Haitao, Liu Guifu, Liu Zupei, Bu Suhong, Wang Shaokui, Zhang Guiquan
Guangdong Provincial Key Laboratory of Plant Molecular Breeding, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China.
Rice (N Y). 2021 Apr 1;14(1):33. doi: 10.1186/s12284-021-00476-x.
Grain chalkiness is one of important factors affected rice grain quality. It is known that chalkiness is affected by the high temperature during the seed filling period. Although a larger of QTLs for chalkiness were reported across all 12 chromosomes, only a few of the QTLs were fine mapped or cloned up to now. Here, we fine map two QTLs for chalkiness in two single-segment substitution lines (SSSLs), 11-09 with substitution segment from O. sativa and HP67-11 with substitution segment from O. glaberrima.
The grain chalkiness of SSSLs 11-09 and HP67-11 was significantly lower than that in the recipient Huajingxian 74 (HJX74) in consecutive 8 cropping seasons. The regression correlation analysis showed that percentage of chalky grain (PCG) and percentage of chalky area (PCA) were significantly and positively correlated with percentage of grain chalkiness (PGC). Two QTLs for grain chalkiness were located on two chromosomes by substitution mapping. qPGC9 was mapped on chromosome 9 with an estimated interval of 345.6 kb. qPGC11 was located on chromosome 11 and delimited to a 432.1 kb interval in the O. sativa genome and a 332.9 kb interval in the O. glaberrima genome. qPGC11 is a QTL for grain chalkiness from O. glaberrima and was mapped in a new region of chromosome 11. The effect of two QTLs was incomplete dominance. The additive effects of two QTLs on chalkiness in second cropping season (SCS) were significantly greater than that in first cropping season (FCS).
qPGC11 is a new QTL for grain chalkiness. The two QTLs were fine mapped. The donor alleles of qPGC9 and qPGC11 were sensitive to the high temperature of FCS.
稻米垩白是影响稻米品质的重要因素之一。已知垩白受灌浆期高温影响。尽管在所有12条染色体上都报道了大量与垩白相关的数量性状基因座（QTL），但截至目前，只有少数QTL被精细定位或克隆。在此，我们在两个单片段代换系（SSSL）中精细定位了两个与垩白相关的QTL，11 - 09代换片段来自栽培稻，HP67 - 11代换片段来自光稃稻。
在连续8个种植季中，SSSLs 11 - 09和HP67 - 11的稻米垩白显著低于受体华粳籼74（HJX74）。回归相关分析表明，垩白粒率（PCG）和垩白面积率（PCA）与籽粒垩白度（PGC）显著正相关。通过代换作图在两条染色体上定位了两个籽粒垩白QTL。qPGC9定位在第9染色体上，估计区间为345.6 kb。qPGC11位于第11染色体上，在栽培稻基因组中限定于432.1 kb区间，在光稃稻基因组中限定于332.9 kb区间。qPGC11是来自光稃稻的籽粒垩白QTL，定位在第11染色体的一个新区域。两个QTL的效应为不完全显性。两个QTL在第二季种植（SCS）对垩白的加性效应显著大于第一季种植（FCS）。
qPGC11是一个新的籽粒垩白QTL。两个QTL被精细定位。qPGC9和qPGC11的供体等位基因对第一季种植的高温敏感。
