Samonte Stanley Omar Pb, Ponce Kimberly S, Sanchez Darlene L
Texas A&M AgriLife Research Center, Beaumont, TX, 77713, USA.
Rice (N Y). 2024 Nov 22;17(1):71. doi: 10.1186/s12284-024-00751-7.
Carbohydrate stress reduces grain size and head rice percentage and increases the chalkiness in rice. This study aims to compare low and high-quality cultivars for their milled rice and chalky grain percentages, as well as grain size, in the top, middle, and bottom panicle portions. Low-chalky and chalky long-grain rice cultivars were grown at Beaumont in 2019 and 2022. Panicles were harvested, partitioned into top, middle, and bottom portions, and phenotyped for grain size, head rice percentage, and chalkiness. Grain area reduction percentage from top to middle panicle portions is higher in the low-chalky cultivars, Presidio and Kaybonnet. This could relieve the carbohydrate stress that leads to chalkiness. The rice cultivars were also genotyped for Chalk5 and OsPPDK. The low-chalky cultivars had the same allele as the low-chalk Lemont for Chalk5. Presidio had a different allele for OsPPDK compared with the cultivars tested. Consistent with the genotyping result for Chalk5, Presidio and Kaybonnet had lower chalkiness than LaGrue and Leah. There was a positive correlation between the number of primary panicle branches and head rice percentage. The improvement in breeding efficiency for high grain quality requires phenotypic screening for a high number of primary panicle branches and for low chalky and partially chalky grain percentages.
碳水化合物胁迫会减小水稻粒形并降低整精米率，同时增加垩白度。本研究旨在比较优质和低质品种在穗部上、中、下部位的糙米率、垩白粒率以及粒形。2019年和2022年在博蒙特种植了低垩白和高垩白的长粒水稻品种。收获稻穗，将其分为上、中、下部分，并对粒形、整精米率和垩白度进行表型分析。低垩白品种Presidio和Kaybonnet从穗上部到中部的粒面积减少百分比更高。这可能缓解了导致垩白的碳水化合物胁迫。还对这些水稻品种进行了Chalk5和OsPPDK基因分型。低垩白品种在Chalk5基因上与低垩白品种Lemont具有相同的等位基因。与所测试的其他品种相比，Presidio在OsPPDK基因上具有不同的等位基因。与Chalk5基因分型结果一致，Presidio和Kaybonnet的垩白度低于LaGrue和Leah。一次枝梗数与整精米率之间存在正相关。提高高粒质育种效率需要对大量一次枝梗以及低垩白和部分垩白粒率进行表型筛选。
