Crop Improvement Division, ICAR-National Rice Research Institute, Cuttack, India.
ICAR-National Research Center for Plant Biotechnology, Pusa, New Delhi, India.
Mol Genet Genomics. 2019 Aug;294(4):963-983. doi: 10.1007/s00438-019-01556-w. Epub 2019 Apr 8.
Rice is the staple food for majority of the global population. But, rice grain has low protein content (PC). Mapping of QTLs controlling grain PC is essential for enhancement of the trait through breeding programs. A shortlisted panel population for grain protein content was studied for genetic diversity, population structure and association mapping for grain PC. Phenotyping results showed a wide variation for grain PC. The panel population showed a moderate level of genetic diversity estimated through 98 molecular markers. AMOVA and structure analysis indicated linkage disequilibrium for grain PC and deviation of Hardy-Weinberg's expectation. The analysis showed 15% of the variation among populations and 73% among individuals in the panel population. STRUCTURE analysis categorized the panel population into three subpopulations. The analysis also revealed a common primary ancestor for each subpopulation with few admix individuals. Marker-trait association using 98 molecular markers detected 7 strongly associated QTLs for grain PC by both MLM and GLM analysis. Three novel QTLs qPC3.1, qPC5.1 and qPC9.1 were detected for controlling the grain PC. Four reported QTLs viz., qPC3, QPC8, qPC6.1 and qPC12.1 were validated for use in breeding programs. Reported QTLs, qPC6, qPC6.1 and qPC6.2 may be same QTL controlling PC in rice. A very close marker RM407 near to protein controlling QTL, qProt8 and qPC8, was detected. The study provided clue for simultaneous improvement of PC with high grain yield in rice. The strongly associated markers with grain PC, namely qPC3, qPC3.1, qPC5.1, qPC6.1, qPC8, qPC9.1 and qPC12.1, will be useful for their pyramiding for developing protein rich high yielding rice.
大米是全球大多数人口的主食。但是，稻谷的蛋白质含量（PC）较低。通过育种计划，对控制粒 PC 的 QTL 进行基因定位对于提高该性状至关重要。对一个经筛选的粒蛋白含量的作图群体进行了遗传多样性、群体结构和关联作图分析，以研究粒 PC。表型分析结果表明粒 PC 存在广泛的变异。该作图群体通过 98 个分子标记显示出中等水平的遗传多样性。AMOVA 和结构分析表明粒 PC 存在连锁不平衡和偏离 Hardy-Weinberg 预期。分析表明，群体间变异的 15%和作图群体中个体间变异的 73%。STRUCTURE 分析将作图群体分为三个亚群。分析还揭示了每个亚群的共同原始祖先和少数混合个体。使用 98 个分子标记进行标记-性状关联分析，通过 MLM 和 GLM 分析检测到控制粒 PC 的 7 个强关联 QTL。检测到控制粒 PC 的三个新 QTL qPC3.1、qPC5.1 和 qPC9.1。验证了四个报道的 QTL，即 qPC3、QPC8、qPC6.1 和 qPC12.1，可用于育种计划。报道的 QTL qPC6、qPC6.1 和 qPC6.2 可能是控制水稻 PC 的相同 QTL。在蛋白质控制 QTL qProt8 和 qPC8 附近检测到非常接近的标记 RM407。该研究为在水稻中同时提高 PC 和高谷物产量提供了线索。与粒 PC 强关联的标记，即 qPC3、qPC3.1、qPC5.1、qPC6.1、qPC8、qPC9.1 和 qPC12.1，将有助于它们的聚合，从而开发出富含蛋白质的高产水稻。
