Upadhyaya Hari D, Wang Yi-Hong, Sastry Dintyala V S S R, Dwivedi Sangam L, Prasad P V Vara, Burrell A Millie, Klein Robert R, Morris Geoffrey P, Klein Patricia E
a International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru 502 324, Andhra Pradesh, India.
b Department of Agronomy, Kansas State University, Manhattan, KS 66506, USA.
Genome. 2016 Feb;59(2):137-45. doi: 10.1139/gen-2015-0122. Epub 2015 Nov 24.
Sorghum is one of the world's most important food, feed, and fiber crops as well as a potential feedstock for lignocellulosic bioenergy. Early-season planting extends sorghum's growing season and increases yield in temperate regions. However, sorghum's sensitivity to low soil temperatures adversely impacts seed germination. In this study, we evaluated the 242 accessions of the ICRISAT sorghum mini core collection for seed germination and seedling vigor at 12 °C as a measure of cold tolerance. Genome-wide association analysis was performed with approximately 162,177 single nucleotide polymorphism markers. Only one marker locus (Locus 7-2) was significantly associated with low-temperature germination and none with vigor. The linkage of Locus 7-2 to low-temperature germination was supported by four lines of evidence: strong association in three independent experiments, co-localization with previously mapped cold tolerance quantitative trait loci (QTL) in sorghum, a candidate gene that increases cold tolerance and germination rate when its wheat homolog is overexpressed in tobacco, and its syntenic region in rice co-localized with two cold tolerance QTL in rice. This locus may be useful in developing tools for molecular breeding of sorghums with improved low-temperature germinability.
高粱是世界上最重要的粮食、饲料和纤维作物之一，也是木质纤维素生物能源的潜在原料。早季种植可延长高粱的生长季节并提高温带地区的产量。然而，高粱对土壤低温的敏感性会对种子萌发产生不利影响。在本研究中，我们评估了国际半干旱热带作物研究所（ICRISAT）高粱微型核心种质库的242份材料在12°C下的种子萌发和幼苗活力，以此作为耐寒性的衡量指标。利用约162,177个单核苷酸多态性标记进行了全基因组关联分析。只有一个标记位点（位点7-2）与低温萌发显著相关，与活力无关。位点7-2与低温萌发的连锁关系得到了四条证据的支持：在三个独立实验中表现出强关联、与高粱中先前定位的耐寒数量性状位点（QTL）共定位、一个候选基因在烟草中过表达其小麦同源基因时可提高耐寒性和发芽率，以及其在水稻中的同线区域与水稻中的两个耐寒QTL共定位。该位点可能有助于开发具有提高低温发芽能力的高粱分子育种工具。
