Liu G, Jia Y, McClung A, Oard J H, Lee F N, Correll J C
Rice Research and Extension Center, University of Arkansas, Stuttgart 72160.
United States Department of Agriculture-Agricultural Research Service, Dale Bumpers National Rice Research Center, Stuttgart, AR 72160.
Plant Dis. 2013 Jan;97(1):113-117. doi: 10.1094/PDIS-05-12-0466-RE.
Rice sheath blight disease, caused by Rhizoctonia solani AG1-1A, is one of the most destructive rice diseases worldwide. Utilization of host resistance is the most economical and environmentally sound strategy in managing sheath blight (ShB). Ten ShB quantitative trait loci (QTLs) were previously mapped in a Lemont × Jasmine 85 recombinant inbred line (LJRIL) population using greenhouse inoculation methods at an early vegetative stage. However, confirmation of ShB-resistant QTLs under field conditions is critical for their utilization in marker-assisted selection (MAS) for improving ShB resistance in new cultivars. In the present study, we evaluated ShB resistance using 216 LJRILs under field conditions in Arkansas, Texas, and Louisiana during 2008 and 2009. We confirmed the presence of the major ShB-QTL qShB9-2 based on the field data and also identified one new ShB-QTL between markers RM221 and RM112 on chromosome 2 across all three locations. Based on the field verification of ShB evaluations, the microchamber and mist-chamber assays were simple, effective, and reliable methods to identify major ShB-QTLs like qShB9-2 in the greenhouse at early vegetative stages. The markers RM215 and RM245 were found to be closely linked to qShB9-2 in greenhouse and field assays, indicating that they will be useful for improving ShB resistance in rice breeding programs using MAS.
由立枯丝核菌AG1-1A引起的水稻纹枯病是全球最具破坏性的水稻病害之一。利用寄主抗性是防治纹枯病最经济且环保的策略。先前在一个Lemont×Jasmine 85重组自交系（LJRIL）群体中，于营养生长早期采用温室接种方法定位了10个纹枯病数量性状位点（QTL）。然而，在田间条件下对纹枯病抗性QTL进行验证，对于其在标记辅助选择（MAS）中用于改良新品种的纹枯病抗性至关重要。在本研究中，我们于2008年和2009年在阿肯色州、得克萨斯州和路易斯安那州的田间条件下，利用216个LJRIL评估了纹枯病抗性。基于田间数据，我们确认了主要纹枯病QTL qShB9-2的存在，并且在所有三个地点的第2号染色体上，于标记RM221和RM112之间鉴定出一个新的纹枯病QTL。基于纹枯病评估的田间验证，微室和雾室测定法是在温室营养生长早期鉴定像qShB9-2这样的主要纹枯病QTL的简单、有效且可靠的方法。在温室和田间测定中发现标记RM215和RM245与qShB9-2紧密连锁，这表明它们将有助于在利用MAS的水稻育种计划中提高纹枯病抗性。
