Ohlson Erik W, Thio Gilles I, Sawadogo Mahamadou, Sérémé Paco, Timko Michael P
1Department of Biology, University of Virginia, Charlottesville, VA 22904 USA.
2Laboratory of Genetic and Plant Biotechnology, Institut de l'Environnement et de Recherches Agricoles (INERA), Ouagadougou, 01 BP 476 Burkina Faso.
Mol Breed. 2018;38(9):110. doi: 10.1007/s11032-018-0867-1. Epub 2018 Aug 16.
Cowpea is one of the most important crops in West Africa and is essential for the region's food and nutrition security and economic development. Consequently, improving its agronomic performance and yield is a desirable goal. Brown blotch disease, caused by the fungal pathogen , is an important constraint of cowpea productivity, and at present, only limited genetic resources are available for breeding improved brown blotch-resistant varieties. The current study has characterized the genetic basis for brown blotch resistance conferred by the cowpea cultivar KN1 and identified a major dominant quantitative trait locus (QTL) for resistance on chromosome Vu02. A segregating F population ( = 200), derived from a cross between KN1 and brown blotch-susceptible Tiligre (KVx775-33-2G), was developed and scored for disease severity following controlled inoculation. A subset of the population ( = 94) was genotyped with 99 newly developed allele-specific polymerase chain reaction (AS-PCR) markers, and multiple interval mapping was performed. One major and three minor QTL were identified. This is the first reported mapping of QTL conferring resistance to in cowpea, and it is expected that the markers identified here will be a valuable resource for developing elite cowpea cultivars with resistance to brown blotch.
豇豆是西非最重要的作物之一，对该地区的粮食和营养安全以及经济发展至关重要。因此，提高其农艺性能和产量是一个理想的目标。由真菌病原体引起的褐色斑点病是豇豆生产力的一个重要限制因素，目前，用于培育改良抗褐色斑点品种的遗传资源有限。当前的研究已经对豇豆品种KN1赋予的抗褐色斑点的遗传基础进行了表征，并在Vu02染色体上鉴定出一个主要的显性数量性状位点（QTL）用于抗性。构建了一个分离的F群体（n = 200），该群体来自KN1和感褐色斑点的Tiligre（KVx775-33-2G）之间的杂交，并在控制接种后对病害严重程度进行评分。使用99个新开发的等位基因特异性聚合酶链反应（AS-PCR）标记对该群体的一个子集（n = 94）进行基因分型，并进行多重区间作图。鉴定出一个主要QTL和三个次要QTL。这是首次报道在豇豆中定位赋予对褐色斑点抗性的QTL，预计这里鉴定出的标记将成为培育抗褐色斑点优良豇豆品种的宝贵资源。
