Ouédraogo Jeremy T, Tignegre Jean-Baptiste, Timko Michael P, Beizile François J
Institut de l'Environnement et de Recherches Agricoles, Ouagadougou, Burkina Faso.
Genome. 2002 Oct;45(5):787-93. doi: 10.1139/g02-043.
Amplified fragment length polymorphism (AFLP) analysis was used in combination with bulked segregant analysis (BSA) to identify molecular markers linked to two cowpea (Vigna unguiculata (L.) Walp.) genes conferring resistance to Striga gesnerioides race 1. After AFLP analysis of an F2 population derived from a cross between the resistant cultivar Gorom and the susceptible cultivar Tvx 3236, seven AFLP markers were identified that are linked to Rsg3, the gene conferring race I resistance in 'Gorom'. The distances between these markers and Rsg3 ranged from 9.9 to 2.5 cM, with two markers, E-AGA/M-CTA460 and E-AGA/M-CAG300, flanking Rsg3 at 2.5 and 2.6 cM, respectively. Analysis of a second F2 population derived from the cross between 'Tvx 3236' and the resistant cultivar IT81D-994 identified five AFLP markers linked to the race 1 resistance gene 994-Rsg present in 'IT81D-994'. The two markers showing the tightest linkage to the 994-Rsg locus were E-AAG/M-AAC450 and E-AAG/M-AAC150 at 2.1 and 2.0 cM, respectively. Two of the markers linked to 994-Rsg, E-AGA/M-CAG300 and E-AGA/M-CAG450, were also linked to Rsg3. The identification of molecular markers in common between the two sources of race 1 resistance suggests that either Striga resistance genes are clustered in these plants or that these loci are allelic. Mapping of the resistance loci within the cowpea genome revealed that three markers linked to Rsg3 and (or) 994-Rsg are located on linkage group 6.
扩增片段长度多态性（AFLP）分析与集群分离分析法（BSA）相结合，用于鉴定与两个豇豆（Vigna unguiculata (L.) Walp.）抗尖镰孢菌1号生理小种基因连锁的分子标记。在用抗病品种戈罗姆（Gorom）与感病品种Tvx 3236杂交得到的F2群体中进行AFLP分析后，鉴定出7个与Rsg3连锁的AFLP标记，Rsg3是“戈罗姆”中赋予1号生理小种抗性的基因。这些标记与Rsg3之间的距离在9.9至2.5厘摩之间，其中两个标记E-AGA/M-CTA460和E-AGA/M-CAG300分别在2.5和2.6厘摩处位于Rsg3两侧。对由“Tvx 3236”与抗病品种IT81D-994杂交得到的第二个F2群体进行分析，鉴定出5个与“IT81D-994”中存在的1号生理小种抗性基因994-Rsg连锁的AFLP标记。与994-Rsg位点连锁最紧密的两个标记分别是E-AAG/M-AAC450和E-AAG/M-AAC150，距离分别为2.1和2.0厘摩。与994-Rsg连锁的两个标记E-AGA/M-CAG300和E-AGA/M-CAG450也与Rsg3连锁。在两种1号生理小种抗性来源中鉴定出共同的分子标记，这表明要么这些植物中的抗尖镰孢菌基因成簇，要么这些位点是等位基因。在豇豆基因组内对抗性位点进行定位发现，3个与Rsg3和（或）994-Rsg连锁的标记位于第6连锁群上。
