Horticultural Crops Research and Development Institute, Peradeniya, Sri Lanka.
U.S. Department of Agriculture, Agricultural Research Service, Soybean Genomics and Improvement Laboratory, Beltsville Agricultural Research Center, Beltsville, MD 20705, U.S.A.
Plant Dis. 2023 Aug;107(8):2431-2439. doi: 10.1094/PDIS-08-22-1942-RE. Epub 2023 Aug 18.
Bean rust is a devastating disease of snap beans in Sri Lanka. Our study endeavored to develop snap beans with resistance to , the bean rust pathogen reported to have numerous virulent races. Accordingly, we needed a detailed understanding of the virulence of . and to identify genes conferring effective rust resistance. To investigate the virulence, we collected leaves of snap bean with rust symptoms from four snap bean producing districts of Sri Lanka. From these samples we established 57 single pustule isolates. Each isolate was inoculated on a set of 12 differential cultivars, six from the Andean and six from the Middle American gene pools of common bean. The virulence of the isolates segregated into four distinct groups that comprised the first four reported races of in Sri Lanka, 23-5, 31-1, 31-11, and 63-21. All races were significantly more virulent on the Andean than on the Middle American differential cultivars. PI 1819966, a Middle American differential cultivar containing the gene, conferred resistance to all four races. Three other Middle American cultivars were resistant to three races. Conversely, five Andean differential cultivars were susceptible to all four races. PI 160418 was the only Andean differential cultivar with resistance to three races. The results suggested that rust resistance genes from the Middle American differential cultivars could be combined in different ways with the resistance of Andean PI 260418 to develop snap bean varieties with broad resistance to all races of in Sri Lanka.
菜豆锈病是斯里兰卡青刀豆的一种毁灭性病害。本研究旨在培育对菜豆锈病病原菌具有抗性的青刀豆，该病原菌据报道具有许多毒力不同的小种。因此，我们需要详细了解菜豆锈病的毒力，并鉴定赋予有效锈病抗性的基因。为了调查毒力，我们从斯里兰卡四个青刀豆生产区收集了带有锈病症状的青刀豆叶片。从这些样本中，我们建立了 57 个单疱分离物。每个分离物都接种在一组 12 个差异品种上，其中 6 个来自安第斯基因库，6 个来自普通菜豆的中美洲基因库。分离物的毒力分为四个不同的组，包括斯里兰卡报告的前四个菜豆锈病小种，即 23-5、31-1、31-11 和 63-21。所有小种在安第斯差异品种上的毒力均显著高于中美洲差异品种。PI 1819966 是一种含有 基因的中美洲差异品种，对所有四个小种均具有抗性。其他三个中美洲品种对三个小种具有抗性。相反，五个安第斯差异品种对所有四个小种均敏感。PI 160418 是唯一对三个小种具有抗性的安第斯差异品种。结果表明，从中美洲差异品种中获得的锈病抗性基因可以与安第斯 PI 260418 的抗性以不同的方式结合，从而开发出对斯里兰卡所有菜豆锈病小种具有广泛抗性的青刀豆品种。
