Kreis Rachel A, Dillard Helene R, Smart Christine D
Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Geneva, NY 14456.
College of Agricultural and Environmental Sciences, University of California, Davis, CA 95616.
Plant Dis. 2016 Dec;100(12):2422-2426. doi: 10.1094/PDIS-03-16-0414-RE. Epub 2016 Sep 23.
Alternaria brassicicola is the causal agent of Alternaria leaf spot, a common disease of brassica crops in New York State. New York isolates of A. brassicicola were collected from a variety of brassica crops and locations to evaluate the population diversity and screen for fungicide sensitivity. Isolates were genotyped for 10 microsatellite loci and assayed for sensitivity to azoxystrobin, a quinone outside inhibitor fungicide. The New York State population of A. brassicicola was found to have high levels of genotypic diversity and the population was found to be in linkage disequilibrium. Based on in vitro assays, the effective concentrations of azoxystrobin reducing spore germination by 50% ranged from 0.22 to 14.12 μg/ml. In order to confirm the sensitivity of 47 isolates to azoxystrobin, the cytb gene was characterized and sequenced to determine whether any of the mutations known to confer resistance to azoxystrobin were present. The mutations F129L, G137R, and G143A were not detected in the isolates studied.
链格孢是链格孢叶斑病的病原菌，链格孢叶斑病是纽约州十字花科作物的常见病害。从纽约州的各种十字花科作物和不同地点采集了链格孢的分离株，以评估种群多样性并筛选对杀菌剂的敏感性。对分离株的10个微卫星位点进行基因分型，并检测其对醌外抑制剂杀菌剂嘧菌酯的敏感性。结果发现，纽约州的链格孢种群具有高度的基因型多样性，且该种群处于连锁不平衡状态。基于体外试验，使孢子萌发率降低50%的嘧菌酯有效浓度范围为0.22至14.12μg/ml。为了确认47个分离株对嘧菌酯的敏感性，对细胞色素b基因进行了表征和测序，以确定是否存在已知的赋予对嘧菌酯抗性的任何突变。在所研究的分离株中未检测到F129L、G137R和G143A突变。
