Viji G, Uddin W, O'Neill N R, Mischke S, Saunders J A
Department of Plant Pathology, The Pennsylvania State University, University Park 16802.
United States Department of Agriculture-Agricultural Research Service, Beltsville Agricultural Research Center, Beltsville, MD 20705.
Plant Dis. 2004 Nov;88(11):1269-1276. doi: 10.1094/PDIS.2004.88.11.1269.
Sixty-seven isolates of Sclerotinia homoeocarpa, causing dollar spot disease in creeping bentgrass, annual bluegrass, Bermudagrass, and perennial ryegrass turf, collected from 23 golf courses in various geographical regions of the United States and Canada between 1972 and 2001, were characterized by vegetative compatibility, genetic diversity, and pathogenicity. Eleven vegetative compatibility groups (VCGs A to K) were identified among the isolates tested in this study, and five of them (VCGs G to K) were new. VCG B was the most predominant group, typifying 33 isolates (51%) tested. S. homoeocarpa isolates collected from golf courses in Pennsylvania belonged to seven VCGs (A, B, E, F, G, I, and K), whereas three groups were observed in those collected from New York (B, E, and G) and New Jersey (E, H, and I). Two isolates, one each from Pennsylvania and Canada, were incompatible when paired with the tester isolates in all possible combinations, and did not fall into any known VCG. An isolate collected from Canada was compatible with tester isolates from two VCGs (C and D). Genetic analyses using amplified fragment length polymorphism (AFLP) showed the presence of two genetically distinct groups, designated as major group and the minor group. The major group included 36 isolates collected from various golf courses in the United States and Canada. Two isolates collected from bermudagrass in Florida formed a separate cluster, the minor group. Isolates that belonged to the major group were further divided into two subgroups (1 and 2). Subgroup 1 consisted of all the isolates that belonged to VCGs A, E, G, H, and I. Three of the four isolates that belonged to VCG K also were clustered with isolates of subgroup 1. Subgroup 2 consisted of all the isolates from VCG B, and one each from VCGs F and K. Pathogenicity assays on Penncross creeping bentgrass showed significant differences (P = 0.05) in virulence among the isolates. Overall, a relationship between virulence and VCGs was observed, in which certain virulence groups corresponded to specific VCGs; however, such a relationship was not observed between virulence and AFLPs. Close similarity among isolates of S. homoeocarpa collected from different locations in the United States and Canada suggests that isolates of the same genotype could be involved in outbreaks of dollar spot epidemics at multiple locations.
1972年至2001年间，从美国和加拿大不同地理区域的23个高尔夫球场采集了67株引起匍匐翦股颖、一年生早熟禾、狗牙根和多年生黑麦草草坪美元斑病的禾谷核盘菌菌株，对其进行了营养体亲和性、遗传多样性和致病性分析。在本研究测试的菌株中鉴定出11个营养体亲和群（VCG A至K），其中5个（VCG G至K）是新的。VCG B是最主要的群体，在测试的33株菌株（51%）中占主导。从宾夕法尼亚州高尔夫球场采集的禾谷核盘菌菌株属于7个VCG（A、B、E、F、G、I和K），而从纽约（B、E和G）和新泽西州（E、H和I）采集的菌株中观察到3个群体。来自宾夕法尼亚州和加拿大的两株菌株，在与测试菌株进行所有可能组合配对时均不亲和，且不属于任何已知的VCG。从加拿大采集的一株菌株与来自两个VCG（C和D）的测试菌株亲和。使用扩增片段长度多态性（AFLP）进行的遗传分析表明存在两个遗传上不同的群体，分别称为主要群体和次要群体。主要群体包括从美国和加拿大不同高尔夫球场采集的36株菌株。从佛罗里达州狗牙根采集的两株菌株形成一个单独的聚类，即次要群体。属于主要群体的菌株进一步分为两个亚组（1和2）。亚组1由所有属于VCG A、E、G、H和I的菌株组成。属于VCG K的4株菌株中的3株也与亚组1的菌株聚类。亚组2由所有来自VCG B的菌株以及来自VCG F和K的各一株菌株组成。对Penncross匍匐翦股颖进行的致病性测定表明，菌株间毒力存在显著差异（P = 0.05）。总体而言，观察到毒力与VCG之间存在关系，其中某些毒力组对应于特定的VCG；然而，在毒力与AFLP之间未观察到这种关系。从美国和加拿大不同地点采集的禾谷核盘菌菌株之间的密切相似性表明，相同基因型的菌株可能参与多个地点的美元斑病流行爆发。
