Departamento de Biologia, Faculdade de Engenharia, Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), 15385-000, Ilha Solteira, São Paulo, Brazil.
Mycologia. 2002 May-Jun;94(3):437-49.
Anastomosis group 3 (AG-3) of Rhizoctonia solani (teleomorph = Thanatephorus cucumeris) is frequently associated with diseases of potato (AG-3 PT) and tobacco (AG-3 TB). Although isolates of R. solani AG-3 from these two Solanaceous hosts are somatically related based on anastomosis reaction and taxonomically related based on fatty acid, isozyme and DNA characters, considerable differences are evident in their biology, ecology, and epidemiology. However, genetic diversity among field populations of R. solani AG-3 PT and TB has not been documented. In this study, the genetic diversity of field populations of R. solani AG-3 PT and AG-3 TB in North Carolina was examined using somatic compatibility and amplified fragment length polymorphism (AFLP) criteria. A sample of 32 isolates from potato and 36 isolates from tobacco were paired in all possible combinations on PDA plus activated charcoal and examined for their resulting somatic interactions. Twenty-eight and eight distinct somatic compatibility groups (SCG) were identified in the AG-3 PT and AG-3 TB samples, respectively. AFLP analyses indicated that each of the 32 AG-3 PT isolates had a distinct AFLP phenotype, whereas 28 AFLP phenotypes were found among the 36 isolates of AG-3 TB. None of the AG-3 PT isolates were somatically compatible or shared a common AFLP phenotype with any AG-3 TB isolate. Clones (i.e., cases where two or more isolates were somatically compatible and shared the same AFLP phenotype) were identified only in the AG-3 TB population. Four clones from tobacco represented 22% of the total population. All eight SCG from tobacco were associated with more than one AFLP phenotype. Compatible somatic interactions between AG-3 PT isolates occurred only between certain isolates from the same field (two isolates in each of four different fields), and when this occurred AFLP phenotypes were similar but not identical.
茄腐皮镰孢菌（Rhizoctonia solani）的吻合群 3（AG-3）常与马铃薯病害（AG-3PT）和烟草病害（AG-3TB）相关。尽管来自这两种茄科植物宿主的茄腐皮镰孢菌 AG-3 分离株在体细胞吻合反应方面是相关的，在分类学上基于脂肪酸、同工酶和 DNA 特征也是相关的，但它们在生物学、生态学和流行病学方面存在明显差异。然而，尚未记录茄腐皮镰孢菌 AG-3PT 和 TB 田间种群的遗传多样性。在这项研究中，使用体细胞相容性和扩增片段长度多态性（AFLP）标准，检测了北卡罗来纳州茄腐皮镰孢菌 AG-3PT 和 AG-3TB 田间种群的遗传多样性。从马铃薯中采集了 32 个分离株，从烟草中采集了 36 个分离株，将它们在 PDA 加活性炭上进行所有可能的组合配对，并检查它们的体细胞相互作用。在 AG-3PT 和 AG-3TB 样本中分别鉴定出 28 个和 8 个不同的体细胞相容性组（SCG）。AFLP 分析表明，AG-3PT 中的 32 个分离株中的每一个都有独特的 AFLP 表型，而在 AG-3TB 的 36 个分离株中发现了 28 个 AFLP 表型。AG-3PT 分离株中没有一个与任何 AG-3TB 分离株在体细胞上相容或具有相同的 AFLP 表型。仅在 AG-3TB 种群中鉴定出克隆（即两个或多个分离株在体细胞上相容且具有相同的 AFLP 表型）。来自烟草的 4 个克隆占总群体的 22%。烟草的 8 个 SCG 都与不止一个 AFLP 表型相关。AG-3PT 分离株之间的体细胞相容仅发生在来自同一田间的某些分离株之间（在四个不同田间中的每个田间中都有两个分离株），并且当这种情况发生时，AFLP 表型相似但不完全相同。
