Phytopathology. 2003 Mar;93(3):364-76. doi: 10.1094/PHYTO.2003.93.3.364.
ABSTRACT Diverse isolates of the soilborne wilt fungi Verticillium dahliae and V. albo-atrum were studied to understand the nature and origins of those infecting cruciferous hosts. All isolates from cruciferous crops produced microsclerotia, and the majority produced long conidia with a high nuclear DNA content; these isolates were divided into two groups by amplified fragment length polymorphism (AFLP) analysis. One group could be subdivided by other criteria such as rRNA sequences and mitochondrial DNA restriction fragment length polymorphism (RFLP) analysis. Two crucifer isolates were short spored and had a low nuclear DNA content. The results are consistent with the crucifer isolates being interspecific hybrids. The long-spored isolates are best regarded as amphihaploids (or allodiploids) with the AFLP groups probably each representing separate interspecific hybridization events. The short-spored crucifer isolates appear to be derived from interspecific hybrids and are here called 'secondary haploids'. Molecular evidence suggests that one parent in the crosses was similar to V. dahliae. The other parent of the amphihaploids seems to have been more similar to V. albo-atrum than to V. dahliae, but was distinct from all isolates of either species so far studied. The implications for the taxonomy of crucifer isolates are discussed and the use of the name V. longisporum, proposed elsewhere for just some of these isolates, is discouraged.
摘要 对土壤枯萎病菌Verticillium dahliae 和 V. albo-atrum 的多种分离株进行了研究，以了解感染十字花科宿主的那些分离株的性质和起源。所有来自十字花科作物的分离株都产生微菌核，并且大多数分离株产生具有高核 DNA 含量的长分生孢子；这些分离株通过扩增片段长度多态性 (AFLP) 分析分为两组。一组可以通过 rRNA 序列和线粒体 DNA 限制性片段长度多态性 (RFLP) 分析等其他标准进一步细分。两个十字花科分离株具有短孢子和低核 DNA 含量。结果与十字花科分离株是种间杂种一致。长孢子分离株最好被视为异源单倍体（或异源二倍体），AFLP 组可能代表单独的种间杂交事件。短孢子十字花科分离株似乎来自种间杂种，在这里称为“次生单倍体”。分子证据表明，杂交中的一个亲本与 V. dahliae 相似。异源单倍体的另一个亲本似乎与 V. albo-atrum 比与 V. dahliae 更相似，但与迄今为止研究的任何一种的所有分离株都不同。讨论了对十字花科分离株分类学的影响，并反对使用其他地方仅为其中一些分离株提出的名称 V. longisporum。
