Gale Liane Rosewich, Katan Talma, Kistler H C
USDA-ARS, Cereal Disease Laboratory, and Department of Plant Pathology, University of Minnesota, St. Paul 55108.
Department of Plant Pathology, ARO, The Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel.
Plant Dis. 2003 Dec;87(12):1433-1438. doi: 10.1094/PDIS.2003.87.12.1433.
Isolates of the tomato wilt pathogen Fusarium oxysporum f. sp. lycopersici, predominantly from commercial tomato fields in Florida and southwestern Georgia, were characterized using vegetative compatibility grouping (VCG), nuclear restriction fragment length polymorphism (RFLP), and virulence. All field isolates that could be grouped into VCG belonged to VCG 0033. This VCG was first described by Marlatt et al. in 1996 for isolates from northern Florida, Arkansas, and North Carolina. This study demonstrates that VCG 0033 is also widespread in central and southern Florida, in addition to southwestern Georgia, and also was found to be present in Puerto Rico. Population genetic and phylogenetic analyses of 121 isolates indicated that molecular diversity among VCG 0033 isolates was by far the highest in Manatee County, FL, suggesting it to be the probable center of origin of this relatively newly described VCG. Virulence tests with a subset of isolates identified all VCG 0033 isolates as race 3, although differences in aggressiveness were observed among tested isolates, independent of resistance genes in the differential cultivars. The widespread VCG 0030 of F. oxysporum f. sp. lycopersici was not present in our field collections. This was unexpected, as strains from Florida isolated prior to 1990 were predominantly VCG 0030. This would suggest that VCG 0033 has replaced VCG 0030 in recent years in commercial tomato fields of Florida and southwestern Georgia.
番茄枯萎病病原菌尖孢镰刀菌番茄专化型（Fusarium oxysporum f. sp. lycopersici）的分离菌株，主要来自佛罗里达州和佐治亚州西南部的商业番茄田，通过营养体亲和群（VCG）、核限制性片段长度多态性（RFLP）和毒力进行了特征分析。所有能够归入VCG的田间分离菌株都属于VCG 0033。这个VCG最早由Marlatt等人于1996年针对来自佛罗里达州北部、阿肯色州和北卡罗来纳州的分离菌株进行描述。本研究表明，除了佐治亚州西南部外，VCG 0033在佛罗里达州中部和南部也广泛存在，并且在波多黎各也有发现。对121个分离菌株进行的群体遗传和系统发育分析表明，VCG 0033分离菌株之间的分子多样性在佛罗里达州马纳蒂县是迄今为止最高的，这表明它可能是这个相对新描述的VCG的起源中心。对一部分分离菌株进行的毒力测试确定所有VCG 0033分离菌株为3号小种，尽管在测试的分离菌株之间观察到了侵袭力的差异，且与鉴别品种中的抗性基因无关。尖孢镰刀菌番茄专化型广泛存在的VCG 0030在我们的田间采集样本中不存在。这是出乎意料的，因为1990年之前从佛罗里达州分离的菌株主要是VCG 0030。这表明近年来在佛罗里达州和佐治亚州西南部的商业番茄田中，VCG 0033已经取代了VCG 0030。
