Nitzan N, Tsror Lahkim L, Johnson D A
Department of Plant Pathology, Washington State University, Pullman 99164-6430.
Department of Plant Pathology, Agriculture Research Organization, Gilat Experiment Station, M. P. Negev, 85280, Israel.
Plant Dis. 2006 Oct;90(10):1287-1292. doi: 10.1094/PD-90-1287.
The vegetative compatibility of 123 isolates of Colletotrichum coccodes from North America (United States and Canada) originating from potato, tomato, pepper, and mint was tested using nitrate-nonutilizing (nit) mutants. The North American isolates did not anastomose with previously selected European/Israeli vegetative compatibility group (VCG) testers; therefore, eight isolates were selected as VCG testers for the North American population. The 123 isolates distributed to seven VCGs at 1.6, 1.6, 4.0, 8.1, 13.8, 19.5, and 36.6%, with 14.6% of the isolates not assigned to any of the seven VCGs. Among the North American (NA)-VCGs, the average frequency of the nit1/nit3 nit mutants was lower (P < 0.05) for isolates belonging to NA-VCG1 than for isolates belonging to the NA-VCGs 2, 3, and 5. In contrast, the frequency of NitM nit mutants did not vary (P > 0.05) among the NA-VCGs and was collectively 5.14%. The results also indicated significant (P < 0.05) differences among NA-VCGs and European/Israeli (EU/I)-VCGs regarding the frequency of nit mutants. The aggressiveness trials of the North American isolates to potato indicated that plants infected with isolates belonging to NA-VCG2 and NA-VCG5 had more (P < 0.05) sclerotia on the roots and crowns than plants infected with isolates belonging to NA-VCGs 1 and 3. The plants infected with isolates belonging to NA-VCG2 had sclerotia formed higher (P < 0.05) up the stem than the plants infected with isolates belonging to NA-VCGs 1, 3, or 5. The plants infected with isolates assigned to NA-VCG2 had more (P < 0.05) infected progeny tubers than the plants infected with isolates belonging to NA-VCGs 1, 3, or 5; and the plants infected with isolates belonging to NA-VCGs 1, 2, and 5 yielded fewer (P < 0.05) potato tubers than the noninoculated control plants. A naming system for the population of C. coccodes based on the continent source of the population, the VCG number, and the isolate's code was suggested.
利用硝酸盐不利用（nit）突变体对来自北美（美国和加拿大）的123株源自马铃薯、番茄、辣椒和薄荷的可可毛色链霉菌分离株的营养体亲和性进行了测试。北美分离株与先前选定的欧洲/以色列营养体亲和群（VCG）测试菌株不发生融合；因此，选择了8株分离株作为北美群体的VCG测试菌株。123株分离株分布在7个VCG中，比例分别为1.6%、1.6%、4.0%、8.1%、13.8%、19.5%和36.6%，有14.6%的分离株未归入这7个VCG中的任何一个。在北美（NA）-VCG中，属于NA-VCG1的分离株的nit1/nit3 nit突变体平均频率低于（P<0.05）属于NA-VCG2、3和5的分离株。相比之下，NitM nit突变体的频率在NA-VCG之间没有差异（P>0.05），总体为5.14%。结果还表明，NA-VCG和欧洲/以色列（EU/I）-VCG在nit突变体频率方面存在显著（P<0.05）差异。北美分离株对马铃薯的侵染试验表明，感染属于NA-VCG2和NA-VCG5的分离株的植株根部和冠部的菌核比感染属于NA-VCG1和3的分离株的植株更多（P<0.05）。感染属于NA-VCG2的分离株的植株茎上形成菌核的位置比感染属于NA-VCG1、3或5的分离株的植株更高（P<0.05）。感染归入NA-VCG2的分离株的植株比感染属于NA-VCG1、3或5的分离株的植株有更多（P<0.05）受感染的后代块茎；并且感染属于NA-VCG1、2和5的分离株的植株比未接种的对照植株结出的马铃薯块茎更少（P<0.05）。提出了一种基于群体的大陆来源、VCG编号和分离株代码的可可毛色链霉菌群体命名系统。
