• The Plant Pathology Journal
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• 제19권6호
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• pp.269-273
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• 2003

A total of 57 isolates of Colletotrichum gloeosporioides were recovered from diseased tissues of Hall's crab apple (Malus haliana), 3 cultivars of edible apple (M. pumila var. dulcissima), red pepper (Capsicum annum), and grapevine (Vitis vinifera) fruits. All isolates showed strong virulence on their own host plants. Isolates from edible apple exhibited high level of cultivar specificity in pathogenicity tests. Ten isolates from apple cultivar 'Fuji' were virulent on 'Jonathan' and 'Rall's Genet'. However, 12 isolates from 'Jonathan' and 'Rall's Genet' were not virulent on 'Fuji'. Among the 24 isolates from red pepper, only seven and two isolates were infective on edible apple and grapevine fruits, respectively. All six isolates from grapevine were only virulent on their own host. These isolates were grouped into five vegetative compatibility groups (VCGs), A, B, C, D, and E, by demonstrating heterokaryosis through complementation using nitrate-nonutilizing (nit) mutants. Among them, isolates belong to VCG-A and VCG-D accounted for 24 and 17 isolates； those in VCG-A exhibited wide host range involving Hall's crab apple, all three edible apple cultivars, and red pepper. On the other hand, isolates of VCG-D and VCG-E showed limited host range specific to red pepper and grapevine, respectively. Taken together, the data suggest that among C. gloeosporioides isolates, the concepts of pathotype and/or forma specialis may exist, and that three is a relationship between host specificity and VCG grouping among C. gloeosporioides isolates.

• The Plant Pathology Journal
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• 제30권4호
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• pp.384-396
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• 2014

Vegetative compatibility groups (VCGs) are determined for many fungi to test for the ability of fungal isolates to undergo heterokaryon formation. In several fungal plant pathogens, isolates belonging to a VCG have been shown to share significantly higher genetic similarity than those of different VCGs. In this study we sought to examine the relationship between VCG and genetic similarity of an important cool season turfgrass pathogen, Sclerotinia homoeocarpa. Twenty-two S. homoeocarpa isolates from the Midwest and Eastern US, which were previously characterized in several studies, were all evaluated for VCG using an improved nit mutant assay. These isolates were also genotyped using 19 microsatellites developed from partial genome sequence of S. homoeocarpa. Additionally, partial sequences of mitochondrial genes cytochrome oxidase II and mitochondrial small subunit (mtSSU) rRNA, and the atp6-rns intergenic spacer, were generated for isolates from each nit mutant VCG to determine if mitochondrial haplotypes differed among VCGs. Of the 22 isolates screened, 15 were amenable to the nit mutant VCG assay and were grouped into six VCGs. The 19 microsatellites gave 57 alleles for this set. Unweighted pair group methods with arithmetic mean (UPGMA) tree of binary microsatellite data were used to produce a dendrogram of the isolate genotypes based on microsatellite alleles, which showed high genetic similarity of nit mutant VCGs. Analysis of molecular variance of microsatellite data demonstrates that the current nit mutant VCGs explain the microsatellite genotypic variation among isolates better than the previous nit mutant VCGs or the conventionally determined VCGs. Mitochondrial sequences were identical among all isolates, suggesting that this marker type may not be informative for US populations of S. homoeocarpa.

• 한국식물병리학회지
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• 제12권1호
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• pp.41-46
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• 1996

본 실험은 이병 딸기의 조직에서 분리 동정된 시들음병균(Fusarium oxysporum f. sp. fragariae) 균주들의 유？거 변이를 random amplified polymorphic DNA(RAPD) marker들을 이용하여 조사하였다. 총 24개의 딸기 시들음병 균주들의 DNA를 주형으로 하여 16개의 random 10-mer primer들을 사용하여 증폭시킨 결과 총 231개의 marker들을 이용하여 유전적 변이를 조사해 본 결과 크게 RAPD I과 RAPD II의 2개 그룹으로 나눌 수 있었다. RAPD I그룹에 속하는 균주는 VCG A에 속하는 Y1, K1, K2, K3, K4, N2, N3, N4-1, N6-1, N6-2, N8, N9, N10, M1-2-1 균주, VCG B에 속하는 M4-1 균주 그리고 VCG C에 속하는 N1, Y2 균주들이었고, RAPD II그룹에는 VCG B에 속하는 M1-1, M2-2-1, M2-4-2, M3-2, M3-3-2 균주와 VCG D에 속하는 N1 1 균주가 속하였다. 이들 2그룹 간에는 31%의 유사성이 있었다.