Úrbez-Torres J R, Leavitt G M, Guerrero J C, Guevara J, Gubler W D
Department of Plant Pathology, University of California, Davis 95616.
University of California Cooperative Extension, Madera 93637.
Plant Dis. 2008 Apr;92(4):519-529. doi: 10.1094/PDIS-92-4-0519.
Perennial cankers and consequent grapevine dieback are a major problem in vineyards of Sonora and Baja California, the most important grape-production areas of Mexico. In order to identify the canker-causing agents, symptomatic arms, cordons, and trunks were collected from 13 and 6 vineyards in Sonora and Baja California, respectively. Two Botryosphaeriaceae spp., Lasiodiplodia theobromae and Diplodia seriata, were isolated frequently from infected wood and identified based on morphological and cultural characters as well as analyses of nucleotide sequences of three genes, the internal transcribed spacer region (ITS1-5.8S-ITS2), a partial sequence of the β-tubulin gene, and part of the translation elongation factor 1-α gene (EF1-α). Although both L. theobromae and D. seriata were isolated from grapevine cankers in Baja California, only L. theobromae was found in vines in the Sonora region. Pathogenicity of both species was verified by inoculation of rooted cuttings and green shoots of Thompson Seedless and Chardonnay cultivars. Isolates of L. theobromae were more virulent, based on the extent of spread in the secondary wood and green tissue, than those of D. seriata. These findings confirm L. theobromae and D. seriata as the causal agents of dieback and canker formation of grapevines in northern Mexico.
多年生溃疡病及随之而来的葡萄树枯死是墨西哥最重要的葡萄产区索诺拉州和下加利福尼亚州葡萄园的一个主要问题。为了鉴定引起溃疡病的病原体，分别从索诺拉州的13个葡萄园和下加利福尼亚州的6个葡萄园采集了有症状的枝蔓、主蔓和树干。两种葡萄座腔菌科真菌，可可毛色二孢和葡萄座腔菌，经常从受感染的木材中分离出来，并根据形态和培养特征以及三个基因（内转录间隔区（ITS1-5.8S-ITS2）、β-微管蛋白基因的部分序列和翻译延伸因子1-α基因（EF1-α）的部分序列）的核苷酸序列分析进行鉴定。虽然在下加利福尼亚州的葡萄溃疡病中同时分离到了可可毛色二孢和葡萄座腔菌，但在索诺拉地区的葡萄树中只发现了可可毛色二孢。通过接种无核白和霞多丽品种的生根插条和嫩梢，验证了这两种菌的致病性。基于在次生木质部和绿色组织中的扩展程度，可可毛色二孢的分离株比葡萄座腔菌的分离株毒性更强。这些发现证实了可可毛色二孢和葡萄座腔菌是墨西哥北部葡萄树枯死和溃疡形成的病原体。
