Peres N A, Harakava R, Carroll G C, Adaskaveg J E, Timmer L W
University of Florida, Gulf Coast Research and Education Center, Wimauma 33598.
Instituto Biológico, São Paulo, Brazil.
Plant Dis. 2007 May;91(5):525-531. doi: 10.1094/PDIS-91-5-0525.
Citrus black spot, caused by Guignardia citricarpa, is a serious fruit spot disease and is widely distributed in Asia, southern Africa, and South America, but does not occur in North America or the Mediterranean region. A nonpathogenic species, G. mangiferae, is cosmopolitan with a wide host range and can colonize citrus fruit and leaves saprophytically. Detection and identification of Guignardia spp. on citrus fruit is necessary for epidemiological, management, and regulatory purposes. In this study, we compared published and unpublished polymerase chain reaction primer sets for their specificity and sensitivity in the detection and differentiation of the two Guignardia spp. All primers evaluated successfully identified the two species using purified DNA from fungal cultures or mycelia as source materials. However, some primer sets were not highly effective in detecting G. citricarpa when DNA was extracted directly from single characteristic black spot lesions on fruit. Thus, new primer pairs for both species were designed from the internal transcribed spacer region that were highly sensitive and specific for detection of G. citricarpa using DNA recovered from single lesions on fruit by a rapid DNA extraction procedure.
柑橘黑点病由柑橘球座菌引起，是一种严重的果实斑点病害，广泛分布于亚洲、南部非洲和南美洲，但在北美或地中海地区未发生。一种非致病性物种芒果球座菌在全球广泛分布，寄主范围广泛，能在柑橘果实和叶片上腐生定殖。为了流行病学、管理和监管目的，对柑橘果实上的球座菌属进行检测和鉴定很有必要。在本研究中，我们比较了已发表和未发表的聚合酶链反应引物组在检测和区分这两种球座菌属时的特异性和灵敏度。所有评估的引物均使用来自真菌培养物或菌丝体的纯化DNA作为源材料成功鉴定了这两个物种。然而，当直接从果实上的单个特征性黑点病斑中提取DNA时，一些引物组在检测柑橘球座菌方面效果不佳。因此，利用快速DNA提取程序从果实上的单个病斑中回收的DNA，从内部转录间隔区设计了对两种菌都适用的新引物对，这些引物对在检测柑橘球座菌时具有高度的敏感性和特异性。
