Ersek T, Schoelz J E, English J T
Department of Plant Pathology, University of Missouri, Columbia 65211.
Appl Environ Microbiol. 1994 Jul;60(7):2616-21. doi: 10.1128/aem.60.7.2616-2621.1994.
We used PCR to differentiate species in the genus Phytophthora, which contains a group of devastating plant pathogenic fungi. We focused on Phytophthora parasitica, a species that can infect solanaceous plants such as tomato, and on Phytophthora citrophthora, which is primarily a citrus pathogen. Oligonucleotide primers were derived from sequences of a 1,300-bp P. parasitica-specific DNA segment and of an 800-bp P. citrophthora-specific segment. Under optimal conditions, the primers developed for P. parasitica specifically amplified a 1,000-bp sequence of DNA from isolates of P. parasitica. Primers for P. citrophthora similarly and specifically amplified a 650-bp sequence of DNA from isolates of P. citrophthora. Detectable amplification of these specific DNA sequences required picogram quantities of chromosomal DNA. Neither pair of primers amplified these sequences with DNAs from other species of Phytophthora or from the related genus Pythium. DNAs from P. parasitica and P. citrophthora growing in infected tomato stem tissue were amplified as distinctly as DNAs from axenic cultures of each fungal species. This is the first report on PCR-driven amplification with Phytophthora species-specific primers.
我们使用聚合酶链反应（PCR）来区分疫霉属中的物种，该属包含一组具有破坏性的植物致病真菌。我们重点研究了寄生疫霉，它能感染番茄等茄科植物，以及柑橘褐腐疫霉，它主要是一种柑橘病原体。寡核苷酸引物源自一段1300碱基对的寄生疫霉特异性DNA片段和一段800碱基对的柑橘褐腐疫霉特异性片段的序列。在最佳条件下，为寄生疫霉设计的引物能特异性地从寄生疫霉分离物中扩增出一段1000碱基对的DNA序列。柑橘褐腐疫霉的引物同样能特异性地从柑橘褐腐疫霉分离物中扩增出一段650碱基对的DNA序列。检测到这些特定DNA序列的扩增需要皮克数量级的染色体DNA。这两对引物均不能用来自其他疫霉物种或相关腐霉属的DNA扩增出这些序列。在受感染的番茄茎组织中生长的寄生疫霉和柑橘褐腐疫霉的DNA，与每种真菌无菌培养物的DNA一样能被清晰地扩增。这是关于用疫霉物种特异性引物进行PCR驱动扩增的首次报道。
