Tredway L P
Department of Plant Pathology, North Carolina State University, Raleigh 27695.
Plant Dis. 2006 Dec;90(12):1531-1538. doi: 10.1094/PD-90-1531.
Isolates of Magnaporthe poae from turfgrass hosts were analyzed for mating type, genetic relatedness according to ITS sequences, reaction to a previously developed species-specific poly-merase chain reaction (PCR) assay, and virulence on two creeping bentgrass cultivars in growth chamber experiments. Analysis of internal transcribed spacer (ITS) sequences revealed three clades, designated A, B, and C. Clade A contained isolates of both mating types from creeping bentgrass, annual bluegrass, and Kentucky bluegrass. Clade B contained only mating type 'A' isolates from annual bluegrass, whereas Clade C contained only mating type 'a' isolates from creeping bentgrass. The M. poae PCR assay failed to positively identify several North Carolina isolates from annual bluegrass and creeping bentgrass. M. poae isolates from Kentucky blue-grass were most virulent toward creeping bentgrass in growth chamber experiments. Although isolates of M. poae are not host specific, certain ITS clades may have a limited host or geographical range. The improved creeping bentgrass cv. Penn A-4 was more susceptible to summer patch than cv. Penncross. Additional research is needed to develop methods for accurate diagnosis of summer patch and other patch diseases in creeping bentgrass and to determine how creeping bentgrass cultivars vary in their susceptibility to these root pathogens.
对从草坪草寄主分离得到的早熟禾炭疽病菌株进行了交配型分析、基于ITS序列的遗传相关性分析、对先前开发的物种特异性聚合酶链反应（PCR）检测的反应分析，以及在生长室试验中对两个匍匐翦股颖品种的致病性分析。内部转录间隔区（ITS）序列分析揭示了三个进化枝，分别命名为A、B和C。进化枝A包含来自匍匐翦股颖、一年生早熟禾和草地早熟禾的两种交配型的分离株。进化枝B仅包含来自一年生早熟禾的交配型“A”分离株，而进化枝C仅包含来自匍匐翦股颖的交配型“a”分离株。早熟禾炭疽病菌的PCR检测未能阳性鉴定出一些来自一年生早熟禾和匍匐翦股颖的北卡罗来纳州分离株。在生长室试验中，来自草地早熟禾的早熟禾炭疽病菌株对匍匐翦股颖的致病性最强。虽然早熟禾炭疽病菌的分离株不是寄主特异性的，但某些ITS进化枝可能具有有限的寄主或地理范围。改良的匍匐翦股颖品种Penn A-4比Penncross品种更容易感染夏季斑病。需要进一步研究以开发准确诊断匍匐翦股颖夏季斑病和其他斑块病的方法，并确定匍匐翦股颖品种对这些根部病原菌的易感性如何变化。
