First Report of Pyrenophora seminiperda in Turkey and Greece.
First Report of Pyrenophora seminiperda in Turkey and Greece.
复制标题
土耳其和希腊的首次报告。
作者：
T. Stewart;P. Allen;Susan E. Meyer
Pyrenophora seminiperda (Brittleb. & D.B. Adam) Shoemaker (anamorph Drechslera Campanulata (Lév.) B. Sutton) 是一种多面性种子病原体，可导致一年生和多年生草本种子库的高死亡率以及轻微的叶斑病。目前报道的分布主要是阿根廷、澳大利亚、加拿大、埃及、新西兰、南非和美国的温带草原、沙漠和冬季谷物种植区(2)。 P. seminiperda 最初于 1800 年代中期在法国被描述，但最近没有来自东欧或亚洲的报道 (2)。 2008 年 5 月，我们在从土耳其收集的种子库样本中的种子上观察到了疑似 P. seminiperda 的东西。观察到疾病的证据是从种子中突出的宏观黑色子座。特征性的棒状子座是从土耳其棉花堡附近的一粒 Taeniatherum caput-medusae 种子和土耳其格雷梅附近的 Love Valley 的六颗雀麦种子中采集的。从希腊佩里萨获得了来自单个未分散的 B. tectorum 种子的额外收集品。通过评估 V8 琼脂培养物中九个分离株的形态特征，初步确定了病原体的身份。在 20°C、12 小时光周期下孵育 4 天后，培养物产生白色菌丝体。受伤后，菌丝体产生放射状的黑色棒状子座（2至8×0.4至0.9毫米）。这些产生带有新月形多细胞分生孢子（79至125微米长）的分支分生孢子梗。这些属性与 Shoemaker (4) 和 Campbell 等人描述的 P. seminiperda 的无性型一致。 (1).没有观察到有性型。通过核糖体 DNA 内转录间隔区 (ITS) 基因测序分析，确认了分离株为 P. seminiperda。获得的 ITS 序列与该物种的北美单倍型序列相同。爱谷分离株中的四个（代表性分离株：GQ168725、BPI 879142、NRRL 54032）与 HTA 单倍型（GQ168724）匹配，而其他四个（代表性分离株：GQ168736、BPI 879143、NRRL 54033）与 HTJ 单倍型匹配 （GQ168735）。来自希腊佩里萨的分离株 (GQ168728、BPI 879144、NRRL 54034) 与 HTC 单倍型 (GQ168727) 匹配。通过在培养物中产生分生孢子，每 50 颗种子向非休眠 B. tectorum 种子撒上 0.003 g 分生孢子接种物，并在 10/20°C 和 12 小时光周期下孵育 14 天，证实了几种 Love Valley 分离株的致病性。超过 90% 的接种种子会形成子座，观察到死亡率高达 34%。形态学相似性与 ITS 序列数据相结合，提供了半足拟蜥出现在土耳其和希腊的确凿证据。在这些国家发现的这种病原体表明，它可能在欧亚大陆广泛传播，并且可能通过 B. tectorum 的种子到达北美 (3)，而不是代表这种北美范围内重要杂草的新病原体。参考文献： (1) M. A. Campbell 等人。植物病理学。 52:448, 2003。 (2) R. W. Medd 等人。澳大利亚。植物病理学。 32:539, 2003。 (3) S. E. Meyer 等人。 Can J. 植物病理学。 30:525, 2008。 (4) R. A. 舒梅克。能。 J.博特。 44:1451，1966 年。
Pyrenophora seminiperda (Brittleb. & D.B. Adam) Shoemaker (anamorph Drechslera campanulata (Lév.) B. Sutton) is a generalist seed pathogen that can cause high mortality in the seed banks of annual and perennial grasses and a minor leaf spot disease. Its current reported distribution is mainly temperate grasslands, deserts, and winter cereal-growing regions in Argentina, Australia, Canada, Egypt, New Zealand, South Africa, and the United States (2). P. seminiperda was originally described in France in the mid-1800s, but there are no recent reports from eastern Europe or Asia (2). In May of 2008, we observed what appeared to be P. seminiperda on seeds from seed bank samples collected in Turkey. Evidence of disease was observed as macroscopic black stromata protruding from the seed. The characteristic club-shaped stromata were collected from a Taeniatherum caput-medusae seed near Pamukkale, Turkey and six Bromus tectorum seeds in Love Valley near Goreme, Turkey. An additional collection from a single undispersed B. tectorum seed was obtained from Perissa, Greece. Identity of the pathogen was tentatively established by evaluating morphological characteristics for nine isolates in V8 agar culture. After 4 days of incubation at 20°C with a 12-h photoperiod, the cultures produced white mycelium. Following wounding, the mycelium produced black, club-shaped stromata (2 to 8 × 0.4 to 0.9 mm) in a radial pattern. These produced branched conidiophores bearing crescent-shaped, multicellular conidia (79 to 125 μm long). These attributes are consistent with those of the anamorph of P. seminiperda as described by Shoemaker (4) and Campbell et al. (1). The teleomorph was not observed. The identity of the isolates as P. seminiperda was confirmed with ribosomal DNA internal transcribed spacer (ITS) genetic sequencing analysis. ITS sequences obtained were identical to sequences for North American haplotypes of this species. Four of the Love Valley isolates, (representative isolate: GQ168725, BPI 879142, NRRL 54032) matched the HTA haplotype (GQ168724), while the other four (representative isolate: GQ168736, BPI 879143, NRRL 54033) matched the HTJ haplotype (GQ168735). The isolate from Perissa, Greece (GQ168728, BPI 879144, NRRL 54034) matched the HTC haplotype (GQ168727). Pathogenicity of several Love Valley isolates was confirmed by producing conidia in culture, dusting nondormant B. tectorum seeds with 0.003 g of conidial inoculum per 50 seeds, and incubating for 14 days at 10/20°C with a 12-h photoperiod. Stromata developed on >90% of inoculated seeds and mortality as high as 34% was observed. Morphological similarities combined with ITS sequence data provide conclusive evidence that P. seminiperda occurs in Turkey and Greece. The discovery of this pathogen in these countries indicates that it may be widespread in Eurasia and that it could have arrived in North America on seeds of B. tectorum (3) rather than representing a novel pathogen for this important weed in its North American range. References: (1) M. A. Campbell et al. Plant Pathol. 52:448, 2003. (2) R. W. Medd et al. Australas. Plant Pathol. 32:539, 2003. (3) S. E. Meyer et al. Can J. Plant Pathol. 30:525, 2008. (4) R. A. Shoemaker. Can. J. Bot. 44:1451, 1966.