论文部分内容阅读
从进境的美国大豆豆秆样品中分离到2株疑似大豆茎褐腐病菌Phialophora gregata的分离物247-8和8300-5,2株分离物在PGM培养基上菌落圆形,边缘规则,白色至暗褐色,表面隆起,粗糙,轮纹状。分生孢子卵形至椭圆形,无色,平滑,单胞,平均大小4.3μm×1.9μm。分生孢子梗具有瓶梗状结构,无色,无隔膜或有隔膜,大小(5~16)μm×(2~3)μm,呈桶型或长颈瓶型。特异性引物BSRIGS1/2、BSR1/2和Pgl/4分别扩增分离物247-8的DNA得到预期1 022 bp、483 bp和499bp的产物;分离物8300-5的DNA经PCR扩增分别得到834 bp、483 bp和499 bp的预期条带。2株分离物的ITS区序列完全一致,与Gen Bank中大豆茎褐腐病菌(登录号AB190396、DQ459387、DQ459386和AF132804)的序列相似性为100%。人工接种大豆幼嫩植株茎基部均产生大豆茎褐腐病菌的典型症状。根据分离物形态特征、PCR检测、序列分析以及致病性测试结果,将进境美国大豆样品中的分离物247-8和8300-5鉴定为大豆茎褐腐病菌P.gregata。
Two isolates, 247-8 and 8300-5, of Phialophora gregata, which were suspected to be Soybean stalk rot, were isolated from the imported soybean samples of U.S. soybean. The colonies on the PGM medium were round, marginal and white To dark brown, surface uplift, rough, round grain. Conidia oval to oval, colorless, smooth, single cells, the average size of 4.3μm × 1.9μm. Conidiophores have the shape of bottle stem, colorless, no septum or septum, and the size is (5 ~ 16) μm × (2 ~ 3) μm. The specific primers BSRIGS1 / 2, BSR1 / 2 and Pgl / 4 were used to amplify the DNA of isolate 247-8 respectively to obtain the expected products of 1 022 bp, 483 bp and 499 bp. The DNA of isolate 8300-5 was obtained by PCR amplification respectively The expected bands of 834 bp, 483 bp and 499 bp. The ITS sequences of the two isolates were completely identical with those of GenBank accession Trichoderma longibrachiatum (Accession Nos. AB190396, DQ459387, DQ459386 and AF132804). Artificial inoculation of soybean young plant stem base to produce soybean Stem Rot pathogenic bacteria typical symptoms. Based on the morphological characteristics of the isolates, PCR analysis, sequence analysis and pathogenicity test results, the isolates 247-8 and 8300-5 entering the U.S. soybean samples were identified as P.gregata.