葛拟锈病菌rDNA-ITS的序列分析

分别从罹拟锈病的野葛Pueraria lobata(Willd.)Ohwi、粉葛P.thomsonii Benth.和山葛P.montana(Lour.)Merr.获得病原物拟锈病菌(集壶菌)Synchytrium sp.的孢子囊堆,用其作材料进行了不同DNA提取方法的效果比较,同时对来自以上3种不同植物菌株的核糖体DNA(rDNA)-ITS进行了克隆和序列分析.结果表明:改良的氯化苄法提取基因组DNA的效率最高,但单孢子囊直接进行PCR扩增也可以满足ITS的克隆和分析;来源于野葛和粉葛菌株的ITS1-5.8S-ITS2分别为856 bp和907 bp,两者同源性为92%;而山葛菌株的ITS1-5.8S-ITS2为1 148 bp,与野葛和粉葛菌株的同源性分别为54%和55%.由此推断,粉葛与野葛上的菌株可能为相同种的不同变种,而山葛上的菌株为另一个种;或者3种植物上的菌株分别为3个不同的集壶菌种.

rDNA-ITS Sequence Analysis of Synchytrium puerariae on Pueraria spp.

Four different DNA extraction methods were used to obtain genomic DNA of Synchytrium sp.from the sori isolated from Pueraria lobata(Willd.) Ohwi,P.thomsonii Benth.,P.montana(Lour.) Merr..The modified method using benzyl chloride is the most efficient one to extract genomic DNA.rDNA-ITS can be successfully amplified directly from a single sporangium by PCR.The ITS sequence length of the isolates from P.lobata and P. thomsonii are 856 bp and 907 bp respectively shared 92% sequence similarity; the ITS sequences from P.montana are 1 148 bp,with 54% and 55% sequence similarity to the isolates from P.lobata and P.thomsonii respectively.The results indicated that the isolates from P.lobata and P.thomsonii are different varieties of the same species or two closely related species and the isolates from P.montana are another species of Synchytrium,or a more distantly related species.