香蕉枯萎镰刀菌的核糖体DNA-ITS区段序列分析

寻找香蕉枯萎镰刀菌1号生理小种(Focr1)和4号生理小种(Focr 4)在rDNA-ITS区段序列上的差异,为香蕉枯萎镰刀菌小种的快速检测提供依据。对来自海南省和广东省的3个Focr 1和5个Focr 4菌株进行rDNA-ITS测序,并与GenBank中的4个尖孢镰刀菌的rD-NA-ITS序列进行比对分析。8个菌株中ITS1和ITS2分别为147和152 bp,与GenBank中的尖孢镰刀菌有97.0%~99.0%的同源性。香蕉枯萎镰刀菌4号生理小种和1号生理小种与GenBank中尖镰孢菌菊花专化型、尖孢镰刀菌黄瓜专化型和一品冠萎凋病菌在rDNA-ITS序列的367与386 bp位点存在两处共性差异:4号生理小种的碱基均为T(胸腺嘧啶),而1号生理小种和GenBank中3个菌株的碱基均为C(胞嘧啶)。尖孢镰刀菌rDNA-ITS区段序列不适于区分种内不同专化型及生理小种。

Sequence Analysis of Ribosomal DNA-ITS of Banana Fusarium wilt

The research aimed to seek the difference on rDNA-ITS sequence between Focr 1 and Focr 4 biological races of banana fusarium wilt and provide basis for rapid detection of banana fusarium wilt race.rDNA-ITS sequencing was conducted on 3 strains of Focr 1 and 5 strains of Focr 4 from Hainan province and Guangdong province and their sequencing results were compared with rDNA-ITS sequence of 4 Fusarium oxysporum on GenBank website.ITS1 and ITS2 of 8 strains were 147 and 152 bp respectively,which had 97.0%～99.0% homologies with 4 strains of F.oxyporum on GenBank website.Focr 4 and Focr 1 physiological races had 2 commonness differences on 367 bp and 386 bp sites of rDNA-ITS sequence of Chrysanthemi snyder et Hansen,F.oxysporumf.sp.Cucumerium and F.oxysporum Schl.F.cyclaminis Synder et Handen: base pairs in Focr 4 were all T(thymine) and those in Focr 1 and 3 strains on GenBank website were all C(cytosine).rDNA-ITS fragment sequence of F.oxysporum was not suitable for distinguishing intraspecies different specialized types and biological races.