分离自蔬菜地的腐霉一新种及其rDNAITS序列分析(英文)

A new Pythium species isolated from vegetable fields and analysis by rDNA ITS sequence

从广西南宁收集的蔬菜地土壤样本中,分离得到一个新的腐霉种,命名为广西腐霉Pythium guangxiense。不同于其近似种,广西腐霉的孢子囊球形或亚球形;藏卵器球形、亚球形、椭圆形或囊形;雄器同丝生或异丝生,柄常分枝且缠绕藏卵器。对构成广西腐霉rDNAITS区段的772个碱基进行扩增和测序。在根据ITS序列建立的分子系统发育树中,广西腐霉与禾生腐霉Pythium graminicola、周雄腐霉P.periilum和肿囊腐霉P.inflatum等产生瓣状孢子囊的腐霉种关系密切。对广西腐霉进行了分类描述和其与近似种的比较。

Pythium guangxiense sp.nov.,isolated from vegetable fields in Nanning,Guangxi,China,was described as a new species.It was distinguished from other similar species by the presence of spherical or subspherical sporangia,spherical,subspherical,oval or sac-like oogonia and the monoclinous and diclinous antheridia with often branched stalks twining round the oogonia.The ITS region of rDNA consisted of 772 bases was amplified and sequenced.This new species was closely related to the members producing filamentous inflated sporangia such as Pythium graminicola,P.periilum and P.inflatum on a phylogenetic tree established based on ITS sequences.Taxonomic description and comparison with relative species were made.