Bala Kanak, Gautam Naveen, Paul Bernard
Laboratoire des sciences de la Vigne, Institut Jules Guyot, Université de Bourgogne, BP 27877, Dijon, 21078, France.
Curr Microbiol. 2006 Feb;52(2):102-7. doi: 10.1007/s00284-005-0116-9. Epub 2006 Feb 8.
Pythium rhizo-oryzae sp. nov. was isolated from some soil samples taken in paddy fields in northeastern India. For quite a long time it was wrongly identified as Pythium catenulatum Mathews, because of the presence of numerous catenulate hyphal bodies. The sequencing of the ITS region of its nuclear ribosomal DNA and a close look at its morphological characters have now enabled us to describe it as a new species. This species is characterized by the absence of zoospores and sporangia, rarely formed aritheridia and oogonia, and the presence of chained and terminal hyphal bodies. The ITS region of its rDNA comprises 774 bases. This oomycete is closely related to the members producing a filamentous inflated type of sporangia like P. catenulatum Mathews, P. torulosum Coker & Paterson, and P. inflatum Mathews. The closest of all these is P. catenulatum. Taxonomic description of this new species and its comparison with related oomycetes, together with the sequence of the PCR amplified internal transcribed region (spacers ITS1, ITS2, and the gene 5.8S) of its rDNA are given here.
稻根腐霉新种从印度东北部稻田采集的一些土壤样本中分离得到。很长一段时间以来，由于存在大量链状菌丝体，它被错误地鉴定为链状腐霉。现在，通过对其核糖体DNA的ITS区域进行测序并仔细观察其形态特征，我们能够将其描述为一个新物种。该物种的特征是没有游动孢子和孢子囊，很少形成雄器和藏卵器，以及存在链状和末端菌丝体。其rDNA的ITS区域由774个碱基组成。这种卵菌与产生丝状膨大类型孢子囊的成员密切相关，如链状腐霉、串珠腐霉和膨胀腐霉。其中最接近的是链状腐霉。本文给出了这个新物种的分类描述及其与相关卵菌的比较，以及其rDNA的PCR扩增内部转录区域（间隔区ITS1、ITS2和基因5.8S）的序列。
