重要卵菌綱植物病原菌之分類與鑑定

Abstract

卵菌(oomycetes)主要的生物特徵是會產生卵圓形的休眠孢子(卵孢子)以及游動的孢子(游走子)，雖然遺傳親緣關係和某些藻類相近，但無葉綠素無法行光合作用且形態與部分生物特性(菌絲)則與真菌類似，故又稱類真菌 (pseudofungi)。卵菌綱(Oomycetes)有⼀些成員是重要的植物病原菌，造成農業上的經濟損失或生態上的景觀破壞，這些植物病原卵菌(⼀千多種)多數屬於露菌目(Peronosporales)，⼀些屬於⽩銹菌目(Albuginales)，以及少數屬於水霉目(Saprolegniales)。隨著分子生物技術的發展，這3 個目的植物病原卵菌的分類地位因時代與分類系統有所差異，有些舊有的屬種被重新分類或分拆，也有更多的新種被發現與命名。現今植物病原卵菌的鑑定方法除了傳統上依據形態特徵之外，核酸序列親緣關係的重要性更是日益提升，故形態特徵與核酸序列親緣關係便成了卵菌分類與鑑定的重要依據。 Although oomycetes are phylogenetically close to some algae, some of their morphology and biological characteristics are similar to fungi. So, they are also called pseudo-fungi. Some members of the Oomycetes are important plant pathogens, causing economic losses in agriculture or damage to the landscape plants. Most of the pathogenic oomycetes (more than one thousand species) belong to the Order Peronosporales, some to the Order Albuginales, and a few to the Order Saprolegniales. Conventionally, morphology is the basic characters for oomycetes classification and identification. However, with the development of molecular biotechnology, the taxonomic systems of plant pathogenic oomycetes were modified frequently in the decades. Some old genera and species were split or reclassified, and more new species were discovered and named. In addition to the morphological characteristics, the phylogeny of nucleic acid sequences supports precise information for the identification of plant pathogenic oomycetes. Therefore, morphological characteristics and molecular phylogeny are essential for the classification and identification of plant pathogenic oomycetes.