埃里砖格孢属真菌的研究进展及展望

Progress and prospect in studies on Embellisia

埃里砖格孢属设立于1971年,由于具有重要经济价值的菌种不多,而研究较少。但随着一些重要病原菌和内生真菌在该属中的相继发现,近年来越来越多地受到重视。为便于今后开展相关研究,本研究就其形态学、生物学、生理学、生态学及经济意义等方面的研究进展进行了综述,并对将来可能进行的研究进行了展望。埃里砖格孢属真菌的形态特征与蠕形菌类(长蠕孢属、弯孢菌属、凹脐蠕孢属等)和暗色丝分砖格孢子类真菌(匍柄霉属、密格孢属、假格孢属、顶格孢属、链格孢属和单格孢属等)具有很多相似之处,但分生孢子具有宽而厚的隔膜是其最主要的鉴定依据。目前报道23个种,分布在各式各样的生境下,其中21个种分布在13个科的植物根际、根部或茎叶上,我国有5个种。本属中具有重要经济意义的种有2类,一类为植物病原菌,影响大蒜、风信子等作物产量和品质,或引起沙打旺草地早衰;另一类为疯草内生真菌,增加疯草(Astragalusspp.,Oxytropisspp.)毒性,导致家畜中毒。疯草内生真菌可产生的具有重要医用价值的苦马豆素。分子生物学技术已证明埃里砖格孢具有多态性,与匍柄霉亲缘关系比与假格孢属、链格孢和单格孢的亲缘关系远。控制疯草内生真菌的毒害是畜牧业生产中亟待解决的问题。埃里砖格孢的遗传多样性分析、新种寻找和有性态研究,以及苦马豆素的产生机制等研究将是近期主要的研究方向。

There has been little attention or intensive study of the genus Embellisia Simmons in the 30 years since the genus was established in 1971. However, there is now much interest in it as some important plant pathogens and plant endophytes have been found in recent years. This paper summaries the literature, morphology, biology, physiology, ecology and economic value of the genus and discusses prospects for further studies. Thick and dark conidial septa are the most diagnosing characteristics, and Embellisia is morphologically similar to Helminthosporium, Curvularia, Drechslera etc and also to dematiaceous dictyo-mitosporic fungi such as Sternphylium, Acrodictys, Nirnbya, Gibbage, Alternaria and Ulocladium. Twenty three species have been described from various habitats with 21 species found in plant rhizospheres, roots, stems and leaves. Five species have been reported from China. Two groups of Embellisia are of importance： one is plant pathogens which decrease production and quality of Alliurn satibum, Haycinthus orientalls, or promote degradation of Astragalus adsurgens pastures; the other is plant endophytes which increase toxicity of locoweed （Astragalus spp. , Oxytropis spp. ） and result in poisoning of livestock. However, the endophytes can produce swainsonine which can be used in treatment of some human diseases. Molecular biology studies have shown that Embellisia spp. are poly-morphic and genetically closer to Nimbya, Alternaria, and Ulocladium than to Stemphyliumn. In the future, toxicosis of livestock caused by the locoweed endophyte must be controlled. New species of Embellisia should be sought, the genetic diversity and teleomorph of Embellisia studied, and the genetics and production mechanism of swainsonie in the endophytic Embellisia elucidated as steps towards better economic utilization of this genus.