红菇科可食真菌的若干分类问题

红菇科Russulaceae包含大量全球广泛采食的野生食用菌,同时也有一定数目的毒菌。该科特别是红菇属的分类是大型真菌分类的难点。近年来DNA数据大量应用于红菇科的分类,更新了属的界定和概念,发现了大量新物种,为食用菌和毒菌的识别和鉴定带来了可用的名称。然而,DNA证据并不总是与形态证据吻合,这又为食用菌和毒菌的识别和名称的使用带来了困扰和不便。本文针对乳菇属、多汁乳菇属和红菇属中的重要食用菌类群,回顾了近年来的分类研究进展,分析了研究背后的数据实情和存在的分类问题。认为：在食用菌和毒菌的确定上,依靠物种复合群共有的形态特征更具有可操作性;依据DNA序列进行的劈分式分类和依靠少数样品的特征及DNA序列上的少量差异发表新种的做法可能产生不便于使用的后果;在乳菇属和红菇属中,“BLAST相似度低的即为新种”的分类实践存在错误风险;充分结合历史资料和各个类群的特点,确定物种划分的阈值,才能有望解决红菇科真菌的分类问题。

Taxonomic comments on edible species of Russulaceae

The family Russulaceae includes a large number of edible species collected and consumed worldwide and some poisonous ones. The family, especially the genus Russula is notoriously difficult in taxonomy. Application of DNA data to the taxonomic studies updates the limits and concepts of its constituent genera and uncovers an increasing number of new species. This brings available names for identification of edible and poisonous species, but simultaneously causes confusion and inconvenience when using the new and amended names due to discordance between molecular and morphological evidences. Focusing on several important edible groups of Russulaceae, this paper reviews the most recent progresses in the taxonomy of Russulaceae, analyzes the data supporting the studies and gives comments on the taxonomic issues. The author concludes that morphological approach is more feasible in identifying edible or poisonous species if shared characters within a species complex are fully understood. Splitting taxonomy using only DNA data and describing new species with insufficient sampling and few changes in sequence data may have unpractical taxonomic outcomes. In the taxonomic practice of Lactarius and Russula, “low similarity in BLAST equal to new species” has a risk of producing synonyms. To achieve a thoroughly resolved taxonomy, full reference to historical documents and setting appropriate cutoffs when delimitating species by respecting the personality of each group is needed.