野生食用菌“苇菇”的物种多样性及中华美味蘑菇适生区预测

Diversity of the‘reed mushrooms’and prediction of potential geographic distribution of Agaricus sinodeliciosus

“苇菇”是主产于新疆的野生食用菌,主要分布于我国西北内陆湖泊周边的芦苇或多枝柽柳林内,埋生或半埋生在土壤中。本研究共采集和收集相关标本91份,开展了形态学和分子系统学研究,结果表明这些宏观形态特征相似的“苇菇”标本并非一个物种,而是分属于蘑菇属Bivelares组的大肥蘑菇Agaricus bitorquis、中华美味蘑菇A.sinodeliciosus和亚托柄蘑菇A.subperonatus;及Nigrobrunnescentes组的帕达纳蘑菇A.padanus。本文对“苇菇”形态进行了描述,并提供了它们的分种检索表。其中大肥蘑菇、亚托柄蘑菇和帕达纳蘑菇在我国和欧洲等地均有分布,而中华美味蘑菇仅在我国有报道。据此,依据1950–2000年生物气候数据结合中华美味蘑菇的分布实地调查结果,利用最大熵模型(maximum entropy model,MaxEnt)开展了对中华美味蘑菇分布区的分析和预测,结果表明中华美味蘑菇适生区在我国主要为新疆天山山脉南北两侧、西藏西南部、青海海西州、甘肃西北部以及内蒙古西部地区;预测国外适生区域在中亚的哈萨克斯坦和蒙古国。物种分布模型涉及的环境变量对模型的贡献率显示,最湿月降水量、最暖季度降水量、最冷季度平均温度和最暖月最高温是影响中华美味蘑菇分布的主要环境因子。研究结果表明中华美味蘑菇适生区域狭窄,为狭域种,建议应加强相关资源的保护,并积极拓展其可持续利用途径以降低对野生中华美味蘑菇子实体的过度消耗。

The‘reed mushrooms’are general designation of wild edible fungi grown with Phragmites australis or Tamarix ramosissima in lakeside and mainly distributed in Xinjiang.In this study,ITS1-5.8S-ITS2(ITS)sequences were used to assess species delimitation of the specimens of‘reed mushroom’collected from Xinjiang.Combined with morphological examination,four species of Agaricus,i.e.A.bitorquis,A.padanus,A.sinodeliciosus,and A.subperonatus were recognized.The morphological descriptions,photos,and ITS for each species,as well as the dichotomous key were given.Maximum likelihood phylogenetic analysis of 55 ITS sequences from GenBank and 91 newly generated sequences in this study were performed.The four species from Xinjiang were well supported in the ITS tree.Voucher specimens were deposited in the Mycological Herbarium,Institute of Microbiology,Chinese Academy of Sciences,Beijing(HMAS).The geographical distribution data and correlating environmental factors of A.sinodeliciosus were used to model potential distribution using the maximum entropy model(MaxEnt).The highly suitable growing regions of A.sinodeliciosus were relatively limited,mainly located in northwestern China and Central Asia.In China,it is mainly distributed in the two sides of Tianshan Mountains,southwestern Tibet,Haixi State of Qinghai,northwestern Gansu,and western Inner Mongolia.The most effective environmental factors,namely the precipitation of wettest month,the precipitation of warmest quarter,the mean temperature of coldest quarter and the maximum temperature of warmest month,had decisive influence upon distribution of the species.Due to limited suitable region of A.sinodeliciosus growth,the protection should be strengthened and sustainable utilization approaches should be developed.