Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China.
Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada.
Sci Rep. 2016 Mar 1;6:22434. doi: 10.1038/srep22434.
As highly prized, popular mushrooms, morels are widely distributed in the northern hemisphere, with China as a modern centre of speciation and diversity. Overharvesting of morels has caused concern over how to effectively preserve their biological and genetic diversity. However, little is known about their population biology and life cycle. In this study, we selected two sympatric phylogenetic species, Mel-13 (124 collections from 11 geographical locations) and Morchella eohespera (156 collections from 14 geographical locations), using fragments of 4 DNA sequences, to analyse their genetic structure. Our results indicated significant differentiation among geographic locations in both species, whereas no obvious correlation between genetic and geographic distance was identified in either species. M. eohespera exhibited a predominantly clonal population structure with limited recombination detected in only 1 of the 14 geographic locations. In contrast, relatively frequent recombination was identified in 6 of the 11 geographic locations of Mel-13. Our analysis indicated that the sympatric species Mel-13 and M. eohespera might have divergent evolutionary patterns, with the former showing signatures of recent population expansion and the latter being relatively stable. Interestingly, we found no heterozygosity but strong evidence for genealogical incongruence, indicating a high level of inbreeding and hybridisation among morel species.
作为备受推崇的流行蘑菇，羊肚菌广泛分布于北半球，中国是现代羊肚菌物种形成和多样性的中心。过度采集羊肚菌引起了人们对如何有效保护其生物和遗传多样性的关注。然而，人们对其种群生物学和生命周期知之甚少。在这项研究中，我们选择了两个共生的系统发育种，Mel-13（来自 11 个地理地点的 124 个样本）和 Morchella eohespera（来自 14 个地理地点的 156 个样本），使用 4 个 DNA 序列片段来分析它们的遗传结构。我们的研究结果表明，在这两个物种中，地理分布之间存在显著的分化，而在这两个物种中都没有发现遗传和地理距离之间的明显相关性。M. eohespera 表现出主要的无性种群结构，在仅有的 14 个地理地点中的 1 个地点中检测到有限的重组。相比之下，在 Mel-13 的 11 个地理地点中的 6 个地点中，相对频繁地发生了重组。我们的分析表明，共生种 Mel-13 和 M. eohespera 可能具有不同的进化模式，前者表现出最近种群扩张的特征，而后者相对稳定。有趣的是，我们发现没有杂合性，但有强烈的证据表明种系关系不一致，表明羊肚菌属物种之间存在高水平的近亲繁殖和杂交。
