Estación Biológica de Doñana, CSIC, Américo Vespucio s/n, 41092 Seville, Spain.
Mol Phylogenet Evol. 2013 Aug;68(2):161-75. doi: 10.1016/j.ympev.2013.04.003. Epub 2013 Apr 11.
Metschnikowia (Saccharomycetales, Metschnikowiaceae/Metschnikowia clade) is an ascomycetous yeast genus whose species are associated mostly with angiosperms and their insect pollinators over all continents. The wide distribution of the genus, its association with angiosperm flowers, and the fact that it includes some of the best-studied yeasts in terms of biogeography and ecology make Metschnikowia an excellent group to investigate a possible co-radiation with angiosperm lineages. We performed phylogenetic analyses implementing Bayesian inference and likelihood methods, using a concatenated matrix (≈2.6 Kbp) of nuclear DNA (ACT1, 1st and 2nd codon positions of EF2, Mcm7, and RPB2) sequences. We included 77 species representing approximately 90% of the species in the family. Bayesian and parsimony methods were used to perform ancestral character reconstructions within Metschnikowia in three key morphological characters. Patterns of evolution of yeast habitats and divergence times were explored in the Metschnikowia clade lineages with the purpose of inferring the time of origin of angiosperm-associated habitats within Metschnikowiaceae. This paper presents the first phylogenetic hypothesis to include nearly all known species in the family. The polyphyletic nature of Clavispora was confirmed and Metschnikowia species (and their anamorphs) were shown to form two groups: one that includes mostly floricolous, insect-associated species distributed in mostly tropical areas (the large-spored Metschnikowia clade and relatives) and another that comprises more heterogeneous species in terms of habitat and geographical distribution. Reconstruction of character evolution suggests that sexual characters (ascospore length, number of ascospores, and ascus formation) evolved multiple times within Metschnikowia. Complex and dynamic habitat transitions seem to have punctuated the course of evolution of the Metschnikowiaceae with repeated and independent origins of angiosperm-associated habitats. The origin of the family is placed in the Late Cretaceous (71.7 Ma) with most extant species arising from the Early Eocene. Therefore, the Metschnikowiaceae likely radiated long after the Mid-Cretaceous radiations of angiosperms and their diversification seems to be driven by repeated radiation on a pre-existing diverse resource.
毕赤酵母属（子囊菌门，毕赤酵母科/毕赤酵母分支）是一个子囊菌酵母属，其物种主要与各大洲的被子植物及其昆虫传粉者相关联。该属分布广泛，与被子植物花朵有关联，并且包括一些在生物地理学和生态学方面研究最好的酵母，这使得毕赤酵母属成为研究与被子植物谱系可能共同辐射的绝佳群体。我们使用核 DNA（ACT1、EF2 的第一和第二密码子位置、Mcm7 和 RPB2）序列的串联矩阵（约 2.6 Kbp），通过贝叶斯推断和似然方法进行了系统发育分析。我们包括了 77 个代表该科约 90%物种的种。使用贝叶斯和简约法在毕赤酵母属内的三个关键形态特征中进行了祖先特征重建。在毕赤酵母属的谱系中探索了酵母生境的进化模式和分歧时间，目的是推断出在毕赤酵母科内与被子植物相关的生境的起源时间。本文提出了第一个包含该科几乎所有已知种的系统发育假设。已确认克拉夫斯孢酵母的多系性，并且毕赤酵母属（及其无性型）被证明形成两个组：一个组包括主要分布在热带地区的花生的、昆虫相关的物种（大孢子毕赤酵母属和相关物种），另一个组包括在生境和地理分布方面更为多样的物种。特征进化的重建表明，有性特征（子囊孢子长度、子囊孢子数量和子囊形成）在毕赤酵母属内多次进化。复杂和动态的生境转换似乎打断了毕赤酵母科的进化过程，多次独立起源于与被子植物相关的生境。该科的起源被置于晚白垩世（71.7 Ma），大多数现存物种起源于始新世早期。因此，毕赤酵母科可能在中生代中期被子植物辐射之后很久才辐射，并且其多样化似乎是由对先前存在的多样化资源的多次辐射驱动的。
