Moya Patricia, Molins Arantzazu, Škaloud Pavel, Divakar Pradeep K, Chiva Salvador, Dumitru Cristina, Molina Maria Carmen, Crespo Ana, Barreno Eva
Botánica, Instituto Cavanilles de Biodiversidad y Biología Evolutiva (ICBIBE), Fac. CC. Biológicas, Universitat de València, Valencia, Spain.
Department of Botany, Faculty of Science, Charles University, Prague, Czechia.
Front Microbiol. 2021 Dec 24;12:765310. doi: 10.3389/fmicb.2021.765310. eCollection 2021.
The worldwide, ecologically relevant lichen-forming genus currently includes 41 accepted species, of which the group (PSULgp) and the group (PSAXgp) have received considerable attention over recent decades; however, phycobiont diversity is poorly known in s. lat. Here, we studied the diversity of microalgae associated with 159 thalli collected from 30 locations, including nine spp.: , and . The mycobionts were studied by carrying out phylogenetic analyses of the nrITS. Microalgae genetic diversity was examined by using both nrITS and LSU rDNA markers. To evaluate putative species boundaries, three DNA species delimitation analyses were performed on and . All analyses clustered the mycobionts into two main groups: PSULgp and PSAXgp. Species delimitation identified 13 fungal and 15 algal species-level lineages. To identify patterns in specificity and selectivity, the diversity and abundance of the phycobionts were identified for each species. High specificity of each group for a given clade was observed; PSULgp associated only with clade I and PSAXgp with clade S. However, the degree of specificity is different within each group, since the PSAXgp mycobionts were less specific and associated with 12 spp., meanwhile those of PSULgp interacted only with three spp. Variation-partitioning analyses were conducted to detect the relative contributions of climate, geography, and symbiotic partner to phycobiont and mycobiont distribution patterns. Both analyses explained unexpectedly high portions of variability (99 and 98%) and revealed strong correlations between the fungal and algal diversity. Network analysis discriminated seven ecological clusters. Even though climatic conditions explained the largest proportion of the variation among these clusters, they seemed to show indifference relative to climatic parameters. However, the cluster formed by A/ B/ sp. 2/ sp. S02/ sp. 3A was identified to prefer cold-temperate as well as humid summer environments.
全球范围内，具有生态相关性的地衣形成属目前包括41个公认物种，其中近几十年来，组（PSULgp）和组（PSAXgp）受到了相当多的关注；然而，在南纬地区，共生藻的多样性鲜为人知。在此，我们研究了从30个地点采集的159个地衣体中相关微藻的多样性，包括9种：、和。通过对nrITS进行系统发育分析来研究共生菌。利用nrITS和LSU rDNA标记检测微藻的遗传多样性。为了评估假定的物种界限，对和进行了三种DNA物种界定分析。所有分析将共生菌聚类为两个主要组：PSULgp和PSAXgp。物种界定确定了13个真菌和15个藻类物种水平的谱系。为了确定特异性和选择性模式，确定了每个地衣物种中共生藻的多样性和丰度。观察到每个地衣组对给定共生藻进化枝具有高度特异性；PSULgp仅与进化枝I相关，而PSAXgp与进化枝S相关。然而，每组内的特异性程度不同，因为PSAXgp共生菌的特异性较低，与12种共生，而PSULgp的共生菌仅与3种相互作用。进行了变异划分分析，以检测气候、地理和共生伙伴对共生藻和共生菌分布模式的相对贡献。两种分析都解释了出乎意料的高比例变异性（99%和98%），并揭示了真菌和藻类多样性之间的强相关性。网络分析区分了七个生态集群。尽管气候条件解释了这些集群间最大比例的变异，但它们似乎对气候参数表现出漠不关心。然而，由A/B/物种2/物种S02/物种3A形成的集群被确定为偏好寒温带以及湿润的夏季环境。
