Fungal Ecology ( IF 2.9 ) Pub Date : 2019-11-30 , DOI: 10.1016/j.funeco.2019.100878 Joseph Luiso , Katrin Kellner , Alix E. Matthews , Ulrich G. Mueller , Jon N. Seal
Lower diversity at range margins of expanding populations is thought to reduce host-symbiont specificity of obligate symbioses. Selection for relaxed symbiont recognition systems is thought to occur when most, if not all, symbionts available to a host are genetically similar. This study evaluated whether the genetic diversity of symbiont populations along a range margin (North America) were lower than those of Neotropical populations in fungus gardening ants (subtribe Attina). Using phylogenetic, population-genetic and community-ecology approaches, we tested the hypotheses that North American fungal populations are genetically less diverse than Neotropical populations and whether they exhibit evidence of recent population expansion. Results indicated that fungal diversity is somewhat greater in the Neotropics than North America; however, North American populations are very diverse because all lineages found in the Neotropics are also represented in North America. Moreover, we found evidence of recent population expansion in both the Neotropics and North America.
中文翻译:
最北端的Trachymyrmex和Mycetomoellerius蚂蚁种生长的真菌对北美的高度多样性和多重入侵
人们认为,在不断扩大的种群范围边缘处较低的多样性会降低专性共生体的寄主共生体特异性。人们认为,当宿主可利用的大多数(即使不是全部)共生体在遗传上相似时,就会选择轻松的共生体识别系统。这项研究评估了在一定范围边缘(北美)共生菌种群的遗传多样性是否低于真菌园艺蚂蚁(亚提纳族)的新热带种群的遗传多样性。使用系统发育,种群遗传和社区生态学方法,我们检验了以下假设:北美真菌种群的遗传多样性不及新热带种群,并且它们是否表现出近期种群扩张的证据。结果表明,新热带地区的真菌多样性比北美要大一些。然而,北美人口非常多样化,因为新热带地区发现的所有血统也都在北美有代表。此外,我们发现新热带地区和北美地区最近人口膨胀的证据。