Clonality, local population structure and gametophyte sex ratios in cryptic species of the Sphagnum magellanicum complex
Clonality, local population structure and gametophyte sex ratios in cryptic species of the Sphagnum magellanicum complex
复制标题
麦哲伦泥炭藓复合体隐秘物种的克隆性、当地种群结构和配子体性别比例
DOI：
10.1093/aob/mcad077
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发表时间：
2023
期刊：
影响因子：
4.2
通讯作者：
Piatkowski, Bryan
中科院分区：
文献类型：
--
作者：
Shaw, A. Jonathan;Duffy, Aaron M.;Nieto-Lugilde, Marta;Aguero, Blanka;Schuette, Scott;Robinson, Sean;Loveland, James;Hicks, Karen A.;Weston, David;Piatkowski, Bryan
泥炭藓属（Sphagnum）是苔藓（Bryophyta）的一个分支，约有300-500种.该属具有无与伦比的生态重要性，因为泥炭藓占主导地位的泥炭地储存了近三分之一的陆地碳库，泥炭工程师泥炭地的形成和微地形。泥炭藓的基因组资源正在积极扩大，但其生物学的许多方面仍然知之甚少。其中包括泥炭藓属物种无性繁殖的程度，以及这些单倍体占优势的植物中雄配子体和雌配子体的相对频率。我们评估了克隆性和配子体性别比，并测试了关于北美四种S.麦哲伦复合体这四个物种在形态上很难区分，并且非常接近。我们还评估微生物群落与泥炭藓宿主植物克隆和性别在两个sites. MethodsFourhundred和5个样品的四个物种，代表57个种群，进行限制性内切酶位点相关的DNA测序（RADseq）。基于分子数据的群体结构和克隆性分析采用了系统发育和表型方法。使用RADseq数据鉴定多基因座基因型（基因）。性别的采样分株确定使用分子的方法，利用覆盖率的性染色体上的基因座的方法进行验证后，使用的植物样品，表达性别表型。估计每个物种和物种内的种群的性别比。以每个株系所包含的分株数来估计株系间的适合度差异。程度的克隆性[基因/分株（样品）的数量]种内，网站之间，和配子体性别之间进行了估计。估计每个物种的性别比，和种群内species. Sphagnum相关的微生物群落进行了评估，在两个网站有关tophagnumclonality和sex.Key ResultsAll四个物种似乎从事混合性和无性（克隆）繁殖。大多数属为一个分株，但也有个别属为2 ~ 8个分株。在多个居群中，只有一个基群由分株代表;所有其他基群仅限于一个居群。在种群内分株的个别基因在空间上聚集，这表明有限的分散，即使在泥炭地。在其它3个物种中，除S. divinum外，其余3个物种的性比均表现为雌性偏向，但在S. diabolicum中表现为雄性偏向。无论是物种，也没有男性/女性不同的克隆繁殖水平。在瑞吉斯湖（纽约州）和富兰克林沼泽（VT），微生物群落组成的网站之间有很大的差异，但物种，基因和性别之间的差异没有检测到。在S. divinum，然而，女性配子体窝藏两到三倍的微生物类群的男性。Conclusions这四个泥炭藓物种都表现出类似的生殖模式，从有性和无性生殖的混合物的结果。克隆复制分株的基因组的空间格局表明，这些物种之间的所谓的方阵模式，在那里的基因组彼此邻接，但不广泛混合，因为有限的分株碎片，游击队模式，广泛的基因组碎片化和分散的结果，在更大的混合不同的基因组。虽然性别比例在…
Background and AimsSphagnum(peatmoss) comprises a moss (Bryophyta) clade with ~300–500 species. The genus has unparalleled ecological importance becauseSphagnum-dominated peatlands store almost a third of the terrestrial carbon pool and peatmosses engineer the formation and microtopography of peatlands. Genomic resources forSphagnumare being actively expanded, but many aspects of their biology are still poorly known. Among these are the degree to whichSphagnumspecies reproduce asexually, and the relative frequencies of male and female gametophytes in these haploid-dominant plants. We assess clonality and gametophyte sex ratios and test hypotheses about the local-scale distribution of clones and sexes in four North American species of theS. magellanicumcomplex. These four species are difficult to distinguish morphologically and are very closely related. We also assess microbial communities associated withSphagnumhost plant clones and sexes at two sites.MethodsFour hundred and five samples of the four species, representing 57 populations, were subjected to restriction site-associated DNA sequencing (RADseq). Analyses of population structure and clonality based on the molecular data utilized both phylogenetic and phenetic approaches. Multi-locus genotypes (genets) were identified using the RADseq data. Sexes of sampled ramets were determined using a molecular approach that utilized coverage of loci on the sex chromosomes after the method was validated using a sample of plants that expressed sex phenotypically. Sex ratios were estimated for each species, and populations within species. Difference in fitness between genets was estimated as the numbers of ramets each genet comprised. Degrees of clonality [numbers of genets/numbers of ramets (samples)] within species, among sites, and between gametophyte sexes were estimated. Sex ratios were estimated for each species, and populations within species.Sphagnum-associated microbial communities were assessed at two sites in relation toSphagnumclonality and sex.Key ResultsAll four species appear to engage in a mixture of sexual and asexual (clonal) reproduction. A single ramet represents most genets but two to eight ramets were dsumbers ansd text etected for some genets. Only one genet is represented by ramets in multiple populations; all other genets are restricted to a single population. Within populations ramets of individual genets are spatially clustered, suggesting limited dispersal even within peatlands. Sex ratios are male-biased inS. diabolicumbut female-biased in the other three species, although significantly so only inS. divinum. Neither species nor males/females differ in levels of clonal propagation. At St Regis Lake (NY) and Franklin Bog (VT), microbial community composition is strongly differentiated between the sites, but differences between species, genets and sexes were not detected. WithinS. divinum, however, female gametophytes harboured two to three times the number of microbial taxa as males.ConclusionsThese fourSphagnumspecies all exhibit similar reproductive patterns that result from a mixture of sexual and asexual reproduction. The spatial patterns of clonally replicated ramets of genets suggest that these species fall between the so-called phalanx patterns, where genets abut one another but do not extensively mix because of limited ramet fragmentation, and the guerrilla patterns, where extensive genet fragmentation and dispersal result in greater mixing of different genets. Although sex ratios in …