Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, China.
CAS Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Urumqi, China.
Plant Biol (Stuttg). 2019 Jul;21(4):706-714. doi: 10.1111/plb.12979. Epub 2019 Apr 3.
The moss Syntrichia caninervis is widely distributed in cool temperate and cold deserts where environmental pressures create a dependence on asexual reproduction (fragment reproduction). However, when compared to sporophyte-producing mosses, there is a lack of evidence to support the capacity of drought-tolerant mosses that predominantly fragment and produce protonema to disperse over long distances. We used 20 microsatellite loci to study genetic variation and structure in six populations (five natural populations and one population from a regeneration site) in three contrasting and widely separated regions of China. The genetic diversity and expected heterozygosity were lower in populations from the Tengger Desert than in populations from the other regions. Using PCoA, UPGMA and Structure analysis, the genetic grouping divided the three regions into three distinct groups. This may indicate that in regions where S. caninervis reproduces predominantly asexually, propagules are spread mainly by short-distance dispersal. The genetic diversity of the population from the regeneration site in the Tengger Desert was slightly higher than that of the nearby, naturally occurring population, and included some input from the Pamir Plateau almost 2,300 km to the west, suggesting long-distance dispersal of S. caninervis propagules across the region. Predominantly asexually reproducing populations of S. caninervis are mainly dependent on short-distance dispersal. Long-distance dispersal of S. caninervis propagules across the region is difficult. Establishment of populations with dominant asexual reproduction will eventually result in genetic differentiation.
犬尾藓广泛分布于凉爽的温带和寒冷的沙漠中，那里的环境压力使它们依赖于无性繁殖（碎片繁殖）。然而，与产生孢子的藓类植物相比，缺乏证据支持耐旱藓类植物的能力，这些植物主要通过碎片和产生原丝体来在长距离内分散。我们使用 20 个微卫星位点研究了中国三个截然不同且相距甚远的地区的六个种群（五个自然种群和一个再生地点种群）的遗传变异和结构。与其他地区的种群相比，腾格里沙漠的种群遗传多样性和预期杂合度较低。通过 PCoA、UPGMA 和结构分析，遗传分组将三个地区分为三个不同的组。这可能表明，在 S. caninervis 主要无性繁殖的地区，繁殖体主要通过短距离扩散传播。腾格里沙漠再生地点种群的遗传多样性略高于附近自然发生的种群，并且包含了来自近 2300 公里外的帕米尔高原的一些输入，表明 S. caninervis 繁殖体在整个地区的长距离扩散。主要无性繁殖的 S. caninervis 种群主要依赖于短距离扩散。S. caninervis 繁殖体在整个地区的长距离扩散是困难的。具有主要无性繁殖的种群的建立最终将导致遗传分化。
