Conservation of genetic diversity in slippery elm (Ulmus rubra) in Wisconsin despite the devastating impact of Dutch elm disease

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• 作者：Johanne Brunet ; Juan Zalapa ; Raymond Guries
• 关键词：Dutch elm disease ; Slippery elm ; Ulmus rubra ; Genetic diversity ; Genetic structure ; Bottleneck
• 刊名：Conservation Genetics
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：17
• 期：5
• 页码：1001-1010
• 全文大小：792 KB
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Biomedicine
  Human Genetics
  Animal Anatomy, Morphology and Histology
  Plant Sciences
  Evolutionary Biology
  
• 出版者：Springer Netherlands
• ISSN：1572-9737
• 卷排序：17

文摘

Forest pest epidemics are responsible for many population declines reported in forest trees. While forest tree populations tend to be genetically diverse, in principle mortality resulting from disease could diminish that genetic diversity and alter the genetic structure of the remnant populations with consequences for the ability of a species to adapt to changing environments. Slippery elm (Ulmus rubra Muhl.) is a long-lived, wind-pollinated forest tree with a native range covering essentially all of eastern North America. Dutch elm disease (DED) caused by an introduced fungal pathogen (Ophiostoma ulmi) devastated North American elm populations, including slippery elm, beginning in the 1930s. Estimates of the numbers of elms lost to DED are unknown but range into the hundreds of millions of trees given their former abundance. In this study, the genotypes of 77 herbarium specimens collected between 1890 and 2004 in Wisconsin, and of 100 slippery elm trees from five wild Wisconsin populations, were characterized using 13 microsatellite loci. Levels of genetic diversity were compared between the herbarium specimens collected pre- and post-DED spread in Wisconsin. In addition, the levels of genetic diversity and degree of genetic differentiation were quantified in the five wild populations. The allelic diversity and expected levels of heterozygosity were similar between the pre- and post-DED herbarium specimens. The five wild populations were only slightly differentiated and no genetic bottleneck was detected for any population. At least in Wisconsin, slippery elm apparently has maintained levels of genetic diversity that could facilitate adaptation to future climatic and environmental changes.