Evaluation of environmental factors effect on the genetic diversity,
genetic structure and the potential distribution of Rhododendron
aureum Georgi under changing climate
Abstract
Understanding genetic variation and structure, adaptive genetic
variation and its relationship with environmental factors is of great
significance to understand how plants adapt to climate change and design
effective conservation and management strategies. The objective of this
study was to (I) investigate the genetic diversity and structure by AFLP
markers in 36 populations of R. aureum from northeast China, (Ⅱ) reveal
the relative contribution of geographical and environmental impacts on
the distribution and genetic differentiation of R. aureum; (Ⅲ) identify
outlier loci under selection and evaluate the association between
outlier loci and environmental factors and (Ⅳ) exactly calculate
development trend of population of R. aureum,as it is confronted with
severe climate change and to provide information for designing effective
conservation and management strategies. We found high genetic variation
(I = 0.584) and differentiation among populations (ΦST = 0.711) and
moderate levels of genetic diversity within populations of R. aureum. A
significant relationship between genetic distance and environmental
distance was identified, which suggested that the differentiation of
different populations was the caused by environmental factors. Using
BayeScan and Dfdist, 42 outlier loci identified and most of the outlier
loci are associated with climate or relief factors, suggesting that
these loci are linked to genes that are involved in the adaptability of
R. aureum to environment. Species distribution models (SDM) showed that
climate warming will cause a significant reduction of suitable area for
R. aureum especially under the RCP 85 scenario. Our results help to
understand the potential response of R. auruem to climatic changes, and
provide new perspectives for R. auruem resource management and
conservation strategies.