Environmental determinants of genetic diversity inCaragana microphylla(Fabaceae) in northern China

Abstract

The sand‐fixing shrub Caragana microphylla (Fabaceae) is extensively used for vegetation restoration in areas of northern China undergoing desertification. Although the understanding of its genetic variation and related determinants is an important component of plant conservation and ecological restoration in the face of a changing global environment, the relationship between genetic diversity in C. microphylla and climatic factors is unknown. In this study, we assessed population genetic variation in C. microphylla along temperature and humidity gradients in northern China using inter‐simple sequence repeat (ISSR) markers. In general, high levels of genetic diversity were uncovered in the 13 populations studied. The number of polymorphic loci ranged from 14 to 63 and polymorphism percentages ranged from 8.75 to 39.38%. Observed and effective allele numbers were 1.09–1.40 and 1.06–1.30, respectively. Nei's genetic diversity index (h) was calculated as 0.0340–0.1663 and Shannon's diversity index (I) was 0.0502–0.2403. At the species level, h and I were 0.2579 and 0.3965, respectively. Populations from low hydrothermal level areas, experiencing severe desertification and habitat fragmentation, exhibited the greatest genetic diversity. Genetic diversity in C. microphylla was positively correlated with annual temperature range, cold index, mean annual rainfall and hydrothermal synthesis index, whereas a negative association was found with mean annual temperature. Using redundancy analysis, we found that mean annual rainfall and cold index explained 87.8% of observed genetic variation, suggesting that genetic diversity in C. microphylla depends primarily on these two factors. Our data are relevant to the restoration and management of degraded ecosystems in arid and semiarid regions.

Effects of environmental factors on genetic diversity ofCaragana microphyllain Horqin Sandy Land, northeast China

“…Our study revealed that WI and SOP were the major environmental factors that affected genetic diversity indices of the 20 studied C. microphylla populations, which indicates that genetic variation in C. microphylla primarily depends on a greater than 5°C monthly mean temperature and SOP concentration. This result is not consistent with the previously reported relationship between ISSR diversity and environmental factors in C. microphylla from northern China (AP and CI were the major environmental factors that affected genetic diversity indices) (Huang et al., ). This suggests that AP and CI were the major environmental factors that affected genetic diversity indices in C. microphylla on the large‐scale field, and WI was the major environmental factors on the small‐scale field.…”

“…In C. microphylla , we calculated a value of 0.5041 for I ; this is higher than the mean I value for outcrossing species produced by Bussell (). Compared with previous study, all values of genetic diversity indices estimated in C. microphylla in Horqin Sandy Land are higher than those reported in northern China based on ISSR analysis (Huang et al., ). These differences came from scale difference, because of Horqin Sandy Land was the main natural distribution area of C. Microphylla .…”

“…If this is the case, what is the change trend and characteristics of genetic diversity within and among C. microphylla populations along environmental gradients across Horqin Sandy Land. Is there correlation between genetic diversity of C. microphylla and climatic factors in Horqin Sandy Land? If this is the case, whether consistent with previous findings (AP and CI were the major climatic factors that affected genetic diversity indices of C. microphylla populations from northern China; Huang et al., )? If not consistent, which one or several climatic factors affect genetic diversity of C. microphylla populations from Horqin Sandy Land, and how are they correlated? Is there correlation between genetic diversity of C. microphylla and soil factors in Horqin Sandy Land?…”

“…Caragana microphylla is long‐lived, perennial, insect‐pollinated, has seed‐based reproduction, and has a broad ecological amplitude (Fu, ). Previous studies on C. microphylla have focused on aspects of population distribution patterns and ecological adaptations (Zhao, ), morphological characteristics and variations (Li, Jiang, Gu, Ma, & Gao, ), physiological adaptations (Li et al., ; Ma, Gao, Liu, Wang, & Guo, ), nutrient absorption (Li, Chen, Cui, Zhao, & Zhang, ), and genetic diversity (Guo et al., ; Huang, Zhao, Zhao, Li, & Pan, ; Huang et al., ). However, the relationship between C. microphylla genetic diversity and environmental gradients has not yet been reported.…”

Evaluation of molecular diversity analysis and relation with environmental factors in accessions of Cumin (Cuminum cyminum L.) in Iran, revealed by inter-simple sequence repeat (ISSR) markers and start codon targeted (SCoT) markers

“…These results are in line with the relationship between genetic diversity and ecological parameters in Stipa grandis from Inner Mongolia (ZHAO et al, 2006). Also this point was considered by HUANG et al (2016) in Caragana microphylla (Fabaceae) with regard to relationships between climatic factors and genetic diversity that showed positive in uence of some climatic factors on genetic diversity. Similar to our results were reported in Artemisia halodendron (Asteraceae) that indicated by HUANG et al (2014).…”