Adaptive fitness of Sapindus emarginatus Vahl populations towards future climatic regimes and the limiting factors of its distribution

Ashish Kumar Pal; Vivek Vaishnav; Baleshwar Meena; Nalini Pandey; Tikam Singh Rana

doi:10.1038/s41598-020-60219-8

Adaptive fitness of Sapindus emarginatus Vahl populations towards future climatic regimes and the limiting factors of its distribution

Sci Rep. 2020 Mar 2;10(1):3803. doi: 10.1038/s41598-020-60219-8.

Authors

Ashish Kumar Pal^{1

2}, Vivek Vaishnav¹, Baleshwar Meena¹, Nalini Pandey², Tikam Singh Rana³

Affiliations

¹ Plant Diversity, Systematics and Herbarium Division, CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow, 226001, India.
² Plant Nutrition and Stress Physiology Laboratory, Department of Botany, University of Lucknow, Lucknow, 226007, India.
³ Plant Diversity, Systematics and Herbarium Division, CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow, 226001, India. ranats@nbri.res.in.

Abstract

Sapindus emarginatus Vahl (Sapindaceae) also known as 'Indian Soap nut' is significantly important for saponin content in its fruits. However, its current population in India is heavily fragmented due to a lack of sustainable harvesting practices. Moreover, changing climatic regimes may further limit its distribution and possibly compromise the survival of the species in nature. The aim of the present study was to: predict the future distribution range of S. emarginatus; identify the bioclimatic variables limiting this distribution and to evaluate its adaptive fitness and genomic resilience towards these variables. To determine future species distribution range and identify limiting bioclimatic variables, we applied two different ecological niche models (ENMs; BioClim and MaxEnt) on real occurrence data (n = 88 locations). The adaptive fitness of the species was evaluated by quantifying the genetic variability with AFLP markers and marker-environmental associations, using AFLP-associated Bayesian statistics. We found 77% overlap between the baseline (2030) and predicted (2100) species distribution ranges, which were primarily determined by maximum temperature (T_MAX) and mean annual precipitation (MAP). The T_MAX and MAP contributed 43.1% and 27.1%, respectively to ENM model prediction. Furthermore, AFLP loci significantly associated with bioclimatic variables, and T_MAX and MAP represent the lowest proportion (6.15%), confirming to the severe response of the species genome towards these variables. Nevertheless, the very low Linkage disequilibrium (LD) in these loci (4.54%) suggests that the current sensitivity to T_MAX and MAP is subject to change during recombination. Moreover, a combination of high heterozygosity (0.40-0.43) and high within-population variability (91.63 ± 0.31%) confirmed high adaptive fitness to maintain reproductive success. Therefore, the current populations of S. emarginatus have substantial genomic resilience towards future climate change, albeit significant conservation efforts (including mass multiplication) are warranted to avoid future deleterious impacts of inbreeding depression on the fragmented populations.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adaptation, Physiological*
Climate Change*
Population Dynamics
Sapindus / physiology*