Genetic differentiation of black saxaul, Haloxylon aphyllum (Chenopodiaceae), along a soil salinity gradient in the Kyzylkum Desert

Abstract

Populations of Haloxylon aphyllum in the Kyzylkum Desert have been found to be markedly deficient in heterozygotes at a medium level of genetic diversity (P95 = 0.56, A = 1.67, Ho = 0.14, He = 0.28). Spatial genetic differentiation of these populations have been revealed along a soil salinity gradient (from 0 to 0.5 mmol Na+/g), with their genetic diversity reaching a maximum (Ho = 0.21–0.25, He = 0.25–0.27) in areas with a moderate salinity level (0.05–0.1 mmol Na+/g). Locus Got-2 can serve as a marker of this differentiation (FstGot-2 = 0.4).