Effect of Polyploidy on Ecophysiology of Four-Wing Saltbush: Implications for its Sustainable Use in Agriculture and Degraded Land Reclamation

Abstract

This paper seeks to analyze the impact of ploidy level (chromosome size of cells) on drought tolerance of four-wing saltbush in its native habitat of western US with an aim to inform a more successful introduction of this species to arid region of Northern China. A suite of ecophysiological traits related to xylem water transport and drought tolerance were investigated in populations of three dominant cytotypes, i.e. diploid (2X), tetraploid (4X) and hexaploid (6X). The results show that four-wing saltbush of the three cytotypes have contrastingly different traits related to drought tolerance, which is related to their habitat differentiation in their native environment of western US. This study indicate that genetic variation related to ploidy change in four-wing saltbush is one basis for the adaptation of this species to heterogeneous environments with strong drought stress, which strongly suggests the importance of taking account genetic variation for the introduction of this species to arid regions with high environment heterogeneity.