Breeding system and pollination ecology of an endangered desert shrub endemic to northwestern China

Abstract

The breeding system and pollination ecology of Tamarix taklamakanensis, an endangered shrub occurring in sand dunes in the Taklamakan Desert, were examined by seven pollination treatments and observational studies in natural populations in 2019.The results showed that T. taklamakanensis exhibits an outcrossed breeding system that is dominated by insect‐pollination. It is largely self‐incompatible, with infrequent occurrence of anemophily, but relies strictly on pollinators in outcrossing. The pollen vitality could last about six days versus the stigma receptivity last about one day. Two effective pollinators were detected, and the peaks of visitation were 10:30–13:30, 16:30–17:30 and 18:30–19:30 h. Seed set by artificial cross‐pollination was significantly higher than natural pollination rates, and seed set for a population with high insect visitation rates was significantly higher than a population with low visitation rate, suggesting that pollen limitation is an important constraint on seed production for this species. Adverse weather conditions and habitat fragmentation were speculated to be the primary factors affecting the insect visitation of T. taklamakanensis in the Taklimakan Desert.