Self-Pollinated Types and Ecological Adaptations of the Desert Plant Gymnocarpos przewalskii

In desert plants, outcrossing is frequently limited by pollinator scarcity, leading to a certain percentage of self-fertilization. However, research on the ecological adaptations of self-fertilized seeds remains limited. <i>Gymnocarpos przewalskii</i> Maxim, a Tertiary relict plant in the arid deserts of Northwest China, exhibits pronounced self-pollination. In this study, the population of <i>G. przewalskii</i> from the fifth regiment of Alar City was selected to explore its self-pollination types, self-pollination percentages, and ecological adaptations. We found that artificially cross-pollinated <i>G. przewalskii</i> produced heavier seeds, faster germination, seedlings with greater biomass, and stronger environmental adaptability than self-pollination. However, the frequency of insect visits per flower was less than one. The fruit setting rate of natural pollination was 6.90%, while that of self-pollination was 4.43%, accounting for 64.20% of the natural fruit setting rate. Additionally, <i>G. pzewalskii</i>'s filaments elongated rapidly to make the anthers and stigma at the same height before flowering. These characteristics suggest that <i>G. przewalskii</i> is capable of autonomous self-pollination and is prior selfing. <i>Gymnocarpos przewalskii</i> likely produces a high proportion of the selfing merely to ensure population survival. These findings offer valuable insights into the adaptation of desert plants to the scarcity of pollinators.