Dichogamy and Style Curvature Avoid Self-Pollination in Eremurus altaicus

This paper gives a systematic study of Eremurus altaicus in terms of flowering characteristics, pollinating features, style movement pattern, stigma receptivity and mating system. The result showed that it was protandrous and that the stigma had no receptivity until the end of pollen dispersal. Its style showed a regular movement pattern during the flowering phase. The style was upright, very close to anthers at first; then it quickly curved down 90° from the base just before the dehiscing of anthers, but went back to the former upright state after pollen dispersal of all 6 anthers. From the blossoming to the end of pollen dispersal, the stigma was smooth and dry, and had no receptivity to pollens until the style went back to the upright state with papillae, and mucus appeared. The curving down movement of the style significantly widened the relative distance between the stigma and the dehiscing anthers. Therefore, protandry and style movement are double safeguard mechanisms for avoiding selfing and promoting outcrossing in Eremurus altaicus, which has important significance in its reproduction and evolution potential.