Study on the Characteristics of Pollination Biology of Dipsacus asperoides

PurposeTo study the pollen viability, stigma receptivity, flower visiting insects and pollen grain shape of Dipsacus asperoides, and to determine the pollination biology of it.

MethodsUsing two kinds of D. asperoides with white and purple anther as experimental materials, the pollen viability was determined by TTC method, I₂-KI method and peroxidase method; the stigma receptivity was determined by benzidine-hydrogen peroxide method; the developmental changes of stigma were recorded and observed manually, and the species and number of flower visiting insects were counted; the morphological structure of pollen grain was observed by electron microscopy.

ResultsD. asperoides had the highest pollen vitality on the day of flowering, and the highest pollen vitality appeared at 14: 00, after which the pollen vitality gradually decreased. The stigma began to be receptive on the 3rd day of flowering, and reached the maximum on the 5th to 6th day, indicating that D. asperoides was heterogynous and male precocious. Flower visiting insects mainly included bees, butterflies, flies and more than a dozen other insects. Bees were the main pollinators, and flower visiting peaks occured at 11: 30-12: 30 and 16: 00. The anthers of D. asperoides were strip shaped, the pollen grains had three germination holes. They were nearly spherical and equal polar pollen grains, belonging to large pollen grains. The pollen surface was covered with spiny protrusions.

ConclusionThe results can lay a theoretical foundation for the development of improved variety breeding, cross breeding and efficient cultivation measures of D. asperoides.