Biological characteristics of flowers and examination of pollen viability at different developmental stages of Epimedium sagittatum( Sieb. et Zucc. )Maxim

Abstract

To gain a deeper understanding of the flowering pattern and reproductive characteristics of Epimedium sagittatum, to enrich the research on the flower development of Epimedium sagittatum and its reproductive regulation, and to screen the methods suitable for the rapid detection of pollen viability of Epimedium sagittatum and to promote its cross-breeding. The characteristics of its flower parts were observed, recorded and measured, and the pollen viability of Epimedium sagittatumwas determined by five methods, including TTC staining, I2-KI staining, red ink staining, peroxidase method and in vitro germination method. The flowering process of Epimedium sagittatum can be divided into five stages: calyx dehiscence, bract spathe, petal outgrowth, pollen dispersal, and pollination and withering. The results of I2-KI staining and peroxidase method were significantly higher than those of other methods; the in vitro germination method was intuitive and accurate, but the operation was complicated and time-consuming; the red ink staining method was easy to operate and had obvious staining effect, and the results were the closest to those of the in vitro germination method; and it was found that the pollen of Epimedium sagittatum was not as effective as the in vitro germination method at the bud stamen stage, the flower stigma and the flower bud. It was also found that the pollen viability and germination rate of Epimedium sagittatum pollen were higher in the three periods of bud spitting, petal adductor and pollen dispersal. Comparing the five methods, the red ink staining method was found to be a better method for the rapid detection of pollen viability; the best pollination periods of Epimedium sagittatum were the bud stamen stage, petal adductor stage, and pollen dispersal stage of flowers at the peak of bloom. This study on the flowering and fruiting pattern of Epimedium sagittatum, and the related mechanism of sexual reproduction, can be used as a reference for the next step of research on the breeding of Epimedium sagittatum.