Cytological study on self and hybridization affinity in Dendrobium officinale.

Abstract

To investigate the biological mechanism of self and hybridization affinity in Dendrobium officinale, stigma characteristics and pollen tube growth after self-pollination and after intraspecific hybridization in D. officinale were studied using fluorescence microscopy. Results for self-pollination showed that the pollen germinated, and the pollen tube reached the style base close to the ovary at 1 h. The pollen tube entered the ovary after 4 h, and growth stopped after 8 h. The ovary atrophied after 72 h, and then the pollen tube disappeared. There was a slight difference between parents. For intraspecific hybridization, the pollen tube smoothly entered the ovary. Hypothetically, D. officinale was gametophytic and self-incompatible. These results could provide cytological evidence for studying self-incompatibility in D. officinale as well as a technical and theoretical basis for germplasm conservation, cross breeding, and selection of new cultivars of D. officinale.