Foot Stems Of This Orchid Pollination Biology Research

The Orchidaceae are one of the most species-rich plant families and their floral diversity and pollination biology have long intrigued evolutionary biologists. Here I review the history of orchid pollination in the worldwide and the development in China. I also summarize the mechanisms of deception in orchids include generalized food deception, food-deceptive floral mimicry, brood-site imitation, shelter imitation, pseudoantagonism, rendezvous attraction and sexual deception.The study of pollination ecology of orchids could provide insights into understanding of some key questions of plant evolution, such as reproductive isolation of speciation, adaptive evolution and evolution of mating system. The terrestrial orchid Eria coronaria have a bright yellow spot on its labellum. The signals on the labellum probably play a very important role on attract pollinator. We estimate the yellow spot may attract pollinator and studied the pollination biology of E. coronaria during October - November of 2006 in the Yachang Nature Reserve, Guangxi Province, SW China.We Our observations showed that Apis cerana cerana (Hymenopterous, Apidae) was the only pollinator. Honeybees most directly landed on the yellow spot of the labellum and inserted their heads into the passage between column and labellum. The round side of anther cap enabled honeybees to enter the flowers easily. But when the honeybees tried to exit forcibly from the flowers, the only way is put away the section of the anther cap, and the movement of anther cap could pull the viscidium adhered to the mid-thorax. According to our observation and statistic, it is suggested that E. coronaria attracted the honeybees by the yellow spot on the labellum. Sympatric rewarding plant Pittosporum glabratum is particularly similar to the yellow spot on the labellum of E. coronaria in morphology and color, and this similarity may increase the probability that the E. coronaria deceive honeybees. Contrast and analyze the morphology of E. coronari and honeybee, the morphology of honeybee matches with the structure and anther cap mechanism of E. coronaria, pollinator effectiveness is very high. Breeding experiments showed that E. coronaria was self-compatible and there was no significant difference in reproductive success between self-pollination and cross-pollination. It was neither apomixes nor spontaneous autogamy. The pollination success of this species was dependent on pollinators. These results indicate that E. coronaria is highly self-compatible and the fruit production is pollen limited.More over, we summarized the pollination syndromes of subtribe Eriinae and compared with E. coronaria. Our conclusion show the diversity in Eriinae is high.