Abstract:

This study investigated the pollination ecology and differences in breeding systems of three Meconopsis species with sympatric distribution on Jiajin Mountain. This study observed and statistically analyzed the flowering phenology and insect pollinators of Meconopsis integrifolia， Meconopsis henrici and Meconopsis punicea and used benzidine hydrogen peroxide and triphenyltetrazolium chloride （TTC） staining methods to detect stigma receptivity and pollen viability， respectively. The results indicated that： 1） The flowering period of M. integrifolia began about one month earlier than that of the M. henrici and the M. punicea， and the flowering periods of the latter two were similar， and the three had overlapping flowering periods. 2） The duration of stigma receptivity of the three Meconopsis species was more than 5 days， and the plant stigma receptivity was the strongest at the 3rd to 4th day of flowering. 3） Within 8 hours after dispersal， the pollen viability of M. integrifolia and M. henrici decreased with time， and the pollen viability of M. punicea initially increased and then decreased. 4） The pollen∶ovule of M. integrifolia pollen was 990±28， and that of M. henrici was 2050±596 （P<0.05）. The pollen∶ovule of M. punicea was intermediate （1380±202）， and not significantly different from the other two species. The three species of Meconopsis display facultative outcrossing. 5） Three species of Meconopsis had the same pollinator， Helicophagella melanura. M. integrifolia was the species visited by the largest number of insect species， while M. punicea attracted the highest total number of insect visits and M. henrici had the lowest total number of insect visits. The main pollinator of M. punicea was a small parasitic fly which only visits this species and lays its eggs on the stigma. In summary， there were differences among the three species in the breeding system： the flowering period and stigma receptivity period of M. integrifolia were the longest， with the strongest stigma receptivity and the highest number of pollinating insects， which compensated for the rapid decline in pollen viability； the pollen of M. henrici could maintain high viability for a long time， but the number of pollinating insects was the least； M. punicea has a unique pollination mode involving a small parasitic fly. They oviposit within the stigma and assist the host in intraspecific pollination， ensuring pollen reaches flowers of the same species.

Key words: Meconopsis, pollen viability, stigma receptivity, pollen-ovule ratio, pollinator, reproductive strategy