Study On The Reproductive Interference Of Two Sympatric Primula (Primuaceae)

Reproduction is a key question of evolution, plants have evolved a variety of reproductive strategies to achieve reproductive success. But the reproductive success of plants are affected by many factors, especially for those who are pollinated by the animals, reproductive success was mediated by pollinators. In the long-term evolutionary process, plants-pollinators mutualisms are very important. Of these, specialized pollination have played a very good security for plant reproduction. But in overall, generalized pollination is more common that highly evolve for pollinator sharing which will bring interspecific competition and interspecific interference. In particular, for those sympatric, flowering time overlap and pollinator sharing plants are inevitable. To reduce reproductive interference and ensure reproductive success, sympatric species have a series of mechanism to minimize reproductive assurance.This study selected two sympatric distribution and pollinator sharing of Primula species such as Primula secundiflora and P. sikkimensis. Through pollinators fidelity survey, heterospecific pollen deposition tracing and the proportion ascertain, flower character matching analysis, we wanted to make sure that whether there was heterospecific pollen deposition and factors which influence heterospecific pollen deposition between two Prinula. This study also focused on the interspecific crossing examination to investigate the interspecific isolation and the level of heterospecific interference. Finally, we used different proportion of conspecific-hererospecific pollen deposition on a same stigma and conspecific-hererospecific pollen deposition at different time on a same stigma to study the influence of reproductive fitness of different pattern of heterospecific pollen deposition. The results are as follows:(1)There were heterospecific pollen deposition between P. secundiflora and P. sikkimensis, but the amount of heterospecific pollen is less. The heterospecific pollen proportion on the long style and short style of P. secundiflora is 8.94% and 2.07%; the heterospecific pollen proportion on the long style and short style of P. sikkimensis is 5.04% and 6.42%. There was no significant difference between two species and different morph of the same species.(2)The one foraging bout fidelity of shared pollinator bumblebee was 96.55%, which is relatively high.(3)The flower characters analysis of the same morph between P. secundiflora and P. sikkimensis showed that corolla diameter, calyx length, corolla tube width and stamens high are all significant difference between two species.(4)There was low seed set between interspecific hybridization, but there was no significant difference between two species and different morph of the same species.(5) Different patterns of heterospecific pollen deposition have different influence to P. secundiflora and P. sikkimensis. The proportion of heterospecific pollen deposition had a negatively correlated with reproductive fitness. Conspecific-heterospecific pollen deposited at different time all significantly reduced the reproductive fitness of P. secundiflora and P. sikkimensis, but there was no significant different of which deposit first.hn conclusion, our study showed that there was reproductive interference between sympatric P. secundiflora and P. sikkimensis by pollinator sharing. Pollinator fidelity and the difference between flower traits may create a contribution to reduce reproductive interference between P. secundiflora and P.sikkimensis. Heterospecific pollen deposition will reduce reproductive fitness of P. secundiflora and P. sikkimensis, and different pattern of deposition has a different influence.