Seed dispersal mechanism of Erythronium japonicum in Northeast China

Seed dispersal is recognized as a very important stage in the life history of plant sexual reproduction. Seed dispersal directly determines whether plant seeds can reach the favorable germination sites and ensure the successful germination of seeds subsequently which is the first stage of plant seedling establishment. The final dispersal location of seeds with diplochory usually requires the joint decision of two stages including primary seed dispersal and secondary seed dispersal. The seed dispersal of Erythronium japonicum by ants was investigated in three different habitats. The effect of seed maturity on seed fate and the effects of elaiosome removal and water immersion on seed dispersal in the wild were studied. The results showed that eight species of ants were involved in E. japonicum seed dispersal in the three habitats. The seed handling efficiency and the number of seeds transported by ants were affected by the composition of ant community and the size of ant population. There was a strong correlation between the seed dispersal distance and the body length of ants. Small ants may have expanded their foraging range through fierce struggle. The immature E. japonicum seeds will also be handling by ants, indicating that the seed elaiosome mature prior to seeds. We found elaiosome plays an important role in the dispersal of E. japonicum seeds, and it can also be used as a “handle point” for smaller ants. The components of elaiosome are not easily soluble in water, which can avoid the loss of the attraction of E. japonicum seeds to ants due to the rain during the seed dispersal process. •Elaiosome plays an important role in the dispersal of seeds, it can also be used as a "handle point" for smaller ants.•Elaiosome has more energy, which increased the attraction of seeds to ants at the lower seed aggregation degree.•High density of seeds are more likely to attract ants, it is easy to cause a larger proportion of seeds can't be dispersed.