Amphicarpy and dispersal mechanism of Viola tuberifera endemic to QinghaiTibetan Plateau

Viola tuberifera endemic to QinghaiTibetan Plateau was used to study the amphicarpy and morphological characteristics, spatial location and dispersal mechanism. The results showed that it has three types of fruits, i.e., CH fruit, aerial CL fruit and subterranean CL fruit. The these three fruits were different in quantity, spatial location and mature period. V. tuberifera has sexual and asexual types of diaspores, i.e., CH seeds, aerial CL seeds, subterranean CL seeds and cloning organ bulbs. Though the number of CH seeds was relatively small, the outcross accounted for the major part of CH seeds for necessary variation. The number of aerial CL seeds was the largest and this could ensure the primary approach for longdistance spread. Two subterranean diaspores could not move so the shortdistance spread could keep the continuation of species. The amphicarpy and the diversity of dispersal mechanisms of V. tuberifera was the special reproduction mode as the result of adaptation to the environment of QinghaiTibetan Plateau. The amphicarpy was firstly found in Violaceae in this study.