Studies On Reproduction And Its Behavioral Ecology In 2 Species Of Viviparous Plants

The reproductive way, its behavior and adaptation to special ecological environment of two species of viviparous plantlets, i.e. Polygonum viviparum L. and Saxifraga cernua L., were studied between the elevations of 2160 m and 3800 m in the Urumqi River drainage basin. The main results are as follows:1,In respect of reproductive way, both species can reproduce in sexual and asexual way, but the asexual way is the main one.2,In respect of sexual reproduction, the success rate of sexual reproduction for both species is quite low. Female abortion happens during the period of macrospore meiosis and its further development for the species of Polygonum viviparum L. while male abortion happens in the course of microspore meiosis and the further development. So, sexual reproduction results in only quite a low number of seeds with quite a low rate of germination. As to the species of Saxifraga cernua L., male development is normal, while female development is abnormal basically, thus no seeds were collected.3,In respect of asexual propagation, both of the two species can produce viviparous plantlets., and the viviparous plantlets of both species are formed for the differentiation of floral primodium, but the position if viviparous plantlets is different. For the species of Polygonum viviparum L., the viviparous plantlets are formed in the inflorences, while in Saxifraga cernua L are in the leaf axils. On the results of observation for morphology and anatomy, vascular bundles of viviparous plantlet are connected with that of their parent. When the viviparous plantlet abscises, there are 1-3 leaflets on it. What' more, plants of species of Saxifraga cernua L. can also propagate by way of forming ramets.4,The plants show great morphological plasticity in different elevation and different micro-habitat of the same elevation. From lower to higher elevation, the capability for plant to produce ramet increases, the height of ramet decreases, the number of viviparous plantlets produced by genet increases, and the leaf number produced by the viviparous plantlets increased.5,In respect of Behavioral Ecology, both species can reproduce by way of forming viviparous plantlets. And it is a conversation from heterotrophy to semi- heterotrophy for the process of viviparous plantlets' formation and morphochoresis. Before the formation of leaves, the nutrition for the development of viviparous plantlet is supplied by its parent, which is a kind of typical foraging behavior. But as to parents, it is a kind of parental breeding behavior and altruism. When talking about heredity and fitness, such a kind of altruism is a sort of egoism too. The traits showed when the viviparous plantlets abscise and disperse that the dispersing behavior for the viviparous plantlets is adaptable to the special environment.