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

The reproduction and its behavioral ecology of RhaJiola caccinea. and Poa bu/bosa subsp.vivqara were studied by observating the characters of growth, development and reproduction of the natural population or the artifical population. The main results are as follows; 1. Rhodiola coccinea(llnyle) A.Bor. (1 )This species is perennial dioecy and has two ways of reproduction which include sexual reproduction and vegetative propagation. Its seed-set rate is low The efficiency of vegetative propagation is high. (2)The flower is monosexed in the period of flower buds differentiation in pistillate plant. The flower is bisexed in the period of flower buds differentiation in staminiferous plant. At early stage, the development of the bisexed flowers is normal. But the female gametophyte has degenerated before the stage of 4ucleus embryo sac. It is at the intermediate stage from bisexual to monosexual flower and belongs to the sexual system of sub-monosexual dioecy. (3)Based on the theory of sexual conflict of interest ,the aim of the separation between female and male is to make good use of resources and complete its reproductive function on condition of limitation of resource allocation. The character of reproduction is an adaptive strategies of reproductive behavior. 2. Poa bulbosa subsp.vivqwra(KoeI.) Arcang. (l)This species has two ways of reproduction which include sexual reproduction and vegetative propagation, but vegetative propagation is the major way of reproduction and it includes two methods. One is to form ramets in rhizoma, the other is to form viviparous plantlets in spikelet. (2)Fruits can not be found in field observation By embryological observation, the flower bud differentiation of this species and early stage of the development of pistil and stamina is normal, but there is a serious abortion at late stage of the development of pistil and stamina. Microspore abortion occurs mostly from meiosis stage to early period of microspore formation. Macrospore abortion occurs mostly at meiosis stage. (3)The top axis of spikelet does not stop growing ailer 1-3 flowers differentiation, but has a reversal change directly from reproductive to vegetative growth and form viviparous plantlet. (4)The living mode of viviparous plantlet is heterotrophy and parasitic at the stage from differentiation to the first leaf stretching out. The genet supplies all nutrition to viviparous plantlet. But the successive stage of semi- heterotropby and parasitic is from the first leaf stretching out to drop or from the first leaf stretching out to fall with stem and taking-root, and the nutrition of viviparous plantlet is supplied by genet and the rest by itself through photosynthesis. It is a foraging behavior of viviparous plantlet and a parental breeding behavior of genet. The behavior is benefit to population. (5)This species shows morphological plasticity in response to varying habitat. (6)The formation of viviparous plantlet can not be simply considered a reversion. The mode of viviparous reproduction has evolutionary significance from the point of its adaptability to environment.