Study On Reproductive Ecology And Photosynthesis Characteristic Of Two Ecotype Vetiveria Zizanioides

Vetiver grass (Vetiveria zizanioides (L.) Nash)is a kind of unique gramineous plant with deep root. It has strong adaptability, broad ecologyscope and strong resistance .It is thought that it is the most ideal grass in conserving the water soil and restoring the soil fertility atin home and abroadc.This test taked two different ecotype vetiver grass (Sunshine and Wild) as the research object, compared the characteristic of sexual reproduction and, clonal reproduction under different density, the nutrition reproduction scale and the seed productive potential was measured, investigated the artificial vetiver grass group to be born the survival tendency, as well as the tiller number seasonal variation, and analysed two different ecotype photosynthesis characteristic in seedling stage, analysed population various characters under the different density.Through the biomass analysis, calculated the two ecotype reproduction allocation. The reproduction adaption strategy of two ecotype Vetiver grass was analysed comprehensively.There were significant differences in plant height and increasing velocity of the two cultivars between the two ecotype in seedling stage. The growth velocity of Wild was faster than that of Sunshine. The average ramet numbers and total ramet numbers had significant differences at seedling stage . The rapid periods of Wild and Sunshine were in late June and mid-July respectivelyThrough relevance analysis of tiller amount under different density ,it's discovered that total tiller number was related exponential function form to the density .Relevance has achieved the extremely remarkable level. The nutrition reproduction characteristic of two ecotype Vetiver grass population was different,although used the same the reproduction strategy which seizes the same space and the nutrition reproduces, but the time occupied and plant density cause two ecotype vetiver grass populations different in forming the population size through the nutrition reproduction. The Sunshine Vetiver grass 's reproduction assignment, Fructification Rate, the longth of ear, the weight of a thousand grain and the weight of a thousand seeds were higher than Wild.Through the measure of photosynthesis parameter, it was discovered that their light saturation points were close nearly in the seedling stage, but the light compensation point of Wild was clearly lower than that of Sunshine.The net Photosynthesis rate (Pn) and apparent quantum yield (AQY) of Sunshine were lower than those of Wild. Thus, the utilization of Solar Energy of Wild was higher than that of Sunshine. The CO₂ saturation point of Wild was lower than that of Sunshine and its compensation point was higher.