The Investigation Of Native Ground-cover Plant And Research Of Ecological And Biological Characteristics On Pennisetum Centrasiaticum Tzvel

With the increase in green area, water consumption is also growing, the shortage of water resources is more and more serious, especially for the cities locate on the North in China, it has become an important limiting factor in sustainable development of socio-economic and ecological environment. Therefore, a scientific concept should be established. It has became a hot topic to use the native ground-cover which has high adaptability and drought-tolerant capacity.The study has been conducted an investigation and evaluation on the main ground-cover plant in Lanzhou City, and a part of ecological and biological characteristics of Pennisetum centrasiaticum Tzvel were conducted, the results was follows.(1) Ground-cover plants have very large value for application and promotion, accordding to investagation, we recommend that the excellent and potential 25 kinds of ground-cover plants should be developed and used in lanzhou.(2) In the different conditions, the germination rate of the Pennisetum centrasiaticum Tzvel was not significantly different, but the germination index, the activity index, the radicle length and the fresh weight of Pennisetum centrasiaticum Tzvel is different under different temperatures, the Pennisetum centrasiaticum Tzvel has the best germination at 25°C.(3) In the entire reproductive growth period of Pennisetum centrasiaticum Tzvel, the allocation rate of the biomass in Pennisetum centrasiaticum for its rhizome and vegetative growth was much higher , and that for sexual growth was less. The ratio of the biomass of leaf, vagina and shoot was large during reproductive growth.(4) The coefficient of variation of sexual reproduction traits of Pennisetum centrasiaticum was as follows: sseed weight of single spike> number of seed setting> seed setting percentage >weight of spike > number of floret > length of spike > thousand seed weight. Length of spike, number of floret, number of seed setting and weight of spike had a significantly correlated with Seed weight of single spike. Number of seed setting was more important, it should be as an important indicator of sexual reproduction. (5) Daily variation of net photosynthetic rate in Pennisetum centrasiaticum presented a single peak curve, no midday depression. The peak value of the net photosynthetic rate was occurred at 12 :00, and photosynthetic rate was a significant positive correlation with PAR. Daily variation of transpiration rate in Pennisetum centrasiaticum was also a single peak curve. The peak value of the transpiration rate was occurred at 14 :00, and transpiration rate was a significant positive correlation with PAR and temperature. The changes of water use efficiency of Pennisetum centrasiaticum is double curve. Seasonal variation of transpiration rate in Pennisetum centrasiaticum had the cignificant law, it reached the maximum in July , and was positively correlated with the PAR and emperature. The water use efficiency in May and September was higher than that in others, was significantly negative correlation with temperature.