【作者】 高飞翔；

【导师】 张自和；

【作者基本信息】 兰州大学 ， 草业科学， 2008， 硕士

【摘要】 随着绿地面积的不断增加,其用水量也不断扩大,导致水资源紧缺日益突出,特别是我国北方城市,水资源短缺已成为社会经济与生态环境可持续发展的重要限制因子。因此,确立科学的绿化观,合理利用当地适应性强、耐旱的本土地被植物资源,实现可持续绿化和人与自然的和谐发展,日益被人们所关注。本研究对兰州市主要优良乡本地被植物进行了调查和评价,并对本土地被植物白草的部分生物生态学特性作了重点研究,得出如下结论。(1)本土地被植物具有非常大的应用和推广价值,经过初步调查与筛选,我们推荐对兰州优良的、极具开发利用潜力的25种本土地被植物进行更深入的研究。(2)在实验设置的几个不同的条件下,白草(Pennisetum centrasiaticum Tzvel)的发芽率没有显著的不同,但是不同温度条件下白草的发芽指数、活力指数、胚根长度、胚芽长度以及萌发苗的鲜重都有所不同,在25℃条件下,白草发芽效果最好。(3)在白草的整个生殖生长时期,白草的生物量分配一直为营养枝＞根茎＞生殖枝,在各个物候期,不管是营养枝还是生殖枝,各构件的生物量分配基本都表现为叶、茎和叶鞘所占比例较大。(4)白草有性繁殖性状的变异系数的大小排序如下:单穗粒重＞结实数＞结实率＞穗重＞小花数＞穗长＞千粒重。对各个性状进行了相关分析,穗长、小花数、结实数、穗重均与单穗粒重有显著正相关,并且单穗结实数比结实率和其它性状更为重要,应当作为评价白草有性繁殖的重要指标。(5)白草的光合日变化为单峰曲线,中午最高,光合速率与光照强度呈极显著的正相关。白草蒸腾作用日变化也为单峰曲线,其最高值出现在午后14时,白草蒸腾日变化与温度、叶温呈显著正相关,与光强呈极显著正相关。白草的水分利用效率的日变化为双峰曲线,其最高值出现在上午10时,次高值出现在下午18时。白草蒸腾速率季节变化为抛物线,7月份达到最大值,并且与光照、温度呈显著正相关。水分利用效率为5月和9月明显高于其它月份,与气温和叶温呈显著的负相关。更多还原

【Abstract】 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.更多还原