The Study On Adaptability Under The Temperature And Water Stress For Eragrostis

Ornamental grass (Eragrostis spectabilis (Linn.) Beauv.), a kind of annual bunch grass, long flowering period, strong resistance, extensive management, is widely used in gardens, slope stabilization, indoor greening. In recent years, with the greenhouse effect increasing, global average temperature has gradually increased, so that damage health on plant. the heat tolerance of ornamental grass has become one of the new topics. Eragrostis spectabilis (Linn.) Beauv. (love grass) and Eragrostis pilosa (L.) Beauv. Use as the test materials under PEG osmotic stress Eragrostis seed germination characteristics, high temperature and drought stress and the absolutely high temperature stress in the leaves of the total chlorophyll content, MDA content, the free proline content and the soluble proteins content and other physiological and biochemical indexes, and the experiment of comparing the preliminary study Eragrostis drought and heat resistance physiological mechanism.The results are as follows:1.Under the PEG osmotic stress, Eragrostis seeds are obviously influenced in activity indicators:the germination drought resistance index (GDRI), relative vigor index, relative germination rate and germination energy and relative radical length, relative length and relative embryo radicle/embryo ratio.Love grass and the local Eragrostis have similar drought resistance.2. Using the artificial climate chamber to simulate high temperature and drought stress on two Eragrostis,this experiment determinate the external morphology and the physiological and biochemical indicators (total chlorophyll, MDA, SPC, SOD, POD, etc.) to compare the resistance of the two Eragrostis. The results showed that:Under the high temperature and drought stress, with the sharp decline in soil moisture, two Eragrostis showed obvious signs of persecution. The various physiological and biochemical indicators are significant changed, the total chlorophyll content of the local Eragrostis is higher than that of love grass; whereas the MDA, love grass is significantly higher than the local Eragrostis, the maximum of love grass is 73.78umol/g, and the local Eragrostis only 66.65 umol/g; these two indicators above suggested the local Eragrostis resistance in dry and heat is higher than love grass. And in these indicators of the soluble sugar content, free proline, soluble protein, SOD activity and CAT activity,the two Eragrostis don't have difference,So the two Eragrostis have similar resistance.The POD activity of the local Eragrostis is significantly higher than that of love grass CK group,but in the WS group, there is not any difference between the two Eragrostis,indicating that the POD activity of love grass is significantly lower than the local area Eragrostis.3. Eragrostis's resistance about the physiological and biochemical indicators of screening are:the moisture content in soil, total chlorophyll content, MDA, proline, SOD, POD.4. In the absolute heat stress experiments, the total chlorophyll content of love grass and the local Eragrostis were:1.10mg/g,0.87 mg/g; in the MDA and proline content the Local Eragrostis is significantly higher than love grass; through the three indicators above, the heat resistance of love grass is stronger than that of local Eragrostis. In soluble protein and photosynthetic rate, the heat resistance of Eragrostis are similar. But the transpiration rate, love grass is lower than the local.5. When in the natural stress, the two Eragrostis demonstrated similar resistance.6. In smmary, the resistance between the two Eragrostis are similar in drought resistance and heat resistance, but there are some differences:the heat resistance of love grass is stronger than that of local Eragrostis, but the drought resistance of love grass is weaker than than the local species. love grass, as the introduction of species, can be successful introducted and adapt to the environment in Chongqing, and will play an important role in landscape ecology in the Chongqing area.