| The area of the drought and desert in China is very vast.The problems of vegetation deteriorated,soil erosion and soil desertification are increasingly serious.The hilly Loess Plateau is one of the most serious region of soil erosion in China,although managed for several years,the soil erosion area still has 450.000km2 at the end of 2005,that is the total area' s 71%.In the "Three North" region of our country,especially north China and northwest regeion,the weather is dry,the land is poor,and the ecosystem problem is increasingly serious.Therefore to choice a tree that can look after the both sides of the ecosystem performance and economic performance is not only the key place of the forestry development,but also the important topic of the forestry research.Caragana as the agrestic bush of the "three north" region,has stronger ability to defend wind and sand.It can not only keep water and soil,beautify environment,but also provide high-quality feed.Therefore to study the drought tolerance in Caragana and select the breeds of the strong drought tolerance,will provide the ories basis and the technique support to the plant recovered and the choice of the plant category in the dry region of our country.Betaine is a nonpoisonous and very effective osmopretectant existed in many organisms.More research state:Betaine is the impotent osmopretectant.It can raise the ability of the cell osmoregulation,lower the injury towers the cell membrane and the protein structure coursed by the osmotic water lose.It has the impotent physiology function to adapt plant to the environment stress,enhance the tolerance of plants to every stress factor. Caragana has the strong ability to against the stress,but the study about the Betaine in Caragana didn't appear know.This article uses the method which in the open country sampling investiga-tion and the room analyzes unifies, investigated the Betaine synthesis state in each organs of the Caragana microphylla under the nature state,compared the Betaine level with other trees,and studied the effects of abscisic acid(ABA) and Water-stress on the betaine concentration in the leaves of Caraganamicrophylla.Results showed that:(1)Each organs of Caragana microphylla all contain Betaine,and the contents are not equal.The betaine contents in bud,branch,leaf,fruit and root of Caragana microphylla were 39μmolg-1FW,21μmolg-1FW, 30μmolg-1FW,31μmolg-1FW,37μmolg-1FW。From the results we could know that,The contents of bud and root are the most,fruit and leaves' are mid,and the branch' s is the least.(2)The betaine contents in buds of Caragana microphylla,Pear,Peach and Jujube were 39μmolg-1FW,40μmolg-1FW,38μmolg-1FW, 42μmolg-1FW。The leaves were 30μmolg-1FW,21μmolg-1FW,16μmolg-1FW,30μmolg-1FW。And the branches were 21μmolg-1FW,33μmolg-1FW,28μmolg-1FW,20μmolg-1FW。Through compared we could know that all buds of Caragana microphylla,Pear,Peach and Jujube under the nature state contain high level betaine;From the betaine level of leaves and branches to see,Caragana microphylla and Jujube are more near,Pear and Peach are near,and the results of leaves and branches are quite contrary.(3)The results that the changes of betaine level in leaves of Caraganamicrophylla under the water stress:PEG treatment and nature dry,showed that in the stress courses,there were not conspicuous increased of the betaine level in the Caragana microphylla leaves subjected to water stress.(4)There was not conspicuous effect of exogenous ABA on the betaine contents in the leaves of Caragana microphylla under the water stress, and there was not found the increase in betaine level of Caragana microphylla leaves subjected to water stress.
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