旋扭山绿豆（Desmodium intortum）营养器官的形态解剖特点与高固氮、耐阴和水土保持的关系

旋扭山绿豆（Ｄｅｓｍｏｄｉｕｍｉｎｔｏｒｔｕｍ）不仅是营养价值高的牧草，而且是耐阴、高固氮和适于水土保持的植物。本植物由主根、各级侧根和不定根组成庞大的根系．各种根都可长出根瘤。其根瘤形成时间较早．数量较多．８５％以上为有效根瘤．类菌体力棒形．茎半匍匐，分枝多，复盖面积大，节及节间都能产生不定根。其叶较薄．气孔较少．叶绿体较大．其内淀粉粒少．基粒片层较丰富，因而能耐阴、在２０％遮阴下生长最好。

THE RELATIONSHIP BETWEEN THE MORPHOLOGICAL AND ANATOMICAL CHARACTERS OF VEGETATIVE ORGANS OF DESMODIUM INTORTUM AND THE HIGH NITROGEN FIXATION, SHADE TOLERANCE AND CONSERVATION OF SOIL AND WATER

Desmodium intortum (Mill. ) Fawc. et Rendle is a pasture with abundant nutrition and a plant species which Possesses shade tolerance, high nitrogen fixation and is suitable to soil and water conservation. Its root nodules can form in the root system consisting of main root, lateral roots and adventitious roots. Root nodules form soon and in quantity.The effective rate of root nodule is more than 85%. Bacterioid in root nodules is in theshape of club. The somewhat stoloniform stem has many branches and hence will cover larger area. The adventitious root can easily be produced from node or internode. The character of its shade tolerance is related to its thin leaf, less stomata, bigger chloroplasts which contain less starch grains and abundant grana. It grows well in 20% shade condition.