Fundamental Research of Development of Environmental Stress Tolerant Tree Species for Reforestation of Degraded Land in Tropics

本研究旨在筛选热带退化土地对环境胁迫的耐受性树种，并阐明其耐受性机制。(1)研究了几种热带豆科树木在不同pH条件下的生长响应，发现不同树种对pH的适应范围不同。(2)研究了热带豆科树木有机酸排泄作为一种耐铝机制。铝胁迫诱导仙丹根分泌柠檬酸盐。(3)研究了沼泽乔木种子萌发过程中的胁迫响应。千层木适应退化沼泽的胁迫条件。(4)研究了核桃千层的发酵酶活性及其耐涝机理。根系中ADH活性受洪水胁迫的影响。(5)建立了龙脑树组织培养体系。

The present study was aimed at screening tolerant tree species for environmental stress in degraded land in tropics and clarifying the tolerant mechanism.(1) Growth response of some tropical leguminous trees was studied by solution culture controlled in various pH.The adaptable range for pH was varied among the species.(2) As an aluminium-tolerance mechanism, excretion of organic acids in tropical leguminous trees was studied. Excretion of citrate was induced by aluminium stress from the roots of Praserianthes falcataria.(3) Stress response in seed germination of swamp trees was studied. Melaleuca cajuputi was adapted to stress condition of degraded swamp.(4) As a flooding-tolerance mechanism, activity of fermentative enzyme in Melaleuca cajuputi was studied. ADH activity in the roots was induced by flooding stress.(5) The tissue culture system of dipterocarp trees was established.