铝对橡胶树生长的影响及其与死皮病发生的关联研究

Aluminium is one of the most vital constraints restricting plant growth and development in tropical acid soil. Meanwhile, tapping panel dryness (TPD) is the most intractable issue for latex loss in worldwide rubber plantations since its first found a hundred years ago. To date, the exact cause and mechanism about TPD is still unclear, consequently, no efficient method to prevent and control TPD is identified. It is found that there is a significant positive relationship between TPD incidence and soil exchangeable aluminium. However no any further study was.conducted. For the first time, this project is set to examine the translocation of aluminium in Hevea and effects of aluminium on the rubber tree growth performances, latex yield and phloem anatomy both from the field investigation and simulation tests. Thus, the hypothesis that aluminium toxicity resulted from soil acidification is an incentive of phloem TPD could be verified. In addition, the mechanism of aluminum detoxifying for the rubber tree could be examined. The project aims to resolve the key problem encountered in rubber tree cultivation and.tropical soil protection. It is the first research to scrutinize the impact of aluminum on plant phloem development and rubber tree TPD. It is likely that a measure to prevent the prevalence of TPD by controlling soil aluminum content will be suggested.

酸性土壤上的铝毒是制约热带地区农林业发展的重要环境问题。而橡胶树割面干涸病（死皮病）是严重影响巴西橡胶树产量的百年难题。研究表明，橡胶树死皮病发生率与土壤可交换性铝含量间存在一定关联，但在橡胶树死皮病发生机制尚不清楚、也没有有效防控手段的情况下，尚未见铝对橡胶树生长的影响及其与死皮病关联的报道。围绕“胶园土壤酸化所致的铝毒可能是导致橡胶树死皮病发生的诱因”这一新假说，本项目基于前期初步结果，利用室内和大田模拟试验，首次系统开展铝对橡胶树根生长和水分传导的影响，铝在橡胶树体内的转移累积特性，铝累积对橡胶树胶乳代谢、乳管发育及生长的影响，橡胶树解除铝毒的机制及铝与死皮病发生的关联研究。开创性地从铝毒角度探讨了橡胶树死皮病发生与防治问题。项目针对热区胶园土壤酸化及死皮日趋严重的重大问题选题，成果对橡胶树死皮病防治这一百年难题的解决、植物铝毒机制的扩展和热区环境保护均具有重要的理论意义。

酸性土壤上的铝毒是制约热带地区农林业发展的重要环境问题,与橡胶树死皮发生率间存在一定的关联。但对铝毒对橡胶生长发育的影响及其与橡胶树产量、死皮病之间的关联尚未见研究报道。围绕“胶园土壤酸化所致的铝毒可能是导致橡胶树死皮病发生的诱因”这一新假说，本项目利用室内和大田模拟试验，首次系统研究了铝对橡胶树根生长和水分传导的影响，铝在橡胶树体内的转移累积特性，铝累积对橡胶树胶乳代谢、乳管发育及生长的影响及橡胶树解除铝毒的机制。证明橡胶树对铝的耐受范围在100-200mM之间，是种非常耐铝的热带树种;低浓度的铝对橡胶树光合生理、胶乳产量和胶乳生理参数等无显著影响，但高浓度铝会使橡胶树根系累积铝，造成生长发育受阻、根系活力下降、根尖细胞程序性死亡，导水能力下降；根系吸收的铝可向地上部分运输，导致地上部分出现水分胁迫，活性氧累积，叶片含水量和光合能力下降，产胶能力下降；土壤铝毒虽然会影响橡胶树生产和产量，但并不是导致橡胶树死皮的直接原因；橡胶树主要是通过根系大量分泌有机酸尤其是草酸达到解铝目的的。从橡胶树中克隆得到铝诱导性苹果酸转运体和草酸转运体，有望为进一步研究橡胶树耐铝机制和筛选耐铝橡胶树品种提供依据。项目针对热区胶园土壤酸化及死皮日趋严重的重大问题选题，成果对橡胶树死皮病防治这一百年难题的解决、植物铝毒机制的扩展和热区环境保护均具有重要的理论意义。