不同磷效率马褂木种源对磷胁迫的生理反应

低磷胁迫条件下,植物将以一系列形态、生理、生化和遗传机制主动适应胁迫环境,包括根系对生长环境中难溶性磷的活化,有效吸收、运转、分配及再利用等.植物通过改变对养分的需求以维持自身代谢和改变根系形态、生理机能来增强自身活化和吸收养分的强度1].具有较高的磷素吸收能力是植物耐低磷胁迫的基础2],研究低磷胁迫条件下植物的生理生化特性对揭示耐低磷机理具有重要意义.以往在农作物方面有过一些研究3～6],但在林木方面研究不多.本试验以不同磷效率的马褂木(Liriodendron chinense (Hemsl.)Sarg.)6个种源为材料,试图研究低磷营养胁迫下马褂木种源在膜脂过氧化、可溶性蛋白含量、叶绿素含量及酸性磷酸酶活性等方面的差异及与磷效率的关系,为优良耐低磷马褂木种源的选育提供理论依据.

Physiological Response of Liriodendron chinense Provenances with Different Phosphorus Efficiency under Low Phosphorus Stress

Soil culture experiments at two phosphorus levels were conducted to study the physiological responses(including chlorophyll content,MDA and soluble protein content,and APase activity in roots and leaves) of six Liriodendron chinese provenances with different phosphorus efficiency(PE). The result showed that low phosphorus stress would decelerate seedling growth and leaf development,lessen chlorophyll content and MDA content in leaves,and promote APase activity in root.There existed marked differences in physiological response among provenances with various PE under low phosphorus stress.It was found that the provenances with high PE possessed more and larger leaves,higher chlorophyll and soluble protein content than those provenances with low PE.Change of MDA content in leaves of provenances with high PE was small at two phosphorus levels,which meant the provenances with high PE were more resistive to environment stress.