低磷胁迫对不同种源马尾松幼苗的影响

对不同种源马尾松在低磷胁迫下形态和生理生化方面的变化进行研究的结果表明:各种源幼苗的苗高、地径的净增量变化趋势一致,P3>P2>P4>P1。随磷浓度的降低根冠比增加,极低磷处理条件下各种源根冠比均最大。低磷逆境下,马尾松针叶MDA含量、保护酶活性(POD、SOD、CAT),以及游离脯氨酸含量均增加,这些指标的变化是马尾松适应低磷胁迫的主要生理影响机制之一。磷浓度为5～10 mg/L时,3个种源幼苗生长最佳。其中,贵州孟关种源较湖南汝城和广西古蓬种源更耐低磷胁迫。

Effects of Low - phosphorus Stress on Pinus massoniana at Different Provenances

Making sand culture experiment by artificial control of phosphorus concentration method in the greenhouse to study morphological and physiological and biochemical changes of Pinus massoniana seedlings from different provenances in low phosphorus stress. The results show that the trends of net increment in seedling height and ground diameter of seedlings from different provenances were consistent： P3 〉 P2 〉 P4 〉 P1. Root - shoot ratio increased with phosphorus concentration decreased, root - shoot ratio of seedlings from different provenances was the maximum under the condition of extremely low phosphate treatment. Under low phosphorus stress, all of the MDA content in needles of Pinus massoniana, protective enzyme activities and free proline content increased, these aspects formed a dynamic equilibrium which was one of the main physiological effects mechanisms for Pinus massoniana to adapt to low phosphorus stress. Three provenance seedlings were the best growth when phosphorus concentration was 5.0 - 10. 0 mg/L, in which, provenance form Guizhou Mengguan was more tolerant to low phosphorus stress than provenance from Hunan Rucheng and Guangxi Gupeng.