干旱对马尾松茎叶水力特征及解剖特性的影响  

Effects of drought on hydraulic and anatomical characteristics of stem and leaf in Pinus massoniana

作　　者：邵畅畅 罗仙英 丁贵杰 段洪浪[1,2] 赵熙州 娄清 SHAO Changchang;LUO Xianying;DING Guijie;DUAN Honglang;ZHAO Xizhou;LOU Qing(Research Center for Forest Resources and Environment of Guizhou Province/Guizhou Key Laboratory of Plateau Mountain Tree Breeding,Guizhou University,Guiyang 550025,China;College of Forestry,Guizhou University,Guiyang 550025,China)

机构地区：[1]贵州大学贵州省森林资源与环境研究中心/贵州省高原山地林木培育重点实验室,贵阳550025 [2]贵州大学林学院,贵阳550025

出　　处：《植物生理学报》2022年第5期937-945,共9页Plant Physiology Journal

基　　金：国家“十三五”重点研发项目(2017YFD0600302);贵州省科技计划项目后补助计划项目(黔科合平台人才[2018]5261)。

摘　　要：本文通过研究不同干旱梯度下马尾松(Pinus massoniana)的水力特征及解剖特性,以期全面了解马尾松对干旱的适应机制。以17个月苗龄马尾松苗为材料,设置正常浇水(CK)、中度干旱(MD)和重度干旱(HD)3个水平(分别占田间持水量的75%~80%、35%~40%、25%~30%),分析了不同处理对马尾松水势、含水量、木质部栓塞程度(PLC)、管胞直径、木质部和韧皮部面积等的影响。结果显示:在不同干旱程度下,各项指标均有明显的变化。马尾松苗木茎和叶水势在不同干旱程度下变化不同,根对干旱最敏感。苗木会通过改变光合碳同化与蒸腾速率以及干物质量与耗水量的比例,提高水分利用效率。随着干旱程度的加重,木质部栓塞程度也加重,苗木针叶和茎的结构发生明显的变化。干旱胁迫下,苗木通过主动调整内部结构来增加水分运输效率和数量,从而更好地适应干旱;严重干旱下,内部结构变形,水分运输受阻,但叶片会维持较高的韧皮部面积来提供更高的碳运输效率,降低叶片的碳饥饿风险,防止苗木因在水分状况较差的情况下出现碳耗竭而快速死亡。This study intends to deepen understanding the adaptation mechanism of Pinus massoniana to drought by studying the hydraulic and anatomical characteristics.Potted seedlings of one year and five months old years P.massoniana were treated under conditions of well-watered(CK),moderate drought(MD)and severe drought(HD),representing 75%–80%,35%–40%and 25%–30%of field capacity,respectively.The effects of different treatments on water potential,water content,degree of xylem embolism(PLC),tracheid diameter,xylem area and phloem area of P.massoniana were analyzed.The results showed that under different degree of drought intensity,all traits had the big change.The water potential in stem and leaf had different changes at different degrees of drought,and the root was most sensitive to the drought.Seedlings could improve water use efficiency by changing the ratio of photosynthetic carbon assimilation and transpiration rate,dry matter accumulation to water consumption.With the increase of the drought degree,the PLC rose significantly,and structures changed a lot.Under the drought stress,seedlings can adjust internal structure to increase water transport efficiency and quantity to better adapt to drought,under severe drought,the internal structure is deformed and water transportation is blocked,but the seedlings will maintain a higher phloem area on the leaves to provide higher carbon transportation efficiency,reduce the risk of carbon starvation of the leaves and prevent the rapid mortality of seedlings due to carbon depletion in the case of poor water conditions.

关 键 词：马尾松 水分运输 解剖结构 木质部栓塞 

分 类 号：S791.248[农业科学—林木遗传育种]