外施褪黑素对干旱胁迫的长序榆光合与碳氮磷积累及其化学计量比的影响  

Effects of Melatonin on Photosynthesis, Accumulation of C, N, P and Their Stoichiometry in Ulmus elongata under Drought Stress

作　　者：洪震 洪琮浩 徐艳 闫道良[3] Hong Zhen;Hong Conghao;Xu Yan;Yan Daoliang(Scientific Research and Management Center of East China Pharmaceutical Botanical Garden,Lishui 323000,P.R.China;Beijing Forestry University;State Key Laboratory of Subtropical Silviculture,Zhejiang A&F)

机构地区：[1]华东药用植物园科研管理中心,丽水323000 [2]北京林业大学 [3]省部共建亚热带森林培育国家重点实验室(浙江农林大学)

出　　处：《东北林业大学学报》2022年第9期29-34,共6页Journal of Northeast Forestry University

基　　金：浙江省丽水市科技计划项目(2016ZDYF08)。

摘　　要：以1年生幼苗为试验材料,研究了在中度干旱(质量分数为0.10%)和重度干旱(质量分数20%)的聚乙二醇6000模拟的干旱胁迫下,外施浓度为100μmol/L的褪黑素对长序榆幼苗生长、叶片光合性能、碳水化合物质量分数和碳、氮、磷质量分数及其化学计量比的影响。结果表明:干旱胁迫下长序榆的叶片表现不同程度的黄化现象,根、叶生物量积累受到抑制,且重度干旱对幼苗的生长抑制较为明显。外施褪黑素能缓解干旱对叶片的损伤及植株的生物量积累。在正常生长条件下,喷施褪黑素显著提高了叶片的净光合速率,对干旱胁迫下的净光合速率、水分利用效率、气孔导度和蒸腾速率虽有一定的促进作用,但并不显著。施加褪黑素显著降低了中度干旱胁迫下胞间二氧化碳摩尔分数和气孔限制值。干旱胁迫显著降低了根、叶中淀粉质量分数和叶中的可溶性多糖质量分数。外施褪黑素后显著降低了干旱胁迫下长序榆根中可溶性总糖质量分数,显著增加叶中的总淀粉质量分数,叶中的非结构性碳水化合物质量分数则表现明显下降。施加褪黑素提高了干旱胁迫下叶中的N和P质量分数,明显降低根中的N和P质量分数,同时,根中的w(C)∶w(N)、w(C)∶w(P)有不同程度的提高。说明外源褪黑素通过调节C、N、P的重新分配增强长序榆幼苗的抗旱性。外施一定浓度的褪黑素能有效缓解干旱胁迫对长序榆生长的抑制作用,提高叶片N、P积累和根中N、P的利用效率,从而在元素水平方面增强对干旱胁迫的适应。We used one-year-old seedlings of Ulmus elongata as the experimental material and analyzed the effect of spraying 100 μM melatonin on U. elongata seedlings’ growth, leaf photosynthetic capacities, the content of carbohydrate, carbon(C), nitrogen(N), phosphorus(P), and their stoichiometry ratio under no drought(0%), moderate drought(10%) and severe drought(20%)(simulated by the different mass fractions of polyethylene glycol(PEG), represented as percentages). The results showed that the leaves of U. elongata presented different degrees of yellowing under drought stress, the biomass accumulation of roots and leaves was inhibited, and the growth of seedlings was significantly inhibited by severe drought. Spraying melatonin could alleviate the damage of drought to leaves and the biomass accumulation of plants. Under normal conditions(no drought), the application of spraying melatonin significantly increased the speed of leaves’ net photosynthesis. However, the effect of spraying melatonin on the speed of leaves’ net photosynthesis, water use efficiency, stomatal conductance, and transpiration rate under drought stress is not statistically significant. The application of spraying melatonin significantly reduced intercellular carbon dioxide concentration and stomatal limit under moderate drought stress. Drought stress significantly reduced root and leaf starch concentration, and leaf soluble polysaccharide concentration. Spraying melatonin under drought stress significantly decreased the concentration of soluble sugar in roots, increased the concentration of starch in leaves, and decreased the concentration of non-structural carbohydrate in leaves. The application of spraying melatonin increased the concentration of nitrogen(N) and phosphorus(P) in leaves and significantly decreased the concentration of N and P in roots under drought stress. Meanwhile, the ratio of w(C)∶w(N) and w(C)∶w(P) in roots increased in varying degrees. The results showed that spraying exogenous melatonin enhanced the drought resistan

关 键 词：干旱胁迫 褪黑素 长序榆 光合作用 碳氮磷 计量比 

分 类 号：S718.43[农业科学—林学]