摘要
黄腐酸(FA)可参与植物耐旱性的调控,但关于其对干旱胁迫下黄瓜光合作用的调控机制尚不清楚。本研究以‘津优35’黄瓜为试材,采用聚乙二醇(PEG-6000)模拟干旱,通过喷施不同浓度(0、100、300、500、700、900 mg·L^(-1))FA,研究其缓解黄瓜干旱胁迫的浓度效应及其对光合关键酶活性、叶绿体超微结构、叶绿素荧光参数、水分利用效率及产量和品质的影响。结果表明:室内试验中,与对照(0 mg·L^(-1))相比,不同浓度FA处理均显著提高了干旱胁迫下黄瓜幼苗的叶片相对含水量和叶面积,降低旱害指数、丙二醛含量和电解质渗漏率,随着FA浓度的增加其缓解效应呈现先升高后下降的趋势,且以700 mg·L^(-1) FA的作用效果最好。FA显著增加干旱胁迫下黄瓜幼苗的叶绿素含量、Rubisco和Rubisco活化酶(RCA)活性及基因表达、净光合速率(P_(n))、最大光化学效率和实际光化学效率、单位面积吸收光能、捕获光能、电子传递的量子产额和PSⅠ活性,降低K点的上升,维持叶绿体超微结构。温室控水试验表明,FA可显著增加干旱胁迫下温室黄瓜的水分利用效率,促进干物质量的积累,增加果实中Vc、可溶性糖、可溶性蛋白和游离氨基酸含量,降低单宁含量。综上,施用FA可在干旱条件下提高温室黄瓜产量,改善果实品质。
Fulvic acid(FA)participates in the regulation of drought stress tolerance in plants,but the underlying mechanisms remain unclear.We carried out an experiment with cucumber cultivar‘Jinyou 35’as the test material and the polyethylene glycol(PEG-6000)being used to simulate drought stress.The concentration effect of FA on drought alleviation of cucumber as well as the effect of FA on photosynthetic enzymes activities,chloroplast ultrastructure,fluorescence parameters,water use efficiency,yield and quality of cucumber plants were studied through spraying FA with different concentrations(0,100,300,500,700 and 900 mg·L^(-1)).The results showed that FA with different concentrations significantly promoted the relative water content and leaf area and decreased drought injure index as well as the electrolyte leakage and malondialdehyde(MDA)content,compared with the control(0 mg·L^(-1))under drought stress.The mitigative effect of FA increased first and then decreased with the increases of FA concentration,with 700 mg·L^(-1) FA showing the best effect.FA significantly enhanced the chlorophyll content,Rubiasco and Rubisco activase(RCA)activities and gene expression,net photosynthesis(P_(n)),maximal photochemical efficiency of PSⅡin darkness,actual photochemical efficiency,absorbed light energy per unit area,captured light energy per unit area,quantum yield of electron transport and PSⅠactivity,decreased the increase of K point and maintained chloroplast ultrastructure.The experiment in solar-greenhouse showed that FA obviously increased water use efficiency,promoted dry matter accumulation as well as the contents of Vc,soluble sugar,soluble protein and free amino acid,and decreased tannin content.Our results suggested that FA could improve the yield and quality of cucumber in solar greenhouse under drought stress.
作者
刘彩娟
吕春雨
艾希珍
毕焕改
LIU Cai-juan;LYU Chun-yu;AI Xi-zhen;BI Huan-gai(College of Horticulture Science and Engineering,Shandong Agricultural University/State Key Laboratory of Crop Biology/Key Laboratory of Horticultural Crop Biology and Germplasm Innovation in Huang Huai Region of Ministry of Agriculture/Collaborative Innovation Center of Shandong Province with High Quality and Efficient Production of Fruit and Vegetable,Tai'an 271018,Shandong,China)
出处
《应用生态学报》
CAS
CSCD
北大核心
2022年第5期1300-1310,共11页
Chinese Journal of Applied Ecology
基金
山东省重点研发计划项目(2019GNC106047)
山东省现代农业产业技术体系建设专项(SDAIT-05-10)资助。
关键词
干旱
黄腐酸
光合系统
产量
品质
黄瓜
drought
fulvic acid
photosynthetic system
yield
quality
cucumber