摘要
【目的】探究黑果腺肋花楸在自然土壤干旱条件下的光合及其生理生化特性。【方法】以3年生的黑果腺肋花楸盆栽苗木为试材,通过持续干旱处理,观测苗木叶片的水分参数、光合及叶绿素荧光参数、保护酶活性和渗透调节物质含量等指标的动态变化规律,并对这些生理参数进行相关性和主成分分析。【结果】在自然干旱的过程中,叶片相对含水量(RWC)显著降低,而水分饱和亏(WSD)显著增加;光合色素包括Chl a、Car和总叶绿素含量随着土壤含水量的降低呈先上升后下降的趋势。在初期阶段,当土壤含水量由田间持水量80%~75%(CK)下降至40%~35%(T3)时,黑果腺肋花楸苗叶片的净光合速率(P_(n))、气孔导度(G_(s))和蒸腾速率(Tr)呈逐渐降低的趋势;而水分利用效率(WUE)则显著提高;PSⅡ最大光化学效率(F_(v)/F_(m))与对照组无显著差异。随着土壤干旱程度加剧,P_(n)、G_(s)、T_(r)和F_(v)/F_(m)下降幅度越大,而C_(i)上升显著。通过观察叶片P_(n)、G_(s)、C_(i)和F_(v)/F_(m)的变化趋势和相关性分析,在干旱前、中期影响黑果腺肋花楸光合特性的主要因素是气孔限制,在后期则出现非气孔限制。随着干旱的加剧,叶片的质膜受损,电解质外渗率显著增加;丙二醛和H2O2含量以及超氧化物歧化酶、过氧化物酶和过氧化氢酶活性呈先上升后下降的趋势;同时,渗透调节物质含量也逐渐增加。综合分析各指标之间的相关性发现,不仅各个参数内部存在显著相关性,而且水分、光合参数、保护酶活性和渗透调节物质指标之间也存在重要关联。【结论】综合考虑测定指标的主成分分析和评价结果,黑果腺肋花楸在面临持续干旱胁迫时,会迅速降低气孔导度以减少水分散失并提高水分利用效率,会通过提高部分光合色素含量维持光合结构PSⅡ的正常功能以应对干旱环境。同时,在干旱胁迫下,它能通过调节自身保护酶活性及增加渗透调节物质含量来缓解干旱胁迫造成的伤害,表现出较强的适应干旱逆境的能力。
【Objective】To investigate photosynthetic,physiological and biochemical characteristics of Aronia melanocarpa seedlings under natural soil drought.【Method】A study was conducted using 3-year-old potted seedlings as experimental materials.The continuous drought treatment was applied through natural drying method.The dynamic changes in leaf water parameters,photosynthesis and chlorophyll fluorescence parameters,protective enzyme activity,and osmoregulation substance content under continuous drought conditions were monitored.Correlation analysis and principal component analysis were conducted on these physiological parameters.【Result】During the natural drought process,a significant decrease in the relative water content(RWC)of leaves was observed,accompanied by a notable increase in water saturation deficit(WSD).As soil moisture decreased,an initial increase in the content of photosynthetic pigments,including Chl a,Car,and total chlorophyll was observed,followed by a subsequent decline.Soil moisture content decreased from 80%-75%(CK)to 40%-35%(T3)of field capacity,net photosynthetic rate(P_(n)),stomatal conductance(G_(s)),and transpiration rate(T_(r))of A.melanocarpa seedlings gradually decreased;however,water use efficiency(WUE)increased significantly.It was worth noting that there was no significant difference observed in PSⅡmaximum photochemical efficiency(F_(v)/F_(m))compared to the control group.As soil drought intensified,the decline P_(n),G_(s),Tr,and F_(v)/F_(m) became more pronounced,while C_(i) exhibits a noticeable increased.By observing the trends and correlations among leaf P_(n),G_(s),C_(i),and F_(v)/F_(m).It could be inferred that stomatal limitation was the main factor affecting the photosynthetic characteristics of A.melanocarpa during early to mid-drought period.However,non-stomatal limitations became prominent in the later stages.As drought conditions intensify,the integrity of leaf membranes was compromised,resulting in a significant increase in electrolyte leakage rate;Initially,the content of MDA and H_(2)O_(2) as well as activities of superoxide dismutase(SOD),peroxidase(POD),and catalase(CAT)exhibited an increase followed by a subsequent decrease;Simultaneously,there was a gradual accumulation of osmoregulation substances.Through comprehensive analysis of the relationships among various indicators,it was observed that significant correlations exist not only within individual parameters but also between water availability,photosynthetic parameters,protective enzyme activity,and osmotic adjustment substances.【Conclusion】Based on the results of principal component analysis and evaluation of measurement indicators,These findings suggest that A.melanocarpa responds to drought stress by rapidly reducing stomatal conductance to minimize water loss and enhance water use efficiency.Additionally,It maintains normal functioning of PSⅡin photosynthetic structure by increasing certain pigment contents to adapt to drought conditions.Furthermore,it demonstrates a strong ability to cope with drought stress by regulating protective enzyme activity and increasing osmoregulatory substance content as a means of mitigating damage caused by drought stress.
作者
艾力江·麦麦提
祖丽皮耶·托合提麦麦提
蒋艳
秦倩
亚里坤·努尔
徐敏
Ailijiang Maimaiti;Zulipiye Tuohetimaimaiti;JIANG Yan;QIN Qian;Yalikun Nuer;XU Min(College of Life Sciences,Xinjiang Agricultural University,Urumqi 830052,Xinjiang,China;Xinjiang Key Laboratory for Ecological Adaptation and Evolution of Extreme Environment Biology,Xinjiang Agricultural University,Urumqi 830052,Xinjiang,China;College of Horticulture,Xinjiang Agricultural University,Urumqi 830052,Xinjiang,China;College of Forestry and Landscape Architecture,Xinjiang Agricultural University,Urumqi 830052,Xinjiang,China)
出处
《经济林研究》
北大核心
2024年第2期131-144,共14页
Non-wood Forest Research
基金
新疆维吾尔自治区自然科学基金项目(2021D01A89)
新疆维吾尔自治区人力资源和社会保障厅高层次人才引进工程项目(2017-2020)
新疆农业大学大学生创新训练计划项目(dxscx20191216)。
关键词
黑果腺肋花楸
自然干旱
光合作用
保护酶
渗透调节
Aronia melanocarpa
natural soil drought
photosynthesis
protective enzyme
osmoregulation
