摘要
以河南烟区主栽烟草(Nicotiana tabacum)品种‘豫烟10号’和‘豫烟12号’为供试材料,利用聚乙二醇(PEG)-6000渗透胁迫模拟轻度、中度和重度干旱胁迫环境,研究了烟草抗旱性生理指标对苗期不同程度水分亏缺的响应机制及其与烟株耐旱性的关系。结果表明:(1)相比于对照组,低浓度PEG胁迫能促进烟草幼苗叶片叶绿素(Chl)含量和抗氧化酶活性提高;叶片丙二醛(MDA)和过氧化氢(H_2O_2)含量随着干旱程度的加剧持续升高;重度水分胁迫时,幼苗叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)等保护酶活性以及Chl含量均显著下降。(2)应用隶属函数法对各项抗旱性生理指标进行综合评价,2个烟草品种苗期抗旱性强弱顺序为‘豫烟12号’>‘豫烟10号’,总体趋势表现为水分条件越差二者抗旱性差异越明显,‘豫烟12号’幼苗的各生理生化指标较‘豫烟10号’受干旱影响小,干旱胁迫下仍保持较强的抗氧化酶活性是‘豫烟12号’耐旱的主要生理原因,这是不同品种通过自身生理调节来适应外部环境变化的结果。(3)灰色关联分析表明,各参数与抗旱隶属函数值关联程度顺序依次为MDA>SOD>(Chl a/Chl b)>H_2O_2>CAT>POD>(Chl a+b),说明叶片内MDA含量、SOD活性和Chl a/Chl b可作为烟草品种苗期抗旱性鉴定的有效指标,而H_2O_2含量、CAT活性、POD活性和Chl a+b参数可作为抗旱性鉴定参考指标。
Drought is one of the numerous environmental factors which seriously affects the growth and development of plants,and it is becoming more severe in many regions of the world due to climate change.To examine physiological responses of tobacco seedling to polyethylene glycol（PEG） stress and provide theoretical basis for evaluating drought resistance and screening tobacco species,the physiological and biochemical indexes of two tobacco cultivars were investigated under the conditions of light drought（LD）,intermediate drought（ID） and severe drought（SD）.The results show that malondialdehyde（MDA） and hydrogen peroxide（H2O2） contents were significantly increased than those of the control,while activities of protective enzymes and chlorophyll contents were obviously increased and then significantly decreased under the ID or SD treatments.The enzyme activities in ‘Yuyan 10＇ increased more strongly than those in ‘Yuyan 12＇.Meanwhile,MDA content in ‘Yuyan 10＇ changed more obviously than that in ‘Yuyan 12＇,which may be related to the enhanced enzyme activity during droughts,more exactly,a strong negative correlativity between MDA content and enzyme activities was shown under water stress.Subordinate function of drought-resistance and its correlation with drought-resistance indexes of tobacco species were used for a quantitative evaluation of comprehensive drought-resistance.The capabilities of drought-resistance for two different tobacco species were in the order ‘Yuyan 12＇‘Yuyan 10＇.There was a significant tendency that drought-resistant varieties were more easily adapted to water stress environment than drought-susceptible varieties,and the slight variations of index only occurred in the drought-resistant varieties.The grey correlative degree of drought-resistance with other physiological indexes was in the rank of MDA content,SOD activity,H2O2 content,Chl a/Chl b,POD activity,CAT activity and Chl a＋b content.Therefore,the SOD activity,MDA content and Chl a/Chl b can be used as effective indicators for the identification of drought resistance,while H2O2 content,CAT activity,POD activity and Chl a＋b content can be used for reference indicators at seedling stage for tobacco species.
出处
《植物生理学报》
CAS
CSCD
北大核心
2016年第12期1861-1871,共11页
Plant Physiology Journal
基金
国家自然科学基金(31200393)
河南省烟草公司科技攻关项目(HYKJ 201210和HYKJ 201405)~~
关键词
烟草
干旱胁迫
生理响应
抗旱性
评价
tobacco
drought stress
physiological response
drought resistance
evaluation
