锰胁迫对大叶胡枝子种子萌发和幼苗生理生化特征的影响  

Effects of manganese stress on seed germination and seedling physiological and biochemical characteristics of Lespedeza davidii

作　　者：胡佳瑶 王悟敏 匡雪韶 刘文胜[1] HU Jiayao;WANG Wumin;KUANG Xueshao;LIU Wensheng(School of Life Sciences and Technology,Central-South University of Forestry&Technology,Changsha 410004,China)

机构地区：[1]中南林业科技大学生命科学与技术学院,湖南长沙410004

出　　处：《安徽大学学报（自然科学版）》2022年第6期84-92,共9页Journal of Anhui University(Natural Science Edition)

基　　金：国家自然科学基金资助项目(42177018);湖南省自然科学基金资助项目(2021JJ31147);湖南省教育厅项目(20C1917)。

摘　　要：大叶胡枝子(Lespedeza davidii)为一种豆科灌木,生物量大,抗逆性强,能生物固氮.为揭示该植物对锰胁迫的适应性及其机制,以大叶胡枝子为对象,研究不同锰浓度(5,5000,15000μmol·L^(-1))对种子萌发及3个幼苗生长时期(7,15,30 d)生理生化特征的影响.结果表明,随着锰浓度的升高,大叶胡枝子种子发芽率无显著变化,均为98%左右;种子发芽势、发芽指数和活力指数则均降低,幼苗干重和根冠比均先升后降;随着锰浓度的升高,大叶胡枝子幼苗叶绿素a、叶绿素b含量均下降;在处理7 d时SOD,POD,CAT活性均上升,在处理30 d时SOD活性上升,POD活性下降,CAT活性先升后降;可溶性糖、可溶性蛋白和游离脯氨酸含量则增加,且游离脯氨酸含量随锰胁迫时间的延长先升后降;MDA含量增加,随着时间延长逐渐升高.以上结果显示大叶胡枝子具有较强的锰耐受性,可通过调节抗氧化酶活性来缓解锰胁迫的毒害作用.Lespedeza davidii is a leguminous shrub with large biomass,strong stress resistance and biological nitrogen fixation.In order to reveal the adaptability and mechanism of the plant to manganese stress,the effects of different manganese concentrations(5,5000,15000μmol·L^(-1))on seed germination,and physiological and biochemical characteristics of three seedling growth stages(7,15,30 d)were studied.The results showed that with the increase of manganese concentration,there was no significant change in the germination rate of L.davidii seeds,which was about 98%;seed germination potential,germination index and vigor index decreased,while seedling dry weight and root shoot ratio increased first and then decreased;with the increase of manganese concentration,the contents of chlorophyll a and chlorophyll b decreased;at 7 days,the activities of SOD,POD and CAT increased,at 30 days,the activity of SOD increased,the activity of POD decreased,and the activity of CAT increased first and then decreased;the contents of soluble sugar,soluble protein and free proline increased,and the content of free proline increased first and then decreased with the time of manganese stress;the content of MDA increased and gradually increased with time.The above results showed that L.davidii had strong manganese tolerance,and the toxicity of manganese tress could be alleviated by regulating the activity of antioxidant enzymes.

关 键 词：锰胁迫 大叶胡枝子 种子萌发 生理指标 幼苗生长 

分 类 号：Q945.78[生物学—植物学]