虎尾草不同器官矿质元素含量对碱化环境的响应  

Effects of alkali stress on the content of mineral elements in different organs of Chloris virgata

作　　者：项越 赵淑婷 吴昊 李政 张震宇 王欢[1] XIANG Yue;ZHAO Shuting;WU Hao;LI Zheng;ZHANG Zhenyu;WANG Huan(Faculty of Agronomy,Jilin Agricultural University,Changchun 130118,Jilin,China)

机构地区：[1]吉林农业大学农学院,吉林长春130118

出　　处：《草业科学》2022年第3期511-519,共9页Pratacultural Science

基　　金：国家自然科学基金青年科学基金“高碱化环境下羊草根分泌过程及其抗碱机理研究”(31802114);中国博士后科学基金第61批面上项目“碱地肤和羊草抗碱机制研究”(2017M610197)。

摘　　要：虎尾草(Chloris virgata)是天然抗碱盐生植物,为深入探究其抗碱生理机制,本研究选择盆栽营养液控制培养方法,使用150 mmol·L^(-1)碱性盐溶液(NaHCO_(3):Na_(2)CO_(3)=9:1)对虎尾草幼苗进行长达一个月的碱胁迫处理,研究碱胁迫对虎尾草叶片光合作用、不同器官(茎叶、穗和根)中不同矿质元素(Na、K、Ca、Mg、P、Fe)积累的影响,并计算不同矿质元素在不同器官间的分布。结果表明:长期碱化环境下,虎尾草叶片光合指标明显下降,同时降低虎尾草不同器官中K、Ca、P和Mg大量元素的含量。对虎尾草不同元素在不同器官间的积累分布百分率分析表明,碱胁迫后,Na、K、Ca、Mg、Fe各元素在茎叶中相对含量明显高于穗和根(P <0.05),而P元素碱胁迫后仍在穗中大量积累,虎尾草P元素在穗中积累49.80%,碱胁迫后为50.02%。虎尾草各元素在整株植物不同器官中占所有元素总含量贡献百分率具体分析表明,元素K大量分布在茎叶、穗和根中,其次是Ca、P元素,在碱化环境下,3个器官中均大量积累Na元素,尤其是茎叶中元素Na的相对含量由原来的0.707%升高至28.397%,胁迫后茎叶中元素Na含量是无胁迫对照的28.399倍,而虎尾草穗部仍维持较高的K含量,供给穗正常生长。综上所述,虎尾草在长期碱化环境下抽穗完成生活史,表现在对Na有较强的调节能力,在根和茎叶中积累大量的Na来保护幼嫩的穗,同时仍能维持正常的元素P含量,保证正常的生理代谢过程来抵抗碱化环境带来的伤害。Chloris virgata is a naturally occurring alkali-tolerant halophyte. To explore the physiological mechanism underlying the alkali tolerance of C. virgata, we used 150 mmol·L^(-1)alkaline salt solution( Na HCO_(3):Na_(2)CO_(3)= 9 : 1) to treat C. virgata seedlings for one month. After the alkali stress treatment, we detected different mineral elements(Na, K, Ca,Mg, P, and Fe) and calculated the distribution of each mineral element among different organs(shoots, spikes, and roots). We also observed changes in leaf photosynthesis. The results indicated that long-term alkali stress strongly inhibited leaf photosynthesis and reduced the contents of K, Ca, P, and Mg in different organs. Analysis of the distribution of each element among the three organs showed that the relative contents of Na, K, Ca, Mg, and Fe in shoots were significantly higher than those in spikes and roots under alkali stress(P < 0.05). However, P still largely accumulated in the spike under alkali stress,and the contribution of P to the total element in the spike reached 49.80% under the control condition and 50.02% under the alkali stress condition. Analysis of the contribution percentage of each element to the total showed that K content was much higher than that of other elements in all organs, followed by Ca and P. Under alkali stress conditions, Na was extensively accumulated in all three organs, especially in shoots, where Na accumulation was enhanced from 0.707% to 28.397% by alkali stress. The shoot Na content of the alkali stress treatment was 28.399-fold that of the control treatment. However,under alkaline stress conditions, the spikes of C. virgata maintained a high K content, which supports the normal growth of the spike. In conclusion, C. virgata can complete its life cycle under long-term alkali stress conditions because of its strong ability to regulate Na. C. virgata protects young spikes under long-term alkali stress by enhancing the accumulation of Na in roots and shoots and lowering the accumulation of Na in the spike. C. virga

关 键 词：虎尾草 碱胁迫 不同器官 光合指标 元素积累 元素占比 元素贡献率 

分 类 号：S544.9[农业科学—作物学]