摘要
【目的】本文系统研究了不同浓度NaCl胁迫及外源脱落酸(ABA)对NaCl胁迫下甘薯幼苗生根及一些生理生化特性的影响,探讨了外源ABA对盐胁迫下甘薯幼苗的缓解效应,为增强盐碱地甘薯耐盐性、提高产量提供理论依据。【方法】以甘薯种植品种徐薯25为实验材料,在装有石英砂的具孔塑料盆中放入培养室自然光照/昼夜温度[(26±1)/(17±1)℃]中培养,并进行不同浓度NaCl处理以及对NaCl 300 mmol/L胁迫甘薯幼苗叶片喷施ABA溶液,连续处理7 d后,测定生根数,使用CIRAS-1型便携式光合仪测定光合作用指标、植物效率分析仪测定叶绿素荧光参数、采用比色法测定丙二醛、脯氨酸、可溶性糖含量和超氧化物歧化酶活性、用原子吸收分光光度计测定Na+、K+、Ca2+含量,利用SPSS13.0和Excel软件对数据进行处理分析。【结果】低浓度NaCl胁迫(50 mmol/L)对甘薯幼苗影响较小;随着盐度的增加,甘薯生根不断减少,相对电导率、丙二醛(MDA)、脯氨酸和可溶性糖含量持续增加,甘薯叶片超氧化物歧化酶(SOD)活性呈先增加后降低趋势;叶片净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、光系统Ⅱ(PSⅡ)最大光化学效率(Fv/Fm)、捕获的激子将电子传递到电子传递链中超过QA的其他电子受体的概率(Ψ0)、用于电子传递的量子产额(ΦE0)逐渐降低,放氧复合体活性(Vk)和用于热耗散的量子比率(ΦD0)不断增加;叶片中Na+含量增加,K+、Ca2+和K+/Na+水平降低。高浓度(300 mmol/L)NaCl胁迫下,甘薯幼苗的正常生理代谢受到显著抑制。适当增加外源ABA浓度,能够显著缓解NaCl胁迫造成的伤害作用,以ABA浓度为70μmol/L的缓解效果最好。【结论】外源ABA可显著促进盐胁迫下甘薯幼苗生根,维持细胞膜的稳定性,降低膜脂过氧化程度,调节植物细胞的渗透和离子动态平衡,使甘薯幼苗叶片维持较高的Fv/Fm、Ψ0、ΦE0和较低的Vk、ΦD0,缓解PSⅡ光抑�
【Objectives】The physiological effects of exogenous abscisic acid（ ABA） on the tolerance of sweet potato seedlings variety Xushu 25 to NaCl stress were analyzed to provide a theoretical basis for enhancing the salt tolerance and improving the yield of sweet potato.【Methods】The sweet potato seedlings of variety Xushu 25 were treated with different concentrations of NaCl,and the leaves of sweet potato seedlings exposed to NaCl with different concentrations in culture mediums were continuously sprayed by the solutions containing different concentrations ofABA for 7 d. Root amounts of seedlings were determined,and photosynthesis index was measured using a portable photosynthetic apparatus, and chlorophyll fluorescence was determined by a plant efficiency analyzer. The concentrations of Na＋,K＋,Ca2 ＋in leaves were determined by atomic absorption spectrophotometer,and the levels of MDA, proline, soluble sugar and the activity of superoxide dismutase in leaves were respectively determined by colorimetric method. 【Results 】 The sweet potato seedlings were lightly affected by NaCl of 50 mmol / L. With the increase of salinity,the root growth rate was decreased,while the relative conductivity and the contents of MDA,proline and soluble sugars were increased,and the activity of superoxide dismutase showed an increase trend,and then gradually decreased. The Pn,Tr,Gs,Fv / Fm,Ψ0and ΦE0values in the leaves were decreased,but those for Vk and ΦD0increased. Except Na＋,the contents of K＋,Ca2 ＋and the ratio of K＋/ Na＋were decreased. The growth and metabolism were significantly affected by higher concentration of NaCl.Application of exogenous ABA significantly abates the poison ous effect of NaCl on sweet potato seedlings,and the best effect was obtained in ABA concentration of 70 μmol / L. 【Conclusions】Exogenous ABA could significantly promote the root growth of sweet potato seedlings,reduce the degree of membrane lipid oxidation,and keep higher values of Fv / Fm,Ψ0and ΦE0,but lower values of
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2016年第1期201-208,共8页
Journal of Plant Nutrition and Fertilizers
基金
国家甘薯产业技术体系甘薯营养与栽培生理岗位(CARS-11-B-14)
国家自然科学基金项目(31270314)
青岛农业大学人才基金项目(630743)
山东省泰山学者岗位项目资助
