摘要
【目的】研究不同基因型核桃实生幼苗对盐胁迫的生长及生理响应状况,综合评价其耐盐能力,为盐碱地区耐盐品种的筛选提供参考。【方法】以新新2号(JX2)、温185(JW185)、扎343(JZ343)和辽宁1号(JL1)共4种基因型种子的当年生实生苗为材料,以不同浓度NaCl溶液(0、50、100、200和300 mmol·L^(-1))进行胁迫处理,观测幼苗生长状况,测定处理不同天数(6、12、18和24天)的光合参数、膜透性、渗透调节物质、酶活性和内源激素含量等相关生理指标,对4种基因型的耐盐能力进行综合评价。【结果】1)盐胁迫条件下,4种基因型幼苗的生长受到不同程度的影响,各基因型的叶片均表现出了不同程度的枯黄、卷曲和脱落等盐害症状,苗高增量、地径增量及植株干质量等生长指标随NaCl浓度的增加呈下降趋势,其中,JX2生长状况相对较好,受抑制程度较轻。2)随盐浓度的增加和胁迫时间的延长,各基因型的叶绿素含量和光合参数总体呈下降趋势,JX2较对照的降幅较小,表现较好。3)随盐浓度的增加和胁迫时间的延长,相对电导率(REC)和丙二醛(MDA)含量总体呈上升趋势,其中,JX2的REC值和MDA含量较低,较对照增幅较小,JZ343则相反。4)随盐浓度的增加和胁迫时间的延长,脯氨酸(Pro)含量总体呈上升趋势,可溶性糖(SS)和酶活性总体表现为先增加后减少,其中,JX2积累的Pro和SS较多,并且JX2的酶活性较高。5)在内源激素方面,促进脱落酸(ABA)生成的同时抑制了生长素(IAA)等的合成。【结论】盐胁迫显著影响各基因型幼苗的生长和光合作用,使其叶片细胞光合活性降低,植株生长减缓,幼苗能够通过增加渗透调节物质含量、提高酶活性、调节自身激素平衡等机制来应对盐胁迫。通过综合评价可知,4种基因型耐盐能力的大小顺序为:JX2>JW185>JL1>JZ343。
【Objective】In this study,the growth and physiological responses of walnut seedlings with different genotypes to salt stress were studied,and their salt tolerance was comprehensively evaluated,which would provide reference for screening salttolerant varieties in saline-alkali areas.【Method】Seedlings derived from 4 genotypes of Juglans regia‘Xinxin2’(JX2),J.regia‘Wen185’(JW185),J.regia‘Zha343’(JZ343),and J.regia‘Liaoning1’(JL1)were used as test materials,and subjected to five NaCl concentration gradients(0,50,100,200 and 300 mmol·L^(-1)).The photosynthetic parameters,membrane permeability,osmotic adjustment substances,enzyme activity and endogenous hormone content of the four genotypes were measured for different days(6,12,18 and 24 days),and the salt tolerance of the four genotypes was comprehensively evaluated.【Result】1)Under salt stress,the growth of seedlings of four genotypes was affected to different degrees,and the leaves of all genotypes showed different degrees of salt damage symptoms,such as yellowing,curling and shedding.The growth indexes such as seedling height increment,ground diameter increment and plant dry weight showed a downward trend with the increase of NaCl concentration.Among the 4 genotypes,JX2 grew relatively better and was less inhibited.2)With the increase of salt concentration and the prolongation of stress time,the chlorophyll content and photosynthetic parameters of each genotype generally showed a downward trend,and JX2 showed a smaller decline than the control,and performed better.3)With the increase of salt concentration and the prolongation of stress time,relative electrical conductivity(REC)and malondialdehyde(MDA)content showed an overall upward trend.Among the 4 genotypes,JX2 had lower the REC value and MDA content,with a smaller increase compared to the control,while JZ343 was the opposite.4)With the increase of salt concentration and the prolongation of stress time,proline(Pro)content generally showed an upward trend,soluble sugars(SS)and enzyme activities showed an overall increase followed by a decrease.Among the 4 genotypes,JX2 accumulated more Pro and SS,and had higher enzyme activity.5)In terms of endogenous hormones,salt stress promoted the production of abscisic acid(ABA)and inhibited the synthesis of indole-3-acetic acid(IAA).【Conclusion】Salt stress significantly affects the growth and photosynthesis of walnut seedlings,by reducing the photosynthesis activity of leaf cells.Seedlings can cope with salt stress by increasing the content of osmotic adjustment substances,improving enzyme activity and regulating their endogenous hormone balance.The comprehensive evaluation of salt tolerance indicates the following order of magnitude of salt tolerance among the four genotypes:JX2>JW185>JL1>JZ343.
作者
姬新颖
唐佳莉
李敖
郑旭
王红霞
张俊佩
Ji Xinying;Tang Jiali;Li Ao;Zheng Xu;Wang Hongxia;Zhang Junpei(State Key Laboratory of Tree Genetics and Breeding Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration Research Institute of Forestry,Chinese Academy of Forestry Beijing 100091;Mountainous Areas Research Institute,Hebei Agricultural University Technology Innovation Center for Agriculture in Mountainous Areas of Hebei Province National Engineering Research Center for Agriculture in Northern Mountainous Areas Baoding 071000)
出处
《林业科学》
EI
CAS
CSCD
北大核心
2024年第2期65-77,共13页
Scientia Silvae Sinicae
基金
国家重点研发计划项目(2022YFD2200402)。
关键词
核桃
盐胁迫
生长指标
生理响应
主成分分析
walnut
salt stress
growth index
physiological response
principal component analysis