【作者】 高伟；

【导师】 刘奕清；

【作者基本信息】 长江大学 ， 园艺学， 2023， 硕士

【摘要】 生姜（Zingiber officinale Roscoe.）是药食同源蔬菜和出口创汇农产品,产量高、市场需求大、经济效益好,为我国乡村振兴的特色高效产业。近年来,一些生姜主产区由于种植年限增加,土壤盐渍化严重,引起生姜产量品质下降明显,阻碍了生姜产业的健康发展。硅（Silicon,Si）参与了植物的生长发育和逆境胁迫的响应过程,对促进植物生长和抵抗逆境具有积极作用。但目前关于生姜耐盐性的研究较少,其耐盐性评价的指标和方法缺少参考,Si在生姜中的耐盐机制尚不清楚。因此本研究对5个生姜主栽品种（山东大姜、凤头姜、竹根姜、贵州黄姜、罗平小黄姜）的耐盐性进行了鉴定评价,以发掘抗性优异种质、筛选耐盐指标;在此基础上,进一步探究SiNPs对生姜盐胁迫的缓解效应。研究结果如下:1.生姜耐盐鉴定方法与评价指标筛选。选取5个生姜品种,测定盐胁迫下生姜幼苗的生长形态特征和生理生化指标。结果表明:在盐胁迫条件下,各品种生姜幼苗的叶片出现黄化,株高、茎粗和叶片数的增加量、根系活力以及水势和渗透势降低,而丙二醛（MDA）和H₂O₂含量增加,抗氧化酶（超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）和苯丙氨酸解氨酶（PAL））活性也发生改变。主成分分析、隶属函数分析和综合评价的结果显示,5个生姜品种的耐盐性排序为:山东大姜>贵州黄姜>凤头姜>罗平小黄姜>竹根姜。相关性分析结果显示,根系活力与综合评价值D值呈极显著正相关,株高、茎粗和叶片数的增加量与D值呈显著正相关,植株的根系活力以及株高、茎粗和叶片数的增加量可作为生姜耐盐品种筛选鉴定的主要参考指标。2.外源Si缓解生姜盐胁迫的生理生化机制。先使用100 mg·L^-1 SiNPs溶液喷施生姜幼苗叶片,5 d后再进行盐胁迫处理,测定盐胁迫下生姜幼苗的生长形态、光合特性、细胞膜脂过氧化、抗氧化酶活性以及离子含量等指标。结果表明:在盐胁迫条件下,SiNPs处理的生姜幼苗的叶片发黄症状得到缓解,其总根长、根系表面积和根尖数显著增加;叶绿素a（Chl a）、叶绿素b（Chl b）和叶绿素a+b（Chl a+b）含量,最大光化学效率（F_v/F_m）、实际光量子效率（ΦPSII）和光化学淬灭系数（q P）,净光合速率（P_n）和蒸腾速率（T_r）,SOD、POD和CAT活性以及根、茎和叶片中的K⁺含量均显著提高;而非光学淬灭系数（NPQ）,MDA和H₂O₂含量以及根、根茎、茎和叶片中的Na⁺含量均显著降低。本研究结果表明,5个生姜品种耐盐性排序为:山东大姜>贵州黄姜>凤头姜>罗平小黄姜>竹根姜,根系活力以及株高、茎粗和叶片数的增加量可作为生姜耐盐品种筛选的主要参考指标。外源SiNPs处理通过促进植株根系生长、增加光合色素含量、增强PSⅡ反应中心的光化学活性、提高光合作用效率、调节抗氧化酶活性、降低细胞膜脂过氧化程度、减少Na⁺的积累以及促进K⁺的运输与再分配,从而缓解盐胁迫对生姜幼苗造成的不利影响。更多还原

【Abstract】 Ginger（Zingiber officinale Roscoe.）is a medicinal and edible vegetable and export agricultural products with high output,large market demand and good economic benefits,which is a special and efficient industry for the revitalization of rural areas in our country.In recent years,due to the increase of planting years and serious soil salinization in some main ginger producing areas,the yield and quality of ginger decreased obviously,which hindered the healthy development of ginger industry.Si（Silicon）is involved in the growth and stress response in plant,and plays a positive role in promoting plant growth and resistance to stress.However,there are few studies on the salt tolerance of ginger,the indexes and methods for evaluating the salt tolerance of ginger are lack of reference,and the salt tolerance mechanism of Si in ginger is not clear now.So this study identified and evaluated the salt tolerance of five main ginger cultivars（Shandongdajiang,Fengtoujiang,Zhugenjiang,Guizhouhuangjiang and Luopingxiaohuangjiang）,in order to explore excellent resistance germplasm and select salt tolerance indicators;on this basis,to further explore the mitigation effect of SiNPs on ginger salt stress.The results of the study are as follows:1.Identification methods and evaluation indexes of salt tolerance of ginger.Five ginger cultivars were selected to determine the growth morphological characteristics and physiological and biochemical indexes of ginger seedlings under salt stress.The results showed that under salt stress,the leaves of ginger seedlings were yellowed,the increase of plant height,stem diameter and leaf number,root vitality,water potential and osmotic potential decreased,while the contents of malondialdehyde（MDA）and H₂O₂ increased,and the activities of antioxidant enzymes（superoxide dismutase（SOD）,peroxidase（POD）,catalase（CAT）and phenylalaninammo-nialyase（PAL））also changed.The results of principal component analysis,membership function analysis and comprehensive evaluation showed that the order of salt tolerance of five ginger cultivars was Shandongdajiang>Guizhouhuangjiang>Fengtoujiang>Luopingxiaohuangjiang>Zhugenjiang.The results of correlation analysis showed that there was a very significant positive correlation between root vitality and comprehensive evaluation value D value,and a significant positive correlation between the increase of plant height,stem diameter and leaf number and D value.Root vitality and the increase of plant height,stem diameter and leaf number can be used as the main reference indexes for screening and identification of salt-tolerant ginger cultivars.2.Physiological and biochemical mechanisms of exogenous Si in alleviating salt stress in ginger.The leaves of ginger seedlings were sprayed with 100 mg·L^-1 SiNPs solution at first,and then treated with salt stress after 5 days.The growth morphology,photosynthetic characteristics,membrane lipid peroxidation,antioxidant enzyme activities and ion contents of ginger seedlings under salt stress were measured.The results showed that under salt stress,the leaf yellowing symptoms of ginger seedlings treated with SiNPs were alleviated,and total root length,root surface area and root tip number were significantly increased,chlorophyll a（Chl a）,chlorophyll b（Chl b）and chlorophyll a+b（Chl a+b）contents,maximum photochemical efficiency（F_v/F_m）,actual photoquantum efficiency（ΦPSII）and photochemical quenching coefficient（q P）,net photosynthetic rate（P_n）and transpiration rate（T_r）,SOD,POD and CAT activities,K⁺contents in roots,stems and leaves were significantly increased,while non-photochemical quenching coefficient（NPQ）,MDA and H₂O₂ contents,Na⁺contents in roots,rhizomes,stems and leaves were significantly decreased.The results showed that the order of salt tolerance of 5 ginger cultivars was Shandongdajiang>Guizhouhuangjiang>Fengtoujiang>Luopingxiaohuangjiang>Zhugenjiang.Root vitality and the increase of plant height,stem diameter and leaf number can be used as the main reference indexes for the selection of salt-tolerant ginger cultivars.Exogenous SiNPs treatment alleviated the adverse effects of salt stress on ginger seedlings by promoting root growth,increasing photosynthetic pigment contents,enhancing photochemical activity of PSⅡreaction center,improving photosynthetic efficiency,regulating antioxidant enzyme activities,reducing cell membrane lipid peroxidation,reducing Na⁺accumulation and promoting K⁺transport and redistribution.更多还原