【作者】 崔聪聪；

【导师】 郭世荣；

【作者基本信息】 南京农业大学 ， 蔬菜学， 2008， 硕士

【摘要】 嫁接是一种重要的农艺措施,主要用于防止土传病害的发生,广泛应用于西瓜、甜瓜、黄瓜、番茄和茄子等作物上,在园艺生产中发挥着重要作用。近年来,我国设施栽培面积迅速增加,但设施土壤次生盐渍化日益严重,已成为限制设施蔬菜生产可持续发展的主要因子。西瓜（Citrullus vulgaris Schrad）是我国主要的蔬菜作物之一,在设施和露地中均广泛种植,但近年来由于土壤盐渍化的影响,产量和品质逐年下降,因此进行嫁接提高西瓜耐盐性研究对指导西瓜生产和提高我国园艺设施的利用效率具有重要的理论和实践意义。本研究针对设施栽培土壤盐渍化日益严重的现状,以搜集到的西瓜砧木为试材,筛选适宜设施栽培的耐盐西瓜砧木,并对其耐盐机理进行探讨。主要研究结果如下:1.选用耐盐性不同的‘丰源先锋’、‘丰源铁甲’、‘全能铁甲’、‘京欣砧一号’、‘佳人水瓜’、‘超丰抗生王’、‘FR-将军’7种砧木为材料,研究了90 mmol·L^-1NaCl处理下各砧木幼苗植株的生物积累量、株高、茎粗等生长指标及光合特性。结果表明,NaCl处理使各砧木品种的生物积累量均明显降低,株高、茎粗的生长受到抑制;叶片净光合速率（Pn）、气孔导度（Gs）等光合参数下降。不同砧木品种的耐盐性差异较大,其中‘超丰抗生王’受抑制程度较小,耐性较强。2.采用营养液栽培,以‘丰源先锋’、‘超丰抗生王’、‘FR-将军’砧木为材料,对100 mmol·L^-1INaCl处理下不同砧木幼苗生长、膜脂过氧化程度、渗透调节物质含量、叶片光合特性以及不同器官K⁺、Na⁺、Cl^-、Ca²⁺含量变化进行了研究。结果表明,盐胁迫下各砧木品种生长均受到不同程度抑制,株高、茎粗、根体积等均低于对照,地上部、地下部生物量显著下降,‘超丰抗生王’各项指标下降幅度较小,植株受盐胁迫伤害较轻;盐胁迫下植株幼苗细胞膜结构遭到破坏,质膜透性增加,相对电导率大幅度提高,细胞膜脂过氧化程度明显加剧,丙二醛（MDA）含量显著增加,盐胁迫对植株造成伤害。盐胁迫条件下‘超丰抗生王’膜脂过氧化程度较轻,受胁迫程度较小;NaCl胁迫后砧木Pn、Gs下降,光合色素含量上升,光合作用受到明显抑制,‘超丰抗生王’各项指标变化幅度小于‘丰源先锋’和‘FR-将军’,耐盐性较强。NaCl胁迫下砧木植株体内K⁺、Ca²⁺含量下降,Na⁺和Cl^-含量升高,其中‘超丰抗生王’叶片及根系中Na⁺和Cl^-含量升高幅度小于‘丰源先锋’和‘FR-将军’,对K⁺、Ca²⁺的吸收强于‘丰源先锋’和‘FR-将军’,有利于盐胁迫下维持正常的生理活动和较高的光合活性,耐盐性较强。以上结果证明,不同砧木品种对盐胁迫反应不同,盐胁迫下‘超丰抗生王’砧木幼苗生长受抑制程度较小,渗透物质调节能力及光合作用强于‘丰源先锋’和‘FR-将军’,植株受伤害较轻,对盐胁迫的耐性较强。3.以‘超丰抗生王’为砧木,‘秀丽’为接穗进行嫁接,研究了100mmol·L^-1NaCl胁迫对西瓜嫁接苗和自根苗幼苗植株生长、光合参数、叶绿素荧光参数（PSⅡ光化学效率）以及不同器官K⁺、Na⁺、Ca²⁺和Cl^-含量变化的影响。结果表明:1) NaCl胁迫显著降低了嫁接苗及自根苗植株生长量、Pn、Gs、胞问CO₂浓度（Ci）、PSⅡ实际光化学效率（ΦPSⅡ）和光化学淬灭系数（qP）,而对PSⅡ最大光化学效率（Fv/Fm）无显著影响;同等盐胁迫条件下,嫁接苗受抑制程度明显小于自根苗。2) NaCl胁迫处理9d,西瓜嫁接苗和自根苗叶片Na⁺、Cl^-含量显著增加,但嫁接苗增加幅度小于自根苗,这对减轻过量Na⁺、Cl^-对叶片光合作用以及其他生理生化代谢活动的抑制具有重要意义;西瓜嫁接苗和自根苗叶片与根系K⁺、Ca²⁺均降低,但嫁接苗植株各器官K⁺、Ca²⁺含量高于自根苗,表明嫁接换根增强了K⁺和Ca²⁺的选择性吸收和运输,在一定程度上缓解了过量Na⁺造成的毒害,提高了耐盐性。更多还原

【Abstract】 Grafting in is an important agricultural technique,Grafting in is mainly used to limit the effects of soil diseases.It has been widely used in such crops as watermelon, melon,cucumber,tomato and eggplant,el al..It plays an important role in the production of horticulture.In recent years,with the cultivation expanded greatly in the greenhouse,the secondary salinization of the soil is becoming worse and has become a leading factor of limiting the sustainable development of vegetable production. Watermelon（Citrullus vulgaris Schrad） is an important vegetable and is widely planted in open field and greenhouse.But because of the effects of soil salinization, Yield and Quality decrease year by year.Therefore,the research of salt tolerance in cucumber is of theoretic and practical significance to direct the production of cucumber and improve the use efficiency of greenhouse.Contraposing the actuality of salt accumulation of soil of protected cultivation becoming more serious in greenhouse,collected watermelon stocks were used as materials in this study to select salt-tolerant stocks suit for greenhouse culture,and its mechanism was studied.The main results as following:1.In the present study,’Feng yuan xian feng’,’Feng yuan tie jia’,’Quan neng tie jia’,’Jing xin zhen NO.1’,’Jia ren shui gua’,’Chao feng kang sheng wang’ and ’FR’-jiang jun’ were chosen as experimental materials.With water culture,we investigated that effects of 90 mmol·L^-1NaCl on the growth,plant height,and stem diameters of stock seedlings.The results showed that:biomass of all shock varieties decreased,plant height and stem diameters were inhibited,net photosynthesis, stomatal conductance of leaves descended,photosynthesis decreased.And the tolerance of salt stress was different in different varieties,’Chao feng kang sheng wang’ was the degree of inhibition is smaller,and the tolerance was higher than that of the other varieties.2.The study was conducted in nutrient solution to investigate the effects of NaCl stress on growth,membrane lipid peroxide level,osmoregulation substances, photosynthetic characteristics and of watermelon stocks,including pumpkin cultivar （’Feng yuan xian feng’） and calabash cultivar（Chao feng kang sheng wang and FR-Jiang jun）.The results showed that the growth of every stock cultivar were restrained NaCl stress.Under NaCl stress plant height,stem thickness,total volume of roots and so on,were lower than those of control.The dry and fresh weight of seedling decreased markedly.All indexes of ’Chao feng kang sheng wang’ decreased less than other varieties.Under salt stress,membrane structure was damaged, membrane permeability was increased,relative conductivity was increased significantly,superoxidation of membrane lipid was evidently picked up,and MDA content was increased significantly,so plants were damaged in salt stress.Under NaCI exposure,superoxidation of membrane lipid and injury of ’Chao feng kang sheng wang’ was less than other varieties.The net photosynthetic rate and stomatal conductance also decreased,but the content of photosynthetic pigment increased. Photosynthesis was restrained significantly under NaCl stress.Different stocks were different to salt tolerance.Changes of all kinds of indexes in ’Chao feng kang sheng wang’ were less than those in ’Feng yuan xian feng’ and ’Jiang jun’.Under salt stress, K⁺,Ca²⁺ content decreased,Na⁺ and Cl^- content increased in stock,and Na⁺ and Cl^-content in leaves and roots of ’Chao feng kang sheng wang’ increased less than ’Feng yuan xian feng’and ’FR-jiang jun’,but the absorbency of K⁺,Ca²⁺ were stronger than other varieties.So the results were favor of maintaining natural physiological activities and higher photosynthesis.And all that suggested ’Chao feng kang sheng wang’ suffered the least salt stress and had the best salt tolerance in all watermelon stocks in our experiment.The results indicated that effects of salt stress on stock varieties were different,under salt stress,the growth of ’Chao feng kang sheng wang’ inhibited less,the osmotic adjustment ability and photosynthesis was higher than that of ’Feng yuan xian feng’and ’FR-jiang jun’,and the injury of plant was smaller and had stronger the salt of tolerance.3.Salt-tolerance of ’Chao feng kang sheng wang’ as the stock and ’xiu li’ as the scion was chosen as experimental material,and we studied that the effects of 100 mmol·L^-1 NaCl stress on the growth,photosynthetic parameters,photosystemⅡphotochem（PSⅡ） and K⁺,Na⁺,Ca²⁺,Mg²⁺,Cl^- content in different apparatus of grafted seedlings and scion-root seedling.Main researches were as follows: 1)Salt stress decreased significantly the growth,net photosynthesis（Pn）,stomatal conductance（Gs）,tercellular CO₂ concentration（Ci）,actual efficiency of PSⅡ（ΦPSⅡ） and efficient of photochemical quenching（qP） of grafted seedlings and scion-root seedling,but had less effects on the maximal photochemical efficient （Fv/Fm）.The grafted seedlings were significantly inhibited than the scion-root seedling in the equal salt stress.2) Na⁺,Cl^- content of grafted seedlings and scion-root seedling increased significantly for 9 days in NaCl stress,but that of grafted seedlings was advanced less than that of scion-root seedling,and this could reduce that effects of excessive Na⁺,Cl^- content on photosynthesis and physiological,biochemical activity.The content of K⁺,Ca²⁺,Mg²⁺ in grafted seedlings and scion-root seedling was decreased,but K⁺,Ca²⁺,Mg²⁺ content of grafted seedlings was higher than that of scion-root seedling,this indicated that grafting advanced the choice,movement of K⁺ and Ca²⁺,and improved the effects of excessive Na⁺ on injury in a certain extent.更多还原