化感物质脂肪酸酯对嫁接西瓜生理生化特性及根际土壤微生态的研究

发布时间：2018-05-01 17:43

本文选题：脂肪酸酯 + 西瓜　；参考：《四川农业大学》2016年硕士论文

【摘要】：西瓜(Citrullus lanatus)属于葫芦科(Cucurbitaceae)西瓜属(Citrullus),一年生蔓生草本植物,是我国的重要蔬菜作物。但由于西瓜栽培面积不断扩大,尤其是在设施条件下的栽培面积,且西瓜极易发生连作障碍。已有研究表明,化感物质的积累会导致西瓜的连作障碍。在实际生产中,人们多利用嫁接来缓解西瓜的自毒作用。有研究指出,嫁接使西瓜根系分泌物中的化感物质发生了变化,改变了西瓜的化感效应,缓解了连作障碍。为此,本课题在研究了嫁接西瓜化感物质组成成分的基础上,选择邻苯二甲酸二辛脂、邻苯二甲酸二异丁酯两种脂肪酸酯类化感物质,以期从西瓜及嫁接西瓜生长、生理特性及土壤生化特性的角度揭示脂肪酸酯类化感物质对西瓜及嫁接西瓜的作用机理以及嫁接缓解西瓜自毒作用的机理,为进一步完善嫁接西瓜增产机理奠定理论基础。本研究结果如下：(1)两种物质对西瓜幼苗生长都存在“低促高抑”的化感作用特点,DOP对西瓜幼苗生长的最佳促进浓度是0.1mmol/L, DIBP的最佳促进浓度是0.05mmol/L,两者浓度在大于1mmol/L时起到抑制作用；两种物质处理下的SOD、POD、CAT活性在5d、10d均有不同程度的增加,其中第10d的促进作用最强,在处理的15d,SOD、POD、CAT活性显著下降,MDA含量在处理15d时显著增加：DOP、DIBP处理均会使脯氨酸含量有不同程度的增加,DOP第15d处理下的脯氨酸含量显著增加,DIBP第10d处理下的脯氨酸含量显著增加。西瓜叶片脯氨酸的含量随着处理浓度的增加而不断升高；高浓度的脂肪酸酯类物质处理后,西瓜叶片抗氧化酶活性降低,植株生长受到抑制。(2)不同浓度DOP、DIBP处理下西瓜叶片叶绿素a、叶绿素b含量叶绿素a/b均有一定程度的提高；在DOP、DIBP处理下,自根西瓜和嫁接西瓜的气孔导度、胞间CO：浓度均有所提高,表明脂肪酸酯能够促进西瓜光合效率,其中嫁接西瓜的三项指标均比自根西瓜高,表明在脂肪酸酯化感物质的作用下,嫁接西瓜的光合效率比自根西瓜强。(3)在DOP、DIBP处理下,自根西瓜和嫁接西瓜的和Fo有一定程度的升高,自根西瓜Fv/Fm下降且均低于对照,嫁接西瓜的Fv/Fm均随DOP、DIBP处理浓度升高呈先增后降的趋势,表明在低浓度的脂肪酸酯化感物质作用下,嫁接西瓜的原初光能转化率比自根西瓜高。低浓度的DOP、DIBP处理使自根西瓜、嫁接西瓜的NPQ有一定程度的下降,但当浓度0.5mmol/L时,NPQ显著上升,说明适当浓度的脂肪酸酯化感物质能使西瓜用于耗散的热量减少,提高光能转化率。当DOP、DIBP处理浓度0.05mmol/L寸,自根西瓜、嫁接西瓜的qP均显著下降,电子传递速率ETR也显著降低,表明脂肪酸酯化感物质使PSⅡ反应中心过剩的激发能使QA被还原程度增加,导致ETR降低,电子传递活性下降。(4)随着DOP、DIBP浓度的升高,嫁接西瓜土壤的细菌和放线菌数量是先增大后减少,真菌数量时先降低后增加。土壤过氧化氢酶、蔗糖酶、蛋白酶活性变化规律为先增大后减小,脲酶活性有一定程度的增大。在DOP、DIBP处理下,嫁接西瓜细菌、放线菌数量均高于自根西瓜,真菌数量低于自根西瓜。嫁接西瓜土壤过氧化氢酶、脲酶、蔗糖酶、蛋白酶活性均高于自根西瓜。
[Abstract]:Watermelon (Citrullus lanatus) belongs to the cucurbit (Cucurbitaceae) watermelon (Citrullus), one of the annual vine plants. It is an important vegetable crop in China. But because of the growing area of watermelon cultivation, especially the cultivated area under the condition of facilities, the watermelon is very easy to have continuous cropping obstacles. In the actual production, people use grafting to alleviate the self toxicity of watermelons in actual production. It is pointed out that grafting makes the allelochemicals in the root exudates of watermelons change, changes the allelopathic effect of watermelons and alleviates the continuous cropping barriers. Therefore, this subject has studied the basis of the composition of the Allelochemicals of the grafted watermelon. On the basis, two symplectic esters of phthalic acid two formic acid, and two isobutyl ester of phthalic acid two formic acid were selected, in order to reveal the mechanism of fatty acid ester allelochemicals on watermelons and grafted watermelons from the growth of watermelons and grafted watermelons and the biochemical characteristics of soil, as well as the mechanism of the grafting of watermelons and grafted watermelons to alleviate the self toxicity of watermelons. The theoretical basis for further improving the mechanism of increasing the yield of grafted watermelon. The results are as follows: (1) the two kinds of substances have the characteristics of Allelopathy of the growth of watermelon seedlings, and the best promoting concentration of DOP on the growth of watermelon seedlings is 0.1mmol/L, and the best promoting concentration of DIBP is 0.05mmol/L, the concentration of both is more than 1mmol/L. The activity of SOD, POD and CAT under the treatment of two substances increased in 5D and 10d, among which the promotion of 10d was the strongest, and the activity of 15d, SOD, POD and CAT decreased significantly in the treated 15d, and the MDA content increased significantly when the 15d was treated. Proline content increased significantly, the proline content increased significantly under the treatment of DIBP 10d. The proline content of watermelon leaves increased with the increase of treatment concentration. After treatment with fatty acid esters, the antioxidant enzyme activity of watermelon leaves decreased and the plant growth was inhibited. (2) different concentrations of DOP, DIBP treated watermelon leaves Chlorophyll a and chlorophyll b content of chlorophyll a/b were improved to a certain extent. Under the DOP, DIBP treatment, the stomatal conductance of self rooted watermelons and grafted watermelons increased, indicating that the concentration of CO could promote the photosynthetic efficiency of watermelon, of which three indexes of grafted watermelons were higher than that of self rooted watermelons, indicating that fatty acids were esterified in fatty acids. The photosynthetic efficiency of grafting watermelon was stronger than that of self root watermelon. (3) under the treatment of DOP and DIBP, the self root watermelon and the grafted watermelon and the Fo had a certain degree of increase, and the Fv/Fm decreased from the root watermelon and lower than the control. The Fv/Fm of the grafted watermelons all increased with the DOP, DIBP treatment concentration increased first and then decreased, indicating that the low concentration of fat was in the low concentration. The initial light energy conversion rate of grafted watermelon was higher than that of self rooted watermelon under the action of esterification. The low concentration of DOP, DIBP treatment made the NPQ of Watermelon Grafted from roots decreased to a certain extent, but when the concentration of 0.5mmol/L, NPQ increased significantly, indicating that the appropriate concentration of fatty acid esters could reduce the heat dissipation of watermelon. High light energy conversion rate. When DOP, DIBP treatment concentration 0.05mmol/L inch, self root watermelon, the qP of grafted watermelon decreased significantly, the electron transfer rate ETR also decreased significantly, indicating that fatty acid esterification substance made the PS II reaction center excess excitation can increase the degree of QA reduction, lead to ETR decrease, and decrease the electron transfer activity. (4) along with DOP, DIBP concentration The number of bacteria and actinomycetes in the grafted watermelon soil increased first and then decreased, and the number of fungi decreased first and then increased. The changes of soil catalase, sucrase and protease activity were increased first and then decreased, and the urease activity was increased to a certain extent. The number of actinomycetes was higher than that of self roots at DOP and DIBP. The number of watermelon and fungi was lower than that of self rooted watermelon. The activities of catalase, urease, sucrase and protease of grafted watermelon were higher than those of self rooted watermelon.

【学位授予单位】：四川农业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S154.3;S651

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