植物内生真菌对镉和盐胁迫下水稻幼苗缓解作用的研究

发布时间：2018-08-09 07:10

【摘要】：重金属镉(Cd)以及土壤盐碱化是制约我们国家粮食总产量的重要因素之一。水稻是我国主要的粮食作物,缓解重金属和盐对水稻的伤害成为急需解决的问题。本文利用从碱蓬叶内分离出来的碱蓬内生真菌高Y1-1对辽星1号水稻种子进行处理,首先用不同浓度的菌液(0,5%,10%,15%,20%,25%)处理水稻种子,筛选最适菌液浓度。然后将水稻分为两组内生真菌侵染组(E+)和内生真菌未侵染组(E-),分别用浓度为50μM CdCl2、100 mM NaCl进行单一胁迫以及联合胁迫处理,从水稻幼苗的生长指标、光合色素、抗氧化系统以及渗透调节物质含量的变化趋势等分析内生菌对Cd和NaCl胁迫下水稻幼苗抗性的影响。主要研究结果如下:1.在种子时期内生真菌侵染促进水稻生长的最适菌液浓度是10%;2.镉和NaCl胁迫下水稻幼苗的株高及根长均比对照小;内生真菌菌液侵染水稻种子后,Cd和NaCl处理水稻幼苗,E+显著高于E-株高;联合胁迫时,E+根长显著高于E-;3.E+组水稻幼苗的叶绿素a、b含量要明显高于E-;E+组水稻幼苗的类胡萝卜素含量比E-组高;4.在内生真菌未侵染水稻种子时,Cd和NaCl胁迫水稻幼苗后,水稻幼苗叶片的SOD、CAT和POD活性均明显减弱;在内生真菌侵染水稻种子后,水稻幼苗叶片的SOD、POD及CAT活性均高于E-;5.在未加菌时,Cd和NaCl胁迫下的水稻幼苗脯氨酸含量升高,而可溶性糖及可溶性蛋白含量降低;随着水稻生长时间的延长,水稻幼苗的脯氨酸含量和可溶性蛋白含量逐渐增加,可溶性糖含量逐渐减少;当内生菌侵染水稻后,水稻幼苗的脯氨酸含量要低于E-,而可溶性糖及可溶性蛋白含量均大于E-;6.未加菌处理的水稻幼苗在受到Cd和NaCl的胁迫后,超氧阴离子含量增加,过氧化氢含量升高以及丙二醛含量增加;而内生真菌侵染水稻种子后,水稻幼苗的超氧阴离子含量、过氧化氢和丙二醛含量低于E-。
[Abstract]:Cadmium (Cd) and soil salinization are one of the important factors restricting the total grain yield of our country. Rice is the main food crop in China. It is urgent to solve the problem of alleviating the damage of heavy metal and salt to rice. In this paper, the rice seeds of Liaoxing No. 1 were treated with the endophytic fungus of Suaeda salsa, Y1-1, which was isolated from the leaves of Suaeda salsa. Then, the rice was divided into two groups: (E) and E-, which were infected by endophytic fungi. The rice was treated with 50 渭 M CdCl2100 mm NaCl and combined stress respectively. The growth index of rice seedlings, photosynthetic pigments, were analyzed. The effects of endophytic bacteria on the resistance of rice seedlings under CD and NaCl stress were analyzed. The main results are as follows: 1. The optimum solution concentration of endophytic fungi to promote rice growth in seed stage was 10 ~ 2. The plant height and root length of rice seedlings under cadmium and NaCl stress were smaller than those of the control, and the plant height of rice seedlings treated with CD and NaCl was significantly higher than that of E- plants after infecting rice seeds with endophytic fungi solution. Under combined stress, the content of chlorophyll a b in rice seedlings of E 3. E group was significantly higher than that of E 3. E group, and the carotenoid content of rice seedlings in E E group was 4% higher than that in E group. When endophytic fungi did not infect rice seeds, the activities of POD and cat in leaves of rice seedlings decreased significantly after CD and NaCl stress, and the activities of CAT and POD in leaves of rice seedlings were higher than those of E-5 when endophytic fungi infected rice seeds. Under the stress of CD and NaCl, the content of proline increased, but the content of soluble sugar and soluble protein decreased, and the content of proline and soluble protein increased gradually with the increase of rice growing time. The content of soluble sugar decreased gradually, and the proline content of rice seedlings was lower than that of E-while the content of soluble sugar and soluble protein was higher than that of E-6 when the endophytic bacteria infected rice. Under CD and NaCl stress, superoxide anion content, hydrogen peroxide content and malondialdehyde content in rice seedlings were increased, but superoxide anion content in rice seedlings was increased after endophytic fungi infected rice seeds. The contents of hydrogen peroxide and malondialdehyde were lower than that of E-.
【学位授予单位】：沈阳师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S511

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