Study On The Effect Of Inoculation With Arbuscular Mycorrhizal Fungi On The Root Growth Of Pyrus Plant And Synthesis Of CTK

The study of Arbuscular mycorrhizal fungi has always been the focus of mycorrhizology, and Arbuscular mycorrhizal fungi promoted on a variety of plant growth, such as arbuscular mycorrhizal fungi effect on the growth of the peony and physiological indicators, and mineral nutrition and growth of the grape cuttings seeding, and so on. In recent years, the study of plant hormone are becoming incandescent, some researchers studied the effect of plant hormone on crop growth from the point of view of physiological and biochemical; some others studied plant hormone mechanism from molecular. But the study that combined arbuscular mycorrhizal fungi and plant hormone is very rarely. Arbuscular mycorrhizal fungi directly acts on the roots of plants. During growth, root tip will also synthesis some cytokinins, such as zeatin, zeatin riboside, then transported upward to the site of action. The infection site of arbuscular mycorrhizal fungi and the synthesis parts of cytokinin are both the root tip, the mutual influence between arbusucular mycorrhizal and cytokinins has not been reported. Meantime, the study of the effects of arbuscular mycorrhizal fungi on ZR and6-BA in the roots, which need continuate, especially in practical applications. The test studied the effects of exogenous cytokinin on root growth and environment of rootstock seedings of Pyrus betulaefolia, which will lay the foundation for production practices in the future.In this study, the test material is rootstock seedings of Pyrus betulaefolia. The treatments of agents are Glomus intraradices, Glomus mosseae, Glomus versiforme, and a blank control group. Randomized block arrangement, and repeated three times. Through index determination of physiological and morphological, the test drawn an agent of the most beneficial to the growth of the rootstock seedings of Pyrus betulaefolia, and drawn the arbuscular mycorrhizal fungi, which have the most impact on the content of CTK in the roots, and determine the significant different among the agents. And the test looks for a method of high-performance liquid chromatography of the most suitable determined the amount of ZR. Through the applied external cytokinin, the test studies root growth of rootstock seedlings and changes of roots in the environment, and explores the role of the applied external cytokinin to the growth of roots. The major results of the trial are as follows:1. After inoculating arbuscular mycorrhizal fungi, during the second peak of root growth(from the early May to the early July), the test obtained the result by measuring root physiological indicators:the growth situation of rootstocks seedings was better in late June than late July, better in late July than the late August, which was in accordance with the root growth cycle.2. Arbuscular mycorrhizal fungi could significantly infect rootstock seedings of Pyrus betulaefolia in the test, and had significant differences between the different inoculation treatment groups. The treatment group of the hightest infection rate is Glomus intraradices, the lowest is Glomus versiforme. The exogenous cytokinin is able to influence the infection rate of mycorrhizal fungi on rootstock seedings of Pyrus betulaefolia, and conducive to the formation of mycorrhizal. The infection rate of inoculated arbuscular mycorrhizal fungi under the exogenous cytokinin is higher than no-exogenous cytokinin.3. Arbuscular mycorrhizal fungi can significantly promoted the growth of rootstock seedings of Pyrus betulaefolia. Inoculated arbuscular mycorrhizal fungi could increase absorption of nutrition elements N, P, K of Pyrus seedings, and had an important role in improving the nutrient levels of Pyrus N, P, K. The exogenous cytokinin had significantly promoted the growth of Pyrus seeding, and the content of mineral elements N, P, K is more than no-exogenous cytokinin, and promoted accumulation of N, P, K of seeding.4. Arbuscular mycorrhizal fungi could significantly improve the microenvironment of roots growth of rootstock seedings of Pyrus betulaefolia through changing soil available N, P, K and soil enzyme activity in the root environment. Exogenous cytokinin is more significant to the improvement of rootstock seedings roots microenvironment, and the content of soil available N, P, K and soil enzyme activity higher than the treatment group of no-applied external cytokinin.5. Optimization of root microenvironment conditions is more conducive to the growth of the arbuscular mycorrhizal fungi. The number of fungi of the treatment groups of the applied external cytokinin is more than the treatment groups of the no-applied.6. Established determination of ZR content of Chromatograph conditions:Column: Shim-Park C18VP-ODS (150mm@4.6mm,5mL); mobile phase was V (methanol):V (solution)=45:55; detection wavelength:268nm; flow rate:0.15mL/m in; injection volume of10uL; column temperature:25℃.Using isocratic elution mode,30minutes.7. Inoculating arbuscular mycorrhizal fungi increase cytokinin content in the roots, and the applied external cytokinin have more pronounced effects on rootstock seedings growth. Among the microbial agent treatment groups, the number of fungi inoculated Glomus intraradices is more than Glomus mosseae, the least is Glomus versiforme.