Regulated Influences Of Different Concentrations Of Exogenous Put On Root Architecture And Arbuscular Mycorrhizal Development Of Trifoliate Orange

In potted and greenhouse conditions, using trifoliate orange(Poncirus trifoliate) seedings as material, we researched the effects of different concentrations of Putrescine(Put)(0,0.05,0.1,0.5,1mmol/L)and arbuscular mycorrhizal on the growth of Poncirus trifoliata seedings, root architecture, mycorrhizal development and sugar content of plant. Experimental treatment after three months, determined the plant height, stem diameter, leaf number, chorophyll content, fresh and dry weight of shoot and root, mycorrhizal development stituation, main root lenght, lateral root number, root morphology, sucrose and glucose contents. The study also discussed the relation of exogenous Put, mycorrhizal and root architecture.In this experiment, inoculated arbuscular mycorrhizal fungi (Glomus mosseae) in the soil of planted trifoliate orange(Poncirus trifoliata), using different concentrations of exogenous Put to deal with trifoliate orange (Poncirus trifoliata) after three months, processing once a week, end of the experiment after processing75days, the harvest plant to observe the growth of the arbuscular mycorrhizal status. Results showed arbuscular mycorrhizal fungi infected the roots of trifoliate orange(Poncirus trifoliata), whether it is the main root, first lateral root and second lateral root or third lateral root, they were infected. Mycorrhizal colonization of mycorrhization in trifoliate orange (Poncirus trifoliata) seedings with treatments of different concentrations of exogenous Put were higher than no treatment, the effect of exogenous Put at the level of0.05mmol/L was most obvious. It seems that in the case of a suitable concentration, exogenous Put can stimulate the growth of mycorrhizal, could play a better role.Good root architecture is very favorable for plant. Promoting plants to form good root architecture has become a research focus of modern science. The root architecture in the process of formation was influented by various factors, such as soil, climate and human factor. At present, the study of root architecture focuses on hormones, but the research of the effect of soil microorganisms and exogenous Put for the root architecture was less. In this experiment, root length, root surface area, root projected area, root volume mycorrhization in trifoliate orange(Poncirus trifoliata) seedings has been significantly improved, the effect of the inoculation and exogenous putrescine treatment for the index of root architecture were much more obvious than the onlone inoculation, however, the between of different concentrations of exogenous Put have not significant difference; Moreover, dual processing of inoculation of arbuscular mycorrhizal fungi and exogenous have positive effect to improve the root architecture of trifoliate orange (Poncirus trifoliat) seedings, application of Put stimulated root tip cells division, promote root branching and lateral root developing, especially the secondary lateral root, the amount increase largely, and the effect of exogenous Put at the level of0.05mmol/L was most obvious. This showed that appropriate concentration of polyamine has positive effect for root architecture.In this experiment, the inoculation of arbuscular mycorrhizal fungi (Glomus mosseae) significantly enhanceed the growth of trifoliate orange (Poncirus trifoliata) seedings, and the effect was more obvious after treatment with exogenous Put. Plant height, stem diameter, leaf number, shoot and root dry weight and fresh weight significantly improved after treatment with exogenous Put, and the effect of exogenous Put at the level of0.05mmol/L was most obvious. This showed that appropriate concentration of polyamine has positive effect for trifoliate orange (Poncirus trifoliat) seedings growth.Arbuscular mycorrhizal fungi as heterotrophism microbes, by absorbing pentose from the host plants complete their life cycle, at the same time, it can provide plants with nutrient and moisture transport channels and helps the plants absorb more moisture and mineral nutrition. In this experiment, we found that the sucrose contents of trifoliate orange(Poncirus trifoliata) seedings shoot and root after treatment with appropriate were significantly lower than no treatment with appropriate, therefore, the glucose content in the trifoliate orange(Poncirus trifoliata) seedings was opposite. We also found that both glucose and sucrose, and the difference of their content changes between in different concentrations of polyamine treatment is not large, and the difference of the sucrose content between shoot and root also do not have too big difference, therefore, the concentration of exogenous putrescine was not the main factors that result in the change of sugar content in plants. Due to sucrose in acidic conditions, dissolves readily converted to glucose and fructose for mycorrhizal fungi absorb to use, so sucrose content showed a decrease trend. Sugar content rise can provide more carbon source for the formation of root architecture.Exogenous polyamine can promote the host plant roots and arbuscular mycorrhizal fungi form symbiotic structure, and arbuscular mycorrhizal fungi can promote the host plants to absorb water and nutrients. The leaf is the main place of plant photosynthesis, and the strength of the photosynthesis was affected by plant chlorophyll content in the plant. In this experiment, we found that after the dual processing of exogenous polyamine and arbuscular mycorrhizal fungi, the chlorophyll a, chlorophyll b, carotenoid and total chlorophyll content of trifoliate orange (Poncirus trifoliata) seedings leaves were increased significantly, when the concentration of exogenous putrescine was0.05mmol/L, the increased range of the chlorophyll content was maximum. Increase of chlorophyll content was related to arbuscular mycorrhizal fungi and exogenous putrescine, putrescine promote the formation of mycorrhizal to absorb more water and nutrients, so as to promote the growth of plants and the formation of chlorophyll.In conclusion, many internal and external factors affected the change of plant root architecture. The test results showed that the double treatments of exogenous putrescine and arbuscular mycorrhizal fungi can significantly improve the mycorrhizal colonization, increase the content of soluble sugar, promote the root tip cell division and the formation of lateral root, it had the beneficial effects on growth space for plant root, and facilitate its absorption of moisture and nutrients, which provided more beneficial environment for plant growth and development.