Mycorrhizal Rape (Brassica Napus L.) And The Effect On Yield And Quality

As a new sort of biologic fertilizer, arbuscular mycorrhizal fungi (AMF) exists in almost all kinds of soils and forms symbiosis with nearly all families of the angiosperms. Most of the crops, fruit trees, vegetables, ornamental plants and flowers can form arbuscular mycorrhizae.The function of AM fungi between plant and soil is being a bridge, and it is the carrier of matter transport. As the carrier of matter transport from plant to soil or from soil to plant, it is very important to the development and health of plant and soil.Plant mycorrhiza and mycorrhizal fungi are being studied in many countries because of their significance in sustainable agriculture and reconstructive ecology recently. It have been confirmed that AM fungi could improve plant growth by increasing uptake of the water and mineral nutrient, increase plant resistance to several soil-borne root pathogens and tolerance to adverse circumstances. AM fungi also plays an important role in conservation of soil. Inoculation with AM fung can stimulate establishment of seedlings, increase output and improve quality. Consequently, AM fungi has important meaning and broad application in both of the ecosystem reconstruction and the maintenance for ecologic balance.Rape belongs to the Brassica of Cruciferae, is a kind of annual plants and one of the most important oil crop in the world. Cultivation area of rape in Asia is 70% of the whole world's. China, Pakistan and India made rapes as their major sources of edible oil. China has the the lagest cultivation area and the most output in the world. Rape is also one of the most important economic crop in Three Gorges reservoir area.Rape contains three cultivated species: Brassica napus L., Brassica juncea Czern.et Coss and Brassica campestris L.. Because of Brassica juncea Czern.et Coss and Brassica campestris L. has a lower output, lower oil content, and weaker adversity fastness, so Brassica napus L. has the highest economic value and the lagest planted area. This experiments get two species of Brassica napus L. as its material: Zhongyou821 (black seeds) and Yuhuang NO.l(yellow seeds).Normaly, Cruciferaea plants were treated as non-host plant, can be barely inoculated by AM fungi. Although there are few expetiments report that some Cruciferaea plants can form mycorrhiza in recent years, reports about rape's mycorrhiza was not seen. So we designed poted and field experiments about that two species of Brassica napus L. innocated with AM fungi, in order to discuss the ability and possible effect of the conolization of AM fungi in Brassica napus L. Pot experiments were conducted first, in order to observe that is there simbiosis between rape and AM fungi. To eliminat the disturbance from other microbe in soil, experiment was done in axenic environment. Before experiment, all the seeds were surfacely sterilized, soil was radiate sterilized, and growing seedlings phase was progressed in axenic room. Pot experiment's result shows that rape inoculated with AM fungi could be colonized effectively and form mycorrhizae, in which arbuscular, vesicles, hyphae and other configuration can be clearly observed. Infection rate of all the inoculated treatments were more than 30%, and the treatments inoculated with Glomus mosseae have a higher infection rate than that with Glomus versiforme. Experimental result showed that rape root tip didn't have immunity against AM fungi, there is Well nutritious interaction between AM fungi and cortical cells in the rape root. Because we didn't know whether the AM fungi could inoculate rape, so the chief purpose of this experiment is to observe inoculation. But from a few measurements we can see that, in every phases of rape's growth, inoculated treatments had an obvious advantage than countrol in growing. It shows it's possible that there is mycorrhizal dependence for rape. So we conduct field experiment followly, to deeply discuss the relationship rape and AM fungi, observe the effect on growth and quality of rape.Then, we use soil ball to raise seedlings in field experiment. Soil has been sterilized and seeds been disinfected before. After seedlings raiseing, we moved the seeds within soil balls to field. In the whole cultivation we adopted conventional management, periodic observation, mearment, note and take pictures. After harvest and measurement, it showed that rape grow in field also can symbiose with AM fungi and form mycorrhiza, infection rate is more than 30%. Experimental result showed that AM fungi could promote growth of rape obviously. Compare with the countrol, the hight, ground diameter, leaf area, dry weight and anthotaxy number et al. of inoculated treatments were promoted more or less. Oil seeds of inoculated treatments had been increased visibly, but two data of oil seeds' quality. AM fungi can also promote the absorb of microelement in rape, especially the element phosphorus. Comparison between inoculated treatments, Glomus mosseae have a better effect than Glomus versiforme.This research is significant for probing the relationship between crucifer and AM fungi. It will offer an academic foundation for the application of AM fungi in rape's yield, exploit an important investigative direction to improve output and quality of rape.