Study On Improving The Yield Of Sweet Corn Via Arbuscular Mycorrhizal Fungi

Arbuscular mycorrhizal(AM)fungi are kinds of endogenous mycorrhizal fungi,which can be establish symbiotic relationship with many terrestrial plants.The extraradical mycelium(ERM)can extend in soil,and expand the root absorption area,thus facilitating the absorption of mineral elements,especially nitrogen and phosphorus on host plants.Nitrogen and phosphorus are the nutrient-limiting elements for plant growth.The form and concentration of nitrogen and phosphorus will affect AM fungi growth.At the same time,which also affect nitrogen?phosphorus absorption and transport in the symbiotic system.Zea Mays L,as a kind of nutritious new corn,have a long history,many varieties,and wide planting in Jinhua.The abuse of pesticides and fertilizers are causing serious pollution of soil and water resources.The production of sweet corn facing dual task,increase yield and improve quality.AM fungi,as a kind of“bio-fertilizer”,were applied to sweet corn planting,which would be of great help for sweet corn production.In this experiment,AM fungi were inoculated to sweet corn as the host plant in different exogenous conditions.The growth of mycorrhizal sweet corn?nitrogen and phosphorus contents?polysaccharide and protein contents and composition were detected.The study on application of arbuscular mycorrhizal fungi in improving the yield of corn,would include the following aspects.(1)The experiment used KH2PO4 as the phosphorus source,designing five concentration gradient(0 mg/L?20 mg/L?40 mg/L?80 mg/L?160 mg/L,marked PO?P20?P40?P80?P160).The effect of different phosphorus concentration on growth of mycorrhizal sweet corn seeding was investigated.Results showed:The colonization rate in low phosphorus concentration(PC)was higher than in high PC.The numbers of spores were increasing with the improve of PC.The fresh weight of the external hyphae inside the chamber in P40 was the highest.The biomass and nitrogen?phosphorus contents.in shoots and roots of mycorrhizal sweet corn were obviously higher than control groups.More over,low PC significantly promoted the increment of fresh weight in shoot and mycorrhizal root of sweet corn.The total N contents in shoots and roots of mycorrhizal sweet corn were highest in P40?P80 and P20.P40.The total phosphorus contents in shoot and root of mycorrhizal sweet com were highest in P80 and P160.Arg content in mycorrhizal root was highest in low PC(P20).This study revealed phenomenon that the sweet corn growth was promoted by inoculating arbuscular mycorrhizal associating with the exogenous PC.(2)The growth of mycorrhizal sweet corn seeding was studied by adding different nitrogen sources in the hyphae chamber(4 mmol/L),including Arg?NH4NO3?Urea?Glu.Results showed:AM fungi significantly promoted the growth of plant?the absorbing of nitrogen and phosphorus.When using Arg as nitrogen sources,the colonization rate,Arg content in mycorrhizal root was higher,and the biomass of mycorrhizal sweet corn was higher.The total nitrogen contents in shoots were highest in Urea?NH4N03?Arg.The total phosphorus contents in shoots and the nitrogen?phosphorus contents in roots were higher in Urea.This study revealed that the nitrogen sources of Urea was more conducive to the growth of mycorrhizal sweet corn seeding.(3)The colonization rate of mycorrhizae and the growth?corncob and quality of mycorrhizal sweet com were studied by adding different organic matters to the culture substrates,including peat?marl and organic fertilizer.Results showed:The weights of corncob and plant under organic fertilizer were obviously higher than other groups,meanwhile,the amount of total phosphorus in arbuscular mycorrhizal sweet corn seeds was highest,but the height of seeding was lowest.Moreover,the amounts of soluble sugar and starch in arbuscular mycorrhizal sweet corn seeds were highest under marl,the soluble sugar was mainly composed of glucose?sucrose and fructose;The total nitrogen and protein in seeds and Arg in mycorrhizae were higher under marl and peat.Moreover,16 kinds of amino acid components were detected in the peat and control groups,and the total amino acid contents in the peat group were higher than that in the control group.This study revealed the great significances of different organic matters in promoting the growth and quality of sweet corn.(4)Onion growth cycle is short,its roots are small and developed,which can form a better symbiotic relationship with AM fungi.In this experiment,AM fungi were inoculated to the host plants onion.When the colonization rate were up to 60%,the sweet corn were plant in the onion growth substrate.The effect on mycorrhizal sweet corn by letting onion cultivation with corn.Results showed:In first week,the infection rate of mycorrhizae?biomass?nitrogen and phosphorus content were not significantly improved compared with the control groups.In second week,the infection rate of mycorrhizae remarkable higher than the control group.In third and forth week,the sweet corn biomass,such as,the fresh weight in shoot and root?root-shoot ratio?nitrogen and phosphorus content were higher than control groups.These result indicated that the method of onion cultivation with corn could promote the inoculation of sweet corn root with AM fungi,then improve the rate of plant growth.