The Research On Screening The Am Fungi For Growth Effect And Biocontrol Efficacy Of Different Crops And The Mechanism Of Fruit Lycopene Promotion

Arbuscular mycorrhizal fungi(AMF)Arbuscular mycorrhizas,which are symbiotic associations between underground organs(mainly roots),are the most common and widespread fungi in the world.Previous research found that AMF could bring benefits for lots of plants,such as growth promotion and biocontrol effect.It also helps the plant with environment strees and promoting fruits quality.In the face of the nature of the bioticl and abiotic stress,AM fungi provides better protection for the plant.It can help the plants absorb the soil nutrient elements,such as N,P.It can modifies the plant roots morphology enlarged the surface absorb area of nutrients and water.AM fungi improves fruits quality of many kinds of plants,mainly improve the nutrition and flavor of the fruit.In today's society,all kinds of chemical pesticides and fertilizers are widely used,putting a theat to human health.AM fungi is eco-friendly,and can reduce the pesticide residue and heavy metal residues in the soil,so it is a potential source of biological pesticides and fertilizers.Acoording to the difference of morphology and physiology,AM fungi can be divided to the different groups.The effect of growth promoting and biocontrol is also different.So it is neccssary to screen the most suitable AMF for different kinds of plants.In this research.11 kinds of crops and 4 kinds of AMF were selected to screen the special AM fungi for different crops,and to provide the theoretical basis for the further application of AMF.In this research,we inoculated 4 kinds of AMF to pick up one which had better growth promoting and biocntrol effect.Results showed that showed biocontrol effecacy of two kinds of AM were 82.8%.Acaulospora spinosa XJ21 showed good growth promoting effct among all the AMF.It increased the tomato biomass by 36.2%.According to the two greenhouse experiments results together,Acaulospora spinosa is a promising AMF which could be used on tomato plants.Our previous results showed that Arbuscular mycorrhizal fungi(AMF)Acaulospora spinosa XJ27 could promote plant growth and biocontrol efficacy of tomato bacterial wilt.We inoculated AMF XJ27 on tomato seedling,and transplanting them to the field.After 30d,we determined the survival rate and biomass of different treatments.Results showed that AMF treatment had increased the biomass and survival rate of tomato.We have tested the leaf sample of disease plants,it has been diagnosed as Tomato yellow leaf curl disease(TYLCD).TYLCD is an important disease of tomato,having frequently caused 100%yield loss of tomato plants grown in tropical and subtropical regions After determination of disease severity,the results showed that AM fungi XJ27 has a certain biocontrol effect of tomato yellow leaf virus disease,which is of 50.44%.For further research,we have inoculated Acaulospora spinosa on tomato 'Micro Tom'.Micro-Tom is a miniature dwarf tomato,which has a short life cycle,so it is suitable for molecular biology study.After determination to a series of indicators,we found that the biomass and yields of XJ27 group was higher than the control group.And indicators that affect the nutrition and flavor of the fruits treated by XJ27 were higher than the control group.And the lycopene content treated by XJ27 group was increased by 44.6%compared to the control as well.The expression of lycopene synthesis related genes psyl and psy2 was earlier and stronger than the control group by semi-quantitative PCR results showed.Due to the ability of growth promotion and increasing the content of lycopene,our study suggested that XJ27 has the potential for application and further study.