Study On The Identification And Cultivation Characteristics Of Molds In Walnut From Xinjiang

In this paper,Xin 2 walnut is used as raw material,through the separation,purification and identification of polluting walnut mold,to study the main types of polluting mold.And through metagenomics sequencing to further analyze the diversity of microorganisms in the samples and related functional genes.Finally,the mold is cultured in liquid The active oxygen metabolism index of the silk body is detected,and the culture characteristics of the mold are analyzed,which provides a reference for the research and prevention of the quality deterioration of thin-skinned walnuts.The results of the study are as follows:（1）Understand the mold contamination of Xinjiang thin-skinned walnuts and the types of contaminated microorganisms.The contaminated mold was separated and purified by the dilution coating method and the three-point method,and the method was identified by a combination of morphology and ITS sequence molecular analysis.The results showed that there are 10 kinds of molds contaminated by thin-skinned walnuts.According to the growth characteristics of the strains,Rhizopus oryzae,Trichoderma atroviride,Aspergillus niger and Aspergillus flavus are the dominant molds that affect the quality of walnuts.The other six molds are Penicillium expansum,Fusarium solani,Fusarium verticillioides,Earliella scabrosa,Penicillium dierckxii,and Alternaria alternata.（2）Through the metagenomic technology,it is possible to obtain all the genetic data of the microorganisms in the thin-skinned walnuts in Xinjiang,use the database to compare,conduct certain analysis and research,explore the composition of the microorganisms in the thin-skinned walnuts,and analyze the physiological functions and metabolic mechanisms on the basis of genes.And the metabolic mechanism.The results showed that a total of 168,970,360 reads were obtained from genome sequencing,and 362,250 scaffolds were assembled.And through the analysis of species annotations,the main microorganisms in contaminated thin-skinned walnuts are Nectria haematococca,Alternaria alternata,Ascochyta rabiei,Diplodia seriata,Pantoea sp and Macrophomina phaseolina.In addition,the main genes involved are related genes in the secondary metabolic pathways of carbohydrate metabolism and amino acid metabolism in the metabolic pathway.（3）In order to study the growth characteristics of walnut isolated molds,a liquid medium with walnut as a nutrient substrate was used as the experimental group,while potato dextrose broth medium was used as a control group to study the changes in mycelial active oxygen metabolism-related enzyme activities during the culture process law.The results showed that the O₂^-、GSH、MDA、GR、SOD and APX of each experimental group and the control group showed a trend of first increasing and then decreasing,POD showed a continuous decreasing trend,and H₂O₂content showed a decreasing-increasing-decreasing trend.The activity of group A（walnut milk）was higher than that of the control group;CAT showed a trend of increasing and decreasing,and the activity of the control group was slightly higher than that of group A（walnut milk）.This indicates that the activity of antioxidant enzymes can be significantly improved when the mycelium is cultured in the liquid of group A（walnut milk）.