Classification Of A Wild Aromatic Mushroom In Yanshan Mountains And Analysis Of Its Fragrance Components

An aromatic Lactarius sp.,called "Xiaoxiangme",is a kind of wild edible fungi in the Yanshan Mountains of the eastern Hebei province.The dried edible fungi has been used as condiment to cook food for a long time.However,the taxonomic status,cultivation and aroma components have not been reported.In this study,a combination of morphology and molecular biology was used to classify and identify three typical specimens.The results showed that the aromatic Lactarius sp.was classified into Lactarius subzonarius.Then,33 different morphological specimens,collected from 4 counties in the Yanshan Mountains,was classified into 3 groups by intraspecies genetic diversity analysis based on ITS sequences.Haplotype diversity was analyzed by DnaSP 5.0 software based on ITS PCR sequence and cloned sequence,the results showed that 33 haplotypes were harbored in L.subzonarius form Qinhuangdao.Haplotype diversity and nucleotide diversity was 0.854 and 0.00282,respectively.The standard deviation of haplotype diversity was 0.016.Microbial separation technology and molecular biology identification technology were used to study the microecology(rhizosphere microorganisms and endophytic microorganisms)related to the growth and development of Lactarius deliciosus.10 kinds of rhizosphere bacteria,10 species of rhizosphere fungi and 6species of endophytic fungi were identified by microbial separation technology and Molecular biology technology.The solid phase microextraction technology(SPME)coupled with gas chromatography-mass spectrometry(GC-MS)was used to analyze the volatile components of Lactarius deliciosus.A total of 25 volatile components were detected,including 3 oxetane compounds,1 aldehyde,13 esters,3 olefins,2 aromatic compounds and 3 alkanes.The relative content of 3-hydroxy-4,5-dimethyl-2(5H)-furanone,which is the volatile component of fenugreek,is 35.76%.This component is the main fragrance compound of its related species Lactarius helvus It is speculatedthat 3-hydroxy-4,5-dimethyl-2(5H)-furanone is its key fragrance component.