Breeding New Strains Of Volvariella Volvacea By Molecular Marker-assisted Hybridization Breeding Technology

Volvariella volvacea is a famous edible fungus grown in tropical and subtropical high temperature and rainy areas with high temperature and rainy environment.It has delicious taste,high nutritional value and high economic benefits.China is the biggest producer of V.volvacea.However,the growth of V.volvacea requires high temperature and high humidity environment,so the yield is low,with only about 20%biological efficiency,but the energy consumption of artificial cultivation in winter is relatively high.The above problems seriously hinder the rapid development of its industry.At present,the new strains of V.volvacea are updated slowly.Based on this,the cross breeding of V.volvacea is carried out,which provides theoretical basis and practical reference for the research of V.volvacea breeding.In this study,the new strains of low temperature and high yield of V.volvacea were bred by using mating type gene molecular marker assisted hybridization breeding technology.After several times of cultivation and fruiting experiments,we finally screened and identified a high-yield straw mushroom strain Tai A,and conducted hybridization experiments with low-temperature-resistant straw mushroom strains VH3 and VV039,in order to cultivate a series of low-temperature-tolerant and high-yield new straw mushroom strains,and completed the preliminary screening of potential new varieties of straw mushroom,and the amino acid content of parents and hybrid strains was qualitatively and quantitatively analyzed.The results of this study were as follows:1.Comparative cultivation experiment of the tested strains.The agronomic traits of V.volvacea,such as mycelia growth rate,fresh weight of individual fruiting body,primordial appearance time,large collection date,transverse and vertical diameter of fruiting body,thickness of fungal membrane and biological efficiency were observed respectively.Through the comparison of agronomic traits,the strains with high yield,good fruiting body traits and difficult to open umbrella were selected as hybrid parents.After comprehensive consideration,VV039,VH3 and Tai A were finally selected as hybrid parents.2.The mating type genes types of the tested strains were mainly A1A2,A1A3,A2A4,A3A4,A3A5,A4A5 and A5A6.The mating type gene type of PY1 and Thai A was A1A2,VV039 was A1A3,VV061 was A2A4,VH3,0229,Jinshan wild,V23,JN-V,V27 and V11 were A3A4,N1V3-1 was A3A5,VN24-1 was A4A5,Thailand NO.1 was A5A6.3.Through the isolation of single spore strains,15,20 and 14 single spore strains of parent strains VH3,VV039 and Tai A were obtained,respectively.The mycelia growth rate and colony morphology of these single spore strains were measured.4.A total of 200 possible hybrids gotten by crossing VH3 with Tai A,and 45 true hybrids were obtained by mating type gene and fruiting cultication verification.A total of 210 possible hybrids were obtained by crossing VV039 with Tai A,and 15 true hybrids were obtained by verification.Two strains with low temperature tolerant and high yield were obtained by hybridization of VH3 and Tai A,and the biological efficiency were higher than those of the parent strains,which were H8T7 and H13T7,respectively.VV039 and Tai A failed to obtain higher biological conversion rate than the parent strain,but the biological efficiency of two hybrid strains was close to that of the parent strain,namely strain V3T11 and V3T12.5.Furthermore,the contents of free and hydrolyzed amino acids in parental strains VH3 and Tai A and hybrid strains H4T7,H8T5,H8T7,H9T2,H9T7,H10T5,H13T3 and H13T7 were quantitatively and qualitatively analyzed.Among them,the free and hydrolyzed amino acids of the hybrid strains H8T7 and H10T5 were better than that of parent strains.The total free amino acid contents of the parent strains VH3 and Tai A were 16.33 mg/g and 16.35 mg/g,respectively.The hydrolyzed amino acid contents were 272.18 mg/g and 275.68 mg/g,respectively.The total free amino acid contents of the hybrid strains H8T7 and H10T5 were 19.68 mg/g and 28.59 mg/g,respectively.The total hydrolyzed amino acid contents were 280.87 mg/g and 299.34mg/g,respectively.