Mutagenesis Hybridization And Screening Of Strain Resistant To High Temperature With Mononuclear Hypha Of Lentinus Edodes

Lentinus edodes are medium and low temperature edible fungi.The main production areas of lentinus edodes are Shandong,Henan,Fujian and Anhui,where the summer temperature is much higher than the temperature required for lentinus edodes growth.Under high temperature conditions,lentinus edodes growth is easy to be damaged and restricted,which has irreversible restriction on the growth of mycelium and fruity body.In order to solve the problems of low yield and poor quality of lentinus edeinus under high temperature stress,this study selected 8 different lentinus edeinus edeinus varieties through the initial high temperature tolerance screening,and selected Wuxiang 1 and Lixiang 2 as the experimental materials.The breeding methods of single hybridization and single and double hybridization after mutagenic were adopted for the mononuclear mycelia.According to the characters and performance of mutant hybrid strains,high quality mutant hybrid strains with high temperature tolerance were selected,in order to provide suitable high temperature tolerance strains for the main cultivation area of mushroom.The main results are as follows.1.Wuxiang 1 and Lixiang 2,which had good high temperature resistance and agronomic traits,were selected initially through high temperature.The high temperature inhibition lines of Wuxiang 1 and Lixiang 2 were determined at 48 ℃,and the conditions of temperature rescreening were established as 48℃(2h)high temperature stress and 25℃recovery growth.2.Wuxiang 1 and Lixiang 2 were used as materials to screen the optimal protoplast dilution ratio.The results of protoplast dilution ratio selection test showed that when the protoplast suspension was diluted to 100 times,the protoplast obtained was more conducive to coating and protoplast regeneration and statistics.3.Protoplast regeneration strains were selected by microscopy.A total of 258 protoplast regenerating strains of two original strains were selected before and after,258 regenerating strains were examined by microscopy,and the mononuclear strains detected by microscopy were purified by second mononuclear.The results of the second microscopy were compared with those of the first microscopy,and W34 was found to be a double-nucleated strain.Therefore,the obtained mononuclear strains were W4,W5,W15,W16,W17,W26,W27,L37,L69,and L103.4.Mutagenesis conditions and selection of hybrid parents.In order to obtain more mutant mononuclear protoplasts,combined with the fatality rate curve,the fatality rate of80～90% was selected,that is,the UV irradiation time was 18～22s.Through the comparison of agronomic traits and the growth rate of excellent mutagenic strains,W16-22 and L37-2 were selected as the hybrid parents.The results of single-single and single-double hybridization showed that 28 of the 42 strains were able to form effective lock-like association.5.Screening of superior mutagenic hybrid strains.The antagonism test between hybrids and parents showed that the genetic information of 13 hybrid strains capable of forming antagonistic lines had changed.By analyzing the growth status of the 13 hybrid strains,six mutagenic hybrid strains with good growth status were selected and numbered as A3,A5,A8,A10,A11 and A12,respectively.After esterase isozyme electrophoretic analysis and high temperature screening of 6 mutagenic hybrid strains with good growth conditions,2excellent mutagenic hybrid strains were obtained in this study.