The Single Spore Crossbreeding And Genetic Analysis Of Agaricus Bisporus

Along with the rapid development of Agaricus bisporus industry, There is an urgent demand in production is that new varieties agaricus hisporus replace existing varieties that have already used for many years. To efficiently decrease the identify work and cost of the fruiting test and to increase the rate of breeding, the breeders devoted themselves to searching the fast prediction method of identify new cross-breeding strains. In recent years, With the development of molecular biology, all kinds of molecular markers are also starting to using in identifying new cross-breeding strains and the rate of breeding is increased.The objective of this research was to breed new excellent strains of Agaricus bisporus by the technique of single spore crossbreeding. The parent strains of Agaricus bisporus were F56, As2796 and ZN1.41 homokaryon strains were obtained which were matched 420 combinations.11 crossbreeding strains were obtained from these combinations. In this research, Inter-simple sequence repeat (ISSR) was used to analyse the eleven crossbreeding strains and their parents strains, Genetic similarity coefficient and the dendrogram were obtained by NTSYS-pc 2.10 software. Ten ISSR primers which could amplified clear and polymorphic bands could be used to amplify the genomes of all these test strains, and 40 clear and stable fingerprint maps with strong polymorphism were gained. The result showed that the similarity coefficients of the fourteen strains ranged from 0.6700 to 1.000. When the similarity coefficient is 0.8140, fourteen strains were separated in 4 clades. The similarity coefficient of AG95 and F56 is 1.000.These results showed that AG95 was not the true crossbreeding strains and other strains which were different from their diverse parents were the new crossbreeding strains. The excellent crossbreeding strain AG97 was selected from all of the strains through cultivating.In this research, forty monosporous strains that were F2 generation and two strains of tissue isolation were from the crossbreeding strain AG97. The genetic analysis of the F2 generation by ways of ISSR technique and fruiting test and determination of colony form and growth rate.The results of ISSR showed that the similarity coefficients of the forty-five strains ranged from 0.4250 to 1.000. The similarity coefficient of AG97 and its tissue isolation strains AG97-1 and AG97-3 was 1.000, which showed that the method of tissue isolation could retain preferably the genetic characteristic of the crossbreeding strains. The similarity coefficients of the F2 generation ranged from 0.5250 to 0.9000 which showed that monosporous strains have more significant genetic variation in DNA level and rich genetic diversity. The results of fruiting test showed that the yield of five stains exceeded the yield of AG97, and the fruiting body of them have no obvious difference in the morphology. These preliminary results show that we can choose the excellent new strains from the single spore strains of the F2 generation。In this research, ten strains of F3 generation were selected from the monosporous strains of AG9710 which was the F2 generation. The genetic analysis of the F3 generation by ways of ISSR technique. The results showed that the similarity coefficients of the fourteen strains ranged from 0.5897 to 0.9231.It could be found that the difference among the ten strains of the F3 generation was large. Meanwhile, the genetic difference among F3 generation and AG97 and parent strains was increased。The experimental results indicated that, theISSR molecule marker not only revealed the genetic diversity and relationship of the strains of Agaricus bisporu, but also provided a criterion for preliminary selection and prediction of excellent hybrids, and provided a new idea of the way of the ISSR molecule marker guided conventional crossbreeding.