Breed New Strains Of Pleurotus Cornucopiae And Agaricus Bisporus By The Technique Of Single Spore Crossbreeding

The objectives of this study were to breed new excellent strains of Pleurotus cornucopiae and Agaricus bisporus by the technique of single spore crossbreedingThe parent strains of Agaricus bisporus were the Ag56 with high yield but low quality and Zl with high quality but low yield. Twenty-six homokaryon strains were obtained which were mated 160 combinations. Sixteen hybrid strains were obtained from these combinations. Then two excellent hybrid strains were selected through cultivating in the laboratory and field conditions. The esterase isozyme electrophoresis patterns and the dendrogram based on the AFLP fingerprints showed that there were some genetic differences between the hybrid strains and the parent strains, the two hybrid strains were similar. So the hybrid Ag25623 strain was selected to demonstrate in the different field conditions, and was proved to be a high yield and high quality strain of Agaricus bisporus. The fruit body of the Ag25623 strain was white and compact. Its pileus was smooth and circular. Its stipe was short and thick.. The yield was increased by 18% compared with the As2796 which is a main Agaricus bisporus cultivar presently in Sichuan Province.The XD33 strain(a main Pleurotus cornucopiae cultivar in Province Sichuan) was crossed with the P235, QS9111, ZY1, CB1 and C5 strains of Pleurotus ostreatus (all of these Pleurotus ostreatus strains were high yield or could endure high temperature) and M31 strain(a Pleurotus cornucopiae strain). One hundred and fifty-two monokaryon strains were obtained which were mated the 471 combinations. Three hundred and thirty combinations were compatible. Through cultivating in jars and bags and selected successively and the variety comparing experiment, the excellent hybrid JQ1810, JQ1910, JH2525 and JM334 strains were obtained. The esterase isozyme electrophoresis patterns showed that the hybrid JQ1810 and JM334 had new enzyme stripes which didn't appear in parent strains. The dendrogram based on the AFLP fingerprints indicated that there were great genetic differences between JQ1810 strain and its parent strains, but the genetics of the hybrid JH2525 strain and its parent P235 strain was very similar. The excellent hybrid JQ1810 strain and JM334 strain were demonstrated in the different field conditions, and was proved to be two high yield and high quality strains of Pleurotus cornucopiae. The fruit body of the JQ1810 strain was gray. The pileus was small and circular. The stipe waslong and thin. The number of fruit body was much and the size was uniform. The yield was increased by 23% compared with the XD33 strain. The fruit body of the JM334 strain was deep gray. The pileus was thick, big and circular. The stipe was short. The number of fruit body was much and the size was uniform. The yield was increased by 19% compared with the XD33 strain.The tissue isolation strains from different growth periods and different parts of the Pleurotus cornucopiae hybrid JQ1910 strain and its spores isolation strain compared with parental strain in the antagonism, the growth rate of mycelia, the esterase isozyme electrophoresis patterns, the yield and the form characteristics of fruit body. The objective of the study was to discuss the method of genetic characteristic retainment of Pleurotus cornucopiae hybrid strain. As a conclusion, the method of tissue isolation could retain preferably the genetic characteristic of Pleurotus cornucopiae hybrid strain, The strain isolated from spores would alter the genetic characteristic of the hybrid strain, and high yield strain could be hoped to get from the coral-like period of fruit body and the gill tissue of little fruit body.