Preliminary Study On The Selection Of Crossing Parents And The Breeding Of Excellent Hybrid Strains In Lentinula Edodes(Berk.) Pegler

Variety comparison test were done in 26 Lentinula edodes cultivation strains, 10 protoplast hybrid strains and 4 wild strains. A method of grey correlation degree analysis was applicated to analysis 8 agronomic characters such as pileus diameter, pileus thinkness, stipe length, stipe diameter, average fresh weight of a single fruitbody, average fresh yield of fruit body per bag, average numbers of fruitbody per bag and fruiting period. Five excellent strains were seselcted from 40 strains tested in three pairs of cross combination, antagonistic test and compaired the agronomic characteristics. Isolation single spores, selected monocytes mycelium and then mating. We got 55 excelent hybrid strains which can grow well on PDA media. The cultivation test results revealed that 3 hybrid strains can not be growth in the sawdust medium, 9 hybrid strains growth slow or sparse in cultivation bag, 4 hybrid strains not change color or can not producing mushroom after color-changed in cultivation bag, 20 hybrid strains only grow few or diformed fruitbodys and only 19 hybrid strains fruiting normal. Use of grey correlation analysis, selection of the comprehensive characters better strains Q6-12, W-2, W-13, QK-8, QK-15 entered in the middle test from 19 normal fruiting of hybrid strains.ISSR marker was applied for study on genetic analysis of cross combination Qiu 6×K95-1 and their hybrid strains. 33 ISSR primers were screened and 10 of which could differentiate hybrid strains effectively were selected to amplify the 23 L.edodes strains. A total of one hundred and twenty-eight fragments were amplified, among which one hundred and twenty fragments(93.8%) were polymorphic. According to amplification results, genetic similarity coefficient matrix among thirty-six strains ranged from 0.25 for the lowest similarity co-efficient to 0.83 for the greatest extent of similarity. All the tested strains were clusted into 2 groups at 0.46 similarity level. The strains in the first group all produced fruit except QK-17, amplification products also supported the agronomic characters. QK-5 and QK-20 have the same fruit body quality and average fresh weight of a single fruitbody, they could be classified into the first group at 0.87 similarity level. QK-18 and QK-19 have few fruitbody, so have low yield. QK-7, QK-8 and QK-16 have same fruit body quality, average numbers and fresh weight of a single fruitbody per bag with their parent K95-1 which was clusted into one group at 0.80 similarity level. QK-15 have the same pileus shape with parent K95-1, and have higher yield and longer stip then its parents, but it was clusted into one group at 0.86 similarity level with QK-18 and QK-19. The second group have four strains which had no fruit body. ISSR marker is a powerful tool in screening excellen hybrid strains of L.edodes strains, thus greatly reducing crossbreeding in the screening workload.