Studies On The Cross Breeding Of Flammulina Velutipes And Strain Breeding Of Wild Mushroom

In this thesis, the economical and hereditary characters and genetic relationship among 22 Flammulina velutipes strains were firstly analyzed by some methods, including fruiting test, esterase isoenzyme and RAPD techniques in order to screen out the parents for cross breeding. And then, the cross breeding was carried out by using monosporous hybridization technique. Finally, the optimum culture mediums for 6 types of wild mushrooms were investigated. The results were as follows:1. Twenty two Flammulina velutipes strains were raised on PDA culture medium and the result showed that the strains of NO.3, NO.2, NO.4 and NO.7 had better preferable growth velocity, which was 3.56 mm/d, 3.18 mm/d, 3.18 mm/d and 3.08 mm/d, respectively. The strains of NO.12 and NO.13 had slower growth velocity, which was 2.35 mm/d and 2.11 mm/d, respectively. The characteristic of colonial morphology of NO.7(Bj-3), NO.16(san ming B), and NO.19(F39) was regular, and their mycelia were pure white and hairchested. The result of the fruiting test indicated that NO.7 and NO.9 strains, which were named as Bj-3 and F39, had the highest biological efficiency in the first mushroom flush, whose efficiencies were 73.70% and 71.48% respectively, and there was no significant differences between them, therefore they are suitable as factory bacteria of Flammulina velutipes. The lowest biological efficiency of NO.19 named as F39 was only 36.35%. The strain who had the shortest riperning time of fruiting body was NO.1(2102), which was 20.1 d; the rest strains, which were ranked in order of riperning time from high value to low, were NO. 4(2102), NO.18 (1301) and NO.2(huang 1), whose value were 20.1d, 20.2 d, and 20.7 d, respectively. The longest one is NO.10(HE-1), whose ripening time was 42.7d.2. The esterase isozyme and RAPD technique were employed to investigate the relationship among the 22 strains, and the results revealed that the similarity coefficient between NO.7 and NO.8(ri jin 1), 9(san ming C), 10(HE-1) was 0.1, showing that the relationship between NO.7 and NO.8, 9, 10 was remote. The test results suggested that the genetic relationship among NO.1(2012), NO.2(huang 1), and NO.7(Bj-3) was close and NO.8, NO.9, and NO.10 had close genetic relationship. The similarity coefficient between NO.5(su 6) and NO.20(xin su 6) was 1.0, which suggested that the two strains were probably the same species with different names. The genetic relationship between NO.1(2012), NO.2(huang 1), NO.7(Bj-3) and NO.8, NO.9, NO.10 was remote.Through comprehensive analysis of the biological characteristics and genetic relationships of all strains, we found that NO.7(Bj-3) was better in growth velocity, ripening time and the biological efficiency of first mushroom flush, but had lower ratio of cover to stalk and weak biological characteristics of fruitbody. While the ratio of cover to stalk and characteristics of fruitbody of NO.10 were prior to NO.7. The similarity coefficient between Bj-3 and HE-1 was only 0.1, indicating that the relationship between the two strains was remote. Therefore, NO.7 and NO.10 were selected as parents for hybridization to screen white or yellow strains with heterosis.3. Taken fruiting body spores of NO.7(Bj-3) and NO.10(HE-1) strains as material, 75 strains were produced through monospore hybridization. Their hypha growth velocity, colony morphological characteristics, ripening time, biological efficiency of first mushroom flush, morphological characteristics of fruiting body and esterase isozymes profile were further investigated. Results showed mycelia of NO.13, NO.24 and NO.57 had the faster growth velocity; NO. 1, 2, 5, 9, 10, 11、13、15、16、17、20、21、22、25、29、30、33、34、37、40、41、42、45、47、48、52、55、56、57、59、62、64、66、67、69、70、71 and 73 had even colonial periphery and hairchested and compact hypha. NO.12, 28, 44 and 57 strains had shorter ripening time; NO.5, 8, 27 and 57 were higher on the biological efficiency of first mushroom flush; NO. 4、13、16、17、42 and 57 had fruiting bodies with good commodity characteristics. Based on the comprehensive analysis above, NO.13, 16, 57, 66, 73 were determined to be superior strains. The analysis of esterase isozyme zymograms of 5 hybrid strains showed that they had preferable genetic relationship.4. The optimum mother culture medium, second culture medium and conditions for 6 wild edible mushrooms collected in Hebei Province were determined by screening the compositions of culture medium, pH and temperature. The optimum mother medium for Calocybe gambosa and Lyophyllum decastes was enriched PDA medium; the optimum mother medium for Agaricus comtulus was onion, soy and agar medium; the optimum mother medium for Clitocybe maxima and Leucopaxillus candidus was wheat extractive medium; the optimum mother medium for Clitopilus prunulus was sawdust extractive medium.The optimum second medium for Calocybe gambosa and Agaricus comtulus was cottonseed hull and bran medium; The optimum second medium for Lyophyllum decastes and Clitopilus prunulus was sawdust and bran medium; The optimum second medium for Clitocybe maxima and Leucopaxillus candidus was wheat and sawdust medium.The limits of optimum temperature for 6 types of wild mushroom was from 24 to 26℃, and the optimum pH arrangement was from 5.5 to 6.5, meanning that they are more suitable in acid environment. Our research established the foundation for artificial domestication of wild mushrooms.