| Lentinula edodes is a a edible snd medicinal fungi, it’s also a strong competitiveness industry in our agricultural structure,but the phenomenon “the same species with different name,different species with same name” is very common, so determine the relationship between different Lentinula edodes strains, establishing germplasm repository, having important theoretical guiding significance. The study collected 35 main cultivated varieties from southern shaanxi,including Hanzhong, Ankang, Shangluo, etal, by analysising of selected strains’ mycelium growth rate,observe the colony morphology, ITS sequencing analysis, Construction of homology comparison and homologous tree, the calculation of genetic distance, and the construction of a phylogenetic tree based on ITS sequence. Investigation and research of main cultivated varieties of Lentinula edodes in germplasm resources, the biological characteristics,and determine the relationships between different strains; Research the optimization of polysaccharide extraction process, polysaccharide extraction rate as the response, value to liquid ratio, microwave power and microwave time for single factor, using Box- Behnken response surface design method set up mathematical model, looking for the best extraction process. The results of the study are as follows:1. The biological characteristicsUsing slab method to study the biological characteristics of main cultivated varieties with Lentinula edodes, measurement analysis their mycelium growth rate, surveying mycelium morphology, color, density of observation records. The results showed that 35 strains were edodes strains colony morphology in villous, in mushroom strains differences between individuals, edge growth appears neat or not neat, some edges with the fuzzy phenomenon; 2011-8, 2019-9, H8, 908, CG, NS1#, WX1# grow fastest, and 808-1, 9608, 507, medium speed, SL15# and QK20, 241-6, L-241, 2796,are the slowest,35 strains’ average growth rate is 5.29 mm/d. After LSD significant difference analysis, H8, 908, CG and NS1# significantly larger than other strains differences. Study the biological characteristics wihn the agronomy characters, mycelium growth rate, and colonial morphology. For establishing the germplasm bank offers a preliminary theroretical fundation.2. ITS sequencing analysisFor study their genetic relationship, 35 Lentinula edodes strains total DNA extracted with the use of CTAB method, application of fungal universal primers ITS1 and ITS4 PCR amplification, for different strain amplification product sequencing analysis, based on the results of ITS sequence, comparison homology, the construction of the homology tree, genetic distance analysis, and based on the evolutionary tree ITS sequence analysis to construct system, determine the genetic relationship between strains. The results show that the QK20, SL8-1, SL8#, 05, HN3#, Q12, 939, 241-6, 908, 2011-8 and 2019-9 together on a branch, they have a near relationship; H8, 2796, WX1#, CG, SX10# together on a branch, had a near relationship, 808-1, TX, 808, SL15# and XG, LY8#, XL8# together on a branch, had a near relationship; L-241, QX9#, D2, HN1#, Z1, 135, 9608, 9008 together on a branch, they have a close relationship; XGRD, 507 and NS1# together on a branch, they have a near relationship; For studying the genetic diversity and germplasm bank offers an important theroretical basis.3. The study of polysaccharide extraction technologyThe microwave-assisted extraction technique for polysaccharide from Lentinus edodes was optimized to provide theoretical basis for the industrial production and comprehensive utilization of polysaccharide from Lentinus edodes. The Box-Behnken response surface method(RSM)based on mathematical modle was established using polysaccharides extraction rate as response value, and using the ratio of liquid to solid(m L/g)(15?1, 20?1, 25 ?1, 30?1, 35?1), microwave power(500, 600, 700, 800, 900 W) and microwave time(2, 4, 6, 8, 10 min) as factors to screen optimum extraction conditions for polysaccharide from Lentinus edodes. To optimun conditions obtained by RSM were: ratio of liquid to solid(m L/g) 35:1, microwave power 900 W, microwave time 8.5 min. On these conditions, the extraction yield of polysaccharide is up to 6.49%, while the experimental extraction rate was 6.72%, with a difference of less than 5%. Optimization of the polysaccharide from Lentinus edodes with microwave-assisted by Box-Behnken RSM was convenient and feasible. |
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