Evaluation Of Germplasm Resources And Cultivation Techniques Of Stropharia Rugosoannulata

Stropharia rugosoannulata is a kind of edible mushroom popular in world market in recent years,because of its low fat and high protein concentration,which is in line with people’s pursuit of health food.With the increase of market demand,large-scale and industrial cultivation of the tasty mushroom developed rapidly,starving for effective cultivation technology and culture strains with steady and good qualities.At present,the quality of S.rugosoannulata strains is uneven,and the uniform standard of cultivation technology hasn’t been established.Cultivation materials,cultivation patterns,cultivation time and management methods vary from region to region,and the pests and diseases that exist during cultivation are not clearly defined,resulting in unstable yields.This study collected and scientifically evaluated the germplasm resources of S.rugosoannulata,screened excellent strains according to the specific environmental conditions of Hanzhong region,and optimized the preparation conditions of the preferred strains,focusing on cultivation raw materials,cultivation patterns,cultivation periods,soil covering materials,diseases and pests during the cultivation period,and summarized the key cultivation techniques of S.rugosoannulata in Hanzhong region.The main results of this study are as follows:1.Comprehensive evaluation and screening of germplasm:in this experiment,a comprehensive evaluation of the 20 collected strains of S.rugosoannulata was carried out,and it was found that strains with farther genetic distances could be distinguished by the somatic incompatibility method,while similar strains could not be accurately distinguished;using the ISSR molecular marker method,12 suitable primers were screened from 18 pairs of ISSR primers,and a total of 93 bands were amplified,with a polymorphism ratio with 77.4%.The genetic similarity level was between 0.68 and 1.00.At the genetic similarity level of 0.84,the strains could be divided into six groups,strain S7 alone belongs to group I,S1 and S5 group II,DA and H5 group III,S2,S4and D2 group IV,H1,H2 and H6 group V,and the other 9 strains are in group VI,among which the genetic similarity coefficients of strains D5 and H4 in groupⅥreached 1.The strains were judged to be determined as the same strain when combined with the antagonistic results.Therefore,the germplasm resources of 20 strains of S.rugosoannulata can be effectively evaluated by using traditional methods and ISSR molecular markers.Furthermore,the agronomic characters of the tested strains are different.The cap diameter is between 3.20～6.53 cm,the stipe diameter is 2.07～4.82cm,and the stipe length is 4.27～10.56 cm.The yield of strain H1 is high（1100 g/box）,but the mushroom type is relatively poor,so it can be used as the breeding material of high-yield strains.The agronomic character index and yield of strain D3 were better.In this experiment,strain D3 was selected as an excellent strain to be further studied in the cultivation technology.2.Optimization of strain preparation conditions:through single factor,Plackett Burman experiment and response surface central design method,the optimal medium formula of liquid strain of S.rugosoannulata was determined as follows:glucose 30.30g/L,yeast extract 3.74 g/L,Peptone 1.00 g/L,KH₂PO₄2.00 g/L,Mg SO₄·7H₂O 1.00 g/L and Vitamin B₁19.00 mg/L.By adding different amounts of soil to the formula to prepare the original and cultivated species,it was concluded that the average mycelial growth rate of the original formula with 2%field soil could reach 4.94 mm/d,and the mycelial growth was good;The best formula Z-2 was selected as follows:65%corn straw,15%corncob,11%sawdust,5%rice husk,2%field soil,1%lime and 1%gypsum.3.Study on supporting cultivation techniques:the effects of different cultivation substrates,cultivation modes,cultivation time,soil covering materials on mycelial growth,yield and agronomic characters of S.rugosoannulata were studied.The optimum culture medium of S.rugosoannulata was 70%corn straw and 30%sawdust;The suitable cultivation mode and cultivation time were border cultivation and mid October respectively;When the ratio of field soil to peat soil is 1:1,it is the most appropriate covering material,under this condition,the output can reach:2295.70 g/m~2.4.Investigation and research on diseases and insect pests:the occurrence of diseases and insect pests in the cultivation of S.rugosoannulata was investigated and studied.It was found that diseases and pests of S.rugosoannulata occurred from time to time,among which fungal competitive diseases could occur in spring and autumn;Pests also occur in the two seasons.The main pests such as mushroom gall and springworm are accompanied by the occurrence of miscellaneous bacteria.The occurrence of bacterial diseases of S.rugosoannulata planted in spring is the most serious,with an incidence of 4～5%.The disease type is bacterial soft rot.The soft rot sample was studied and 14 strains of bacteria were isolated.The back connection experiment verified that strain Sr-7 had the strongest pathogenicity.It was identified that the pathogenic strain Sr-7 was a species of Pantoea sp.,which was found on the fruiting body of S.rugosoannulata for the first time.Through this study,the germplasm resources of S.rugosoannulata in Hanzhong region were clarified,which not only provided scientific reference for the large-scale cultivation of S.rugosoannulata,but also provided theoretical support for the comprehensive utilization of agricultural waste.