Establishment Of ’Yuexiu’ Strawberry Tissue Culture Rapid Propagation System And Study On Three Main Virus Eradicate Techniques

Strawberries are highly popular in the fresh fruit market,due to the high benefits of strawberry cultivation,a large number of introduced and cultivated strawberries have been developed into a characteristic industry in many places in recent years.However,strawberry virus disease has also become increasingly serious,leading to a significant decline in the yield and quality of strawberries.Planting non-toxic seedlings is an effective way to fundamentally prevent the spread of viral diseases,but there are still important problems such as high demand and insufficient supply of emerging varieties of high-quality seedlings in the market.Therefore,cultivating non-toxic strawberry seedlings and establishing rapid propagation system are crucial for the sustainable development of strawberry industry.In this study,using’Yuexiu’strawberry stolons as experimental materials,and the optimal combination of disinfection time for explants was screened.Using tissue culture technology and orthogonal test method,the relevant factors affecting the rapid propagation of strawberry were investigated,and the optimal hormone ratio of the culture medium was selected.RT-PCR virus detection was conducted on’Yuexiu’strawberry tissue culture seedlings to determine the type of virus carried.Through stem tip culture and heat treatment combined with stem tip culture,effectively eradicate three common viruses:SMo V、SVBV、SMYEV,and conducted heat tolerance test on tissue culture seedlings of 8 non-toxic strawberry varieties.The main research results are as follows:The optimal sterilization method for establishing’Yuexiu’strawberry explants was75%alcohol treatment for 40 seconds,0.1%Hg Cl₂ treatment for 3 minutes,and the survival rate was 90.0%;The optimal medium for stolon induction is MS+1.0 mg/L 6-BA+0.3 mg/L IBA+0.3 mg/L NAA,with an induction rate of 100%.The influence of three hormones on stolon induction is 6-BA>IBA>NAA;The optimal medium for adventitious bud proliferation was MS+0.5 mg/L 6-BA+0.05 mg/L IBA+0.15 mg/L GA₃,with a proliferation coefficient of 7.53.The influence of three hormones on adventitious bud proliferation was 6-BA>IBA>GA₃;The optimal medium for rooting culture is 1/2MS+0.2 mg/L IBA.At this time,the average number of roots per strawberry plant is 18.77,and the average root length is 3.63 cm.Three common viruses,SMo V,SVBV and SMYEV,were detected by RT-PCR on the successfully established’Yuexiu’strawberry tissue culture seedlings.The detection rates were 79.7%,49.2%and 21.1%,respectively.The virus compound infection rate was 46.1%,and most of the SMo V and SVBV were compound infections.0.5mm or1mm stem tip in vitro culture of’Yuexiu’strawberry tissue culture seedlings cannot remove any virus;After culturing the regenerated seedlings,the same size stem tips were taken,and the removal rates of SMo V,SVBV,and SMYEV were 33.3%,20.0%,and 30.0%after secondary cultivation of 0.5 mm stem tips.After subculture for 14 days,the’Yuexiu’strawberry tissue culture seedlings with a plant height of about 3 cm were subjected to heat treatment at 36℃for 16 hours and 32℃for 8 hours.After heat treatment for 35 days,the survival rate was 93.3%.After stripping 0.5 mm of stem tips and culturing,the regeneration rate was 80.0%.Under this condition,most of the viruses could be eradicated.The virus-free rates of SMo V,SVBV and SMYEV were respectively 70.0%,100%and 80.0%.The growth of strawberry tissue cultured seedlings of different varieties was slowed down under 36℃illumination for 16 hours,32℃darkness for 8 hours,and heat treatment for 35 days.However,the leaf death rate and survival rate were different,among which the survival rates of’Yanli’,’Xingxiang’and’Yuexiu’were the highest after heat treatment for 35 days,all of which were 93.3%.The survival rates of’Zhangji’,’Christmas Red’and’Ningyu’are slightly lower compared to each other,with 86.7%,83.3%and 80%,respectively.The survival rates of’Miaoxiang No.3’,’Sweet Charlie’and’Snow White’were only 73.3%,70.0%and 66.7%,respectively.In addition,the leaf death rate of’Snow White’and’Sweet Charlie’is as high as 40%.This study established a tissue culture rapid propagation system of’Yuexiu’strawberry,optimized the conditions for eradicating SMo V,SVBV,and SMYEV under variable temperature heat treatment,and clarified the heat resistance of common strawberry varieties,providing a theoretical basis for cultivating high-quality virus-free strawberry seedlings.