| Strawberries are known as the "queen of fruits" and have high economic value.In recent years,the cultivation area of strawberry in China has been increasing,but the spread of strawberry virus disease has caused strawberry variety degradation and a significant reduction in production.Therefore,it is of great significance to analyze the virus-carrying status of existing strawberry germplasm resources and establishing a virus detection and efficient breeding system for strawberry seedlings to support the healthy development of strawberry industry.In this study,86 strawberry resources were used as materials.We analyzed the impact of virus infection on traits such as flowering,creeping stem,fruit yield,and single fruit weight of strawberries.we clarified the virus-carrying situation of 86 strawberry samples,established the detection methods for three kinds of virus diseases,the efficiency of shoot tip virus free from different strawberry resources was compared and studied the effects of factors such as seedling age,plant growth regulators,and matrix formulations on strawberry rooting.The main results of this study are as follows:1.Among the 86 strawberry samples analyzed,28 samples tested positive for viruses,with a virus infection rate of 32.56%.The detected virus included Strawberry vein banding virus(SVBV),Strawberry mottle virus(SMo V)and Strawberry pallidiase-associated virus(SPa V);Among them,11 samples were infected with SMo V(12.8%);23 samples were infected with SVBV(26.7%)and 5 samples were infected with SPa V(5.8%).18 samples were infected with single virus and 10 samples were infected with multiple viruses.7 samples carried both SVBV and SMo V,2 samples carried both SVBV and SPa V,and one sample carried all three viruses(SVBV,SMo V and SPa V)at the same time.2.The analysis results of the effects of virus infection on the growth of strawberry plants in the field showed that the fruit yield and plant growth morphology of infected plants were different from those of uninfected plants.In terms of yield,the malformed fruit rate of infected plants was significantly higher than that of uninfected plants in the same variety,and the average single yield per plant and fruit weight per plant were significantly lower than that of uninfected plants.In terms of plant growth morphology,the indexes of infected plants were significantly lower than those of uninfected plants in the same variety.3.The results of high temperature(treatment at 40℃ for 7 d)combined with stem tip culture showed that the survival rate of different varieties of stem tips was different.The survival rate of Tudela was the highest,reaching 80%.The survival rate of Xiaobai,Tokun(SMo V),Benihoppe and Riva were 0,followed by Tenira with 20%.The overall survival rate was 36.60%.The virus-free rate of strawberry plants infected with different viruses was also different.There were 3 strawberry varieties infected with SPa V,and 10 out of the 12 inoculated explants were successfully detoxified,with a detoxification rate of 83.33%.There were 8 strawberry varieties infected with SMo V,and 21 out of 26 inoculated explants were successfully detoxified,with a detoxification rate of 80.77%.Among the 13 strawberry varieties infected with SVBV,and 19 out of 58 inoculated explants were successfully detoxified,with a detoxification rate of 32.76%.The overall detoxification rate was 42.68%.4.During the process of propagating virus-free seedlings of the ‘Benihoppe’strawberry variety by cuttings,the root growth of seedlings 40-50 day was better than that of younger seedlings 20-30 day.The concentration of IBA used for rooting had a significant effect on the rooting of lateral stem cuttings,and the best result was achieved with 6mg/L IBA soaking the stem cuttings.The deeper the hole in the planting tray,the longer the root grows,and the more roots there would be.G2 formula(peat(5-20):perlite =3:1)and G6 formula(coconut bran: vermiculite =3:1)were found to be suitable substrates for virus-free "Benihoppe" strawberry seedling propagation by cuttings.In conclusion,by comparing the virus-free and virus-free seedlings of the same varieties,the virus had significant effects on the growth morphology and fruit yield of strawberry plants.this study established a detection system for SVBV,SMo V and SPa V and analyzed the virus-carrying status of 86 strawberry samples.The method of high temperature combined with stem tip culture was used for virus elimination.The results showed that SPa V was the easiest to remove,followed by SMo V,and SVBV was the most difficult to remove.The cutting test results of stolon seedlings showed that: it was found that seedlings 40-50 days,6mg/L IBA rooting concentration,32-hole planting tray with a depth of 110 mm and the formula matrix(peat(5-20): perlite =3:1)were the most effective for rooting.This study provides theoretical and technical basis for virus detection,efficient breeding of virus-free strawberry seedlings and development of virus-free culture. |
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