| Tomato is widely accepted as a nutrient-rich crop.Soluble sugar content is one of the most important indicators that affect tomato flavor.In the experiment,three representative types of tomatoes were selected to study,namely Solanum lycopersicon var.esculentum,Solanum pimpinellifolium and Lycopersicon esculentum var.cerasiforme.The difference between the soluble sugar content of different varieties of tomato was determined.The protein sequence of sucrose invertase inhibitor was obtained by genetic engineering technology.The difference of the protein sequence obtained from the experiment and the tomato gene bank was analyzed.Finally,the relationship between the natural variation of the sucrose invertase inhibitor and the sugar content of the tomatoes was studied.The main conclusions are as follows:1.The soluble sugar content in tomato juice of nine tomato species was detected by chemical methods.The total sugar content of Solanum lycopersicon var.esculentum Alisa,T20-008 and T29-023 were 39.35±0.44,36.69±1.28,36.76±0.81 mg/m L,respectively.The total sugar content of Solanum pimpinellifolium 407534,110595 and LA1589 were32.69±0.64,29.73±1.34,31.25±0.97 mg/m L,respectively.The total sugar content of Lycopersicon esculentum var.cerasiforme 114967,387855,and 183560 were 42.65±2.74,40.4±0.74,45.15±1.74 mg/m L,respectively.Lycopersicon esculentum var.cerasiforme have the highest sugar content.2.Extract the cell wall sucrose invertase inhibitory protein(INH1)and vacuolar sucrase inhibitory protein(INH2)DNA of nine test tomatoes and amplify them by PCR technology.Phyre2 was used to model each inhibitor protein,QMEAN and Pro SA were used to evaluate the quality of the modeling,and each model was in the confidence interval.3.Compared with cultivated tomatoes and Solanum pimpinellifolium,it was found that INH1 of Pannali tomato had deletions at positions 1-8,mutations at positions 69 and 149,and INH2 had mutations at positions 30,54,104 and 161.These deletions and mutations may have a positive effect on the sugar content of tomatoes.4.Combining with the sugar content,comparing the sucrose invertase inhibitor protein sequences of nine test tomatoes.It is found that there are fewer mutations in INH1,and the difference in sugar content between the same types of test tomatoes is more related to the natural variation of INH2.The protein sequences of the nine-test tomato INH2 are the same at positions 21-155,indicating that the probability of natural mutations at these positions is low.The deletion of positions 15-17 in INH2 has a positive effect on tomato sugar content.When the 162-171 position sequence is VRNLL,it has a negative effect on tomato sugar content. |
