Screening Of Guangxi’s Disease-Resistant Tomato Germplasm Resources And Preparation Of High-Quality Hybrid Combinations

Tomato industry in Guangxi is mainly dominated by introduction,but whether it is wild or cultivated species,there is genetic variation in tomato’s response to the environment,which may result in the loss of disease resistance genes or the decline of fruit quality due to climate,soil environment and other reasons.Therefore,the selection of tomato varieties suitable for the promotion and cultivation in Guangxi has practical significance of accelerating the development of agricultural industrialization and improving the income level of farmers.In this experiment,on the one hand,the resistance genes of some high generation tomato inbred lines were detected by molecular marker technology,and the botanical characters of the excellent inbred lines were investigated,which laid the foundation for tomato breeding in Guangxi.On the other hand,the hybrid combination of polymeric resistance genes and excellent quality was prepared to provide valuable materials for the development of tomato industry in Guangxi.1.Identification of disease resistance and fruit traits of high generation inbred lines:the third-generation molecular marker technology KASP was used to conduct disease resistance gene detection test research,and the ability of inbred lines to resist disease was analyzed and evaluated by cluster analysis.The results showed that,out of 90 inbred materials,there were 9 materials with strong disease resistance,namely FG4,FG19,FG25,FG28,FG36,FG49,FG75,FG77,FG86,of which FG19,FG49,FG75 were large tomatoes,the rest were cherry tomatoes.There were 4 materials with disease resistance and 76 materials with low disease resistance.Among the 10 inbred line materials,FG4 and FG75were of finite growth type,while the others were of infinite growth type.The fruit shape index is between 0.75 and 1.53.The single fruit weight of cherry tomato inbred line was between 13.53 g～21.86 g,while the single fruit weight of big tomato inbred line was between 156.83 g～183.52 g.The fruit hardness ranged from 0.42 kg·cm^-2to 0.81 kg·cm^-2.The sugar content is between 4.5%and 8.0%.2.Selection and quality testing of hybrid combinations:The hybrid combinations were prepared in the autumn of 2018 and the field growth data of the four hybrid combinations were investigated in the spring of 2019.Disease resistance gene test and fruit quality comparison test were conducted.The results showed that all the 4 hybrid combinations contained late blight resistance gene ph-3,LC1,LC3 and LC4 materials contained anti-yellowing leaf curl virus genes Ty-1,Ty-2 and Ty-3,and LC2 materials only contained anti-yellowing leaf curl virus genes Ty-1 and Ty-3.LC1 material plants had a strong growth potential and a large number of flowers during the growth period.The single fruit is heavier,the content of phosphorus,potassium,sodium and calcium in the fruit is higher,the antioxidant capacity is stronger,and the shelf life is about 27 days.LC2 was pink fruit with high sugar content and moderate sugar-acid ratio.It has a good taste,low nitrogen content in the fruit,and a beautiful heart-shaped vertical section.The LC3 plant had large stem,good growth and was not prone to lodging.The fruit had a high sugar content and a sweet taste.The content of ascorbic acid,lycopene,sodium,magnesium and calcium is high in the fruit.LC4 is a late-ripening material with high fruit hardness,high content of lycopene,calcium and soluble protein.It has strong metabolic activity and is resistant to storage and transportation.The hybrid combination with the highest comprehensive quality was LC2,followed by LC3,LC1 and LC4.