Screening Of Elite Inbred Lines And Combinations Of Cherry Tomato Against Late Blight And Yellow Leaf Curling Virus

Cherry tomato(Solanum lycopersicum var.cerasiforme),also known as Shengnv Guo in Chinese,is popular because of its rich nutritional value.Due to continuous cropping obstacles and unreasonable use of pesticides and fertilizers,tomato diseases are showing an increasingly serious overall trend in recent years.In this experiment,the field resistance identification and molecular marker technology were used to detect the cherry tomato material collected by the research group over 12 years.Studying the resistance of different materials to late blight and yellow leaf curl virus disease.Combining the agronomic traits of each material,screening excellent disease-resistant inbred lines as parents,preparing hybrid combinations,and conducting hybrid comparison experiments in spring.Through the investigation of botanical traits,fruit quality traits,field resistance and molecular marker detection of hybrid combinations,excellent hybrid combinations were screened.At the same time,the isolation and identification test of pathogens of late blight was carried out,in order to lay the foundation for breeding of new cherry tomato varieties with good resistance to late blight and yellow leaf curl virus and good economic performance.The specific test results are as follows:(1)In the spring screening,17 of the 33 materials showing resistance to late blight contained the Ph-3 gene,and 3 of them also contained the Ty-2 gene against yellow leaf disease.After repeated screening at autumn,a total of 12 high-generation inbred lines containing the Ph-3 homozygous gene against late blight were screened out,and 3 of them contained not only the homozygous gene of Ph-3 but also the homozygous gene of Ty-2.At the same time,32 Ty series gene inbred lines containing anti-yellowing leaf curl virus disease were screened,among which 19 homozygous material were obtained.Comprehensiving field traits survey,17 high-generation inbred lines were selected as parents to prepare hybrid combinations.(2)The cultivation test was carried out on 21 hybrid combinations which obtained in the previous year.Statistical results of botanical traits,fruit quality and resistance between the combined groups,screening out 6 better hybrid combinations.Among them,KZH-4 and KZH-15 not only has good taste,high yield,good economic traits,but also contains the Ph-3 gene resistant to late blight and the Ty-2 gene against yellowing leaf curl virus.(3)Collecting suspected tomato late blight strains in the field were isolated and identified twice,and carried out twice indoor isolation and identification.An effective separation method was summarized and eight strains were obtained,including Stemphylium lycopersici,Mucor circinelloides,etc.