Selection Of Inbred Lines Asisted With Molecular Markers And Hybrids In Cherry Tomato

Cherry tomato is one of the many members of the tomato family and popular with consumers as a kind of fruits of vegetables.In recent years,the consumption and planting area of cherry tomato continue to increase,it has strong disease resistance and significant benefits,and occupies an increasing proportion in the development of agricultural economy.So cherry tomato will have a good prospects.But in general,the study of genetic breeding and new cultivars about cherry tomato in China started late compared to the big fruit tomato,we have achieved initial results in new cultivars,but it is necessary for us to further study and explore germplasm resources,it will be highly significant for enriching the variety of cherry tomato and improving the ability of independent innovation of seed industry and promoting the development of industrialization.In this study,we combined conventional breeding and marker-assisted selection,investigated agronomic traits,separated inducted parting material and screened out excellent inbred lines;In the meantime,we created cherry tomato inbred lines with enhanced cold tolerance through the backcrossing;Then we used good inbred lines as parents to create cross combinations,then carried out comparison test to breed new cross combinations with high yield,high quality,and more resistance,to create new cultivars.On this basis,we analyzed the characteristics of various traits of cross combinations and their parental materials,it provided information for future matching of cherry tomato hybrid parents.The main test results are as follows:1.Breeding of inbred lines:Investigated the agronomic traits about botany, inflorescence,fruit et al of 145 cherry tomato materials,combined with 16 molecular markers such as Ty-1,Ty-2,Ty-3,Ph-3,Mi-1,Tm-2^a,I-2,Cf-5,Cf-9,Frl,Asc,Pcc, Pto,Og^c,hp,gf,screened out 33 inbred lines with Ty-1 gene,59 inbred lines with Ty-2 gene,7 inbred lines with Ty-3 gene,93 inbred lines with Ph-3 gene,30 inbred lines with Mi-1 gene,97inbred lines with Tm-2^agene,37 inbred lines with Cf-9 gene, 41 inbred lines with I-2 gene,82 inbred lines with Frl gene,39 inbred lines with Asc gene,70 inbred lines with Pcc gene,32 inbred lines with Pto gene,4 inbred lines with Og^cgene,1 inbred lines with hp-1 gene,4 inbred lines with gf gene,1 inbred lines with Cf-5 gene.There are 64 inbred lines with above 5 disease resistance genes. And we have screened out five excellent inbred lines that can be used as backbone parents.2.Back crossing of cold-tolerant material:Back crossing of cold-tolerant material has completed in 10 excellent inbred lines of two rounds of back cross pollination and investigation of agronomic traits,we have obtained the seeds of BC₂in the autumn of 2016.The identification test of cold tolerance at seedling stage showed that F₁with cold tolerance gene had higher resistance on cold tolerance than that of recurrent parent.3.Breeding of cross combinations:Compared 128 cross combinations in spring and autumn in 2016.We obtained 8 excellent cross combinations such as HY8,HY9, HY42,ZY19,ZY38,ZY41,PY15 and XY1,they are expected to enter the next multi-point test.