Preliminary Mapping Of Tomato Chlorotic Virus Resistance Gene TC11.1 And Creation Of Resistant Germplasm

Tomato is one of the most widely cultivated vegetable crops in the world.Tomato chlorosis virus?ToCV?is an epidemic disease in recent years,which causes huge economic losses to tomato industry.At present,there are few researches on Tomato chlorosis virus,especially on the genetic location of tomato resistance genes,the development of molecular markers and the breeding of resistant varieties.Therefore,it is of great significance to identify and clone the genes of tomato chlorosis resistance,and it can accelerate the breeding process of ToCV resistance in China.In this study RT-PCR identification and virus particle observation of significance were carried out.Eleven tomato cultivars carrying different genes of resistance to TYLCV?Ty-1,Ty-2,Ty-3?were natural inoculated with Whitefly in the field.At the same time,the CP?coat protein?and HSP70?heat shock protein 70?gene of ToCV and TYLCV DNA-A were sequenced,and compared with the sequences of ToCV and TYLCV that have logged in NCBI,then the phylogenetic tree was constructed.In this study we are located the resistance to ToCV gene TC11.1 and created resistant materials that can be used for further genetic mapping.The main results are as follows:1.The results of transmission electron microscopy showed that the organelle structure of susceptible leaves was not obvious,chloroplast and mitochondria disintegrated,and there were a large number of virus particle aggregates in tomato sieve cells.2.The HSP70 gene of ToCV has the highest homology with the isolate of Yangling,Shaanxi Province?mf346384?,up to 99.9%,and it is the same branch of phylogenetic tree with Shanxi Yangling,Shanxi Jinzhong.The CP gene of ToCV has 99.7%homology with the most of isolates,and it is the same branch of phylogenetic tree with domestic isolates.It is closely related to Jilin,South Korea and Spain.TYLCV's sequence has the closest relationship with the United States and Mexico,and the farthest relationship with Iran.The results showed that the tolerance of tomato varieties with different resistance genes?Ty-1,Ty-2 and Ty-3?to ToCV was different.Compared with those without resistance genes,the tolerance of tomato varieties with Ty-1,Ty-2 and Ty-3 genes to ToCV was better,but the tolerance of tomato varieties with Ty-1,Ty-3 or Ty-2 gene was slightly worse.3.With F₂ generation and F₃ generation of 142-1009×LA1028 as the main research materials,the resistance gene TC11.1 was located in the range of molecular marker HP2697-HP2713?about 730 KB?by genetic and phenotypic analysis.72 genes were detected in the localized region of TC11.1.In these genes,8 candidate genes were selected,respectively is:Solyc11g010700,Solyc11g010730,Solyc11g010860,Solyc11g010940,Solyc11g011020,Solyc11g011080,Solyc11g011090,Solyc11g011180.Created three new materials that can be used for mapping disease resistance gene.According to the results of this study,the cultivated tomato varieties carrying tomato yellow leaf curl resistance genes?Ty-1,Ty-2,Ty-3?at the same time have better tolerance to ToCV.The F₂ and F₃generation was used as research material to locate the Tomato chlorotic virus resistance gene TC11.1within the range of 730 kb,which laid the foundation for the positioning and cloning of tomato disease resistance genes.