Is one of the main founders in the field of international vegetable genomics. In 2007, the International Cucumber Genome Project was launched and implemented. It is the first time in the world to draw a plant genome sequence map by using the new generation DNA sequencing technology, complete the cucumber genome sequencing and biological analysis, reconstruct the chromosomal evolution path of cucurbitaceae crops, and discover cucurbitacin biosynthesis gene clusters, which is a major breakthrough in the basic research of horticulture in China. As the chief scientist of the China team of the International Potato Genome Sequencing Project, he led the China team to complete the haploid potato genome sequencing, realizing the leap from participation to dominance, and preliminarily clarifying the genome basis of self-pollination decline and potato tuber development, and was rated as one of the "Top Ten Scientific and Technological Progress in the World" by academicians of the two academies in 20 1 1 year. In addition, he also participated in the organization of the International Tomato, Chinese Cabbage and Watermelon Genome Project. The achievements of these works were published in Nature Genetics (2009,201,20 12) and Nature (201,20 12), which established the field of vegetable genome research in China.
On the basis of genome sequence map, the dominant teams at home and abroad were organized to carry out genome-wide genetic variation research of main vegetables, that is, variation groups. At present, 1 15 cucumber core germplasm and 300 tomato core germplasm have been resequenced, and millions of molecular markers have been found respectively, and the variation group maps of cucumber and tomato have been drawn. The genome sequence map of three kinds of wild potatoes was drawn, and it was found that there were great allelic variations between cultivated potatoes and wild potatoes. The map of variation group laid a solid foundation for the cloning and molecular design breeding of vegetable functional genes, and also helped to further consolidate China's dominant position in vegetable genomics research.
2) Whole genome design and breeding of vegetables.
On the basis of cucumber variation group, 384 SNP markers were screened from more than 4 million markers, and the background selection SNP chip was developed, which is the first SNP chip in vegetable crops. The simulation of more than 50 thousand backcross combinations shows that the chip can effectively select the genetic background of excellent parents in backcross breeding and will play an important role in cucumber genome design and breeding.
Based on the genome sequence map, the genetic mechanism of main agronomic characters of cucumber was deeply studied, and 24 trait genes and QTL were cloned and finely located, which provided molecular targets for design and breeding. The sex-determining gene M, which controls ethylene synthesis in female flowers, was cloned. The genetic and molecular mechanism of bitterness formation of important quality traits was basically clarified, and it was found that the synthesis of bitter substances in leaves was controlled by Bi gene. Bitterness of fruit is the result of bitter substances transported from leaves to fruits, which is controlled by Bt gene. At present, Bi gene has been cloned, and the candidate gene of Bt has also been determined.