China News Service Haikou February 15 (Reporter Wang Xiaobin) The molecular breeding team of the rubber research Institute of the Chinese Academy of Tropical Agricultural Sciences (CASS), in collaboration with the North China University of Science and Technology, has proposed a possible mechanism for the rapid increase of the yield of the genome hybrid in the early domestication of rubber trees, according to the report on Monday.
Rubber trees have been cultivated in Southeast Asia for less than 150 years, and the founders of the widely-cultivated Weikehan varieties only have 9 mother trees. In the short history of domestication, related varieties experienced genetic bottleneck effect. At present, artificial breeding of hevea sinensis has been carried out for 4 generations, and its yield has increased by 6 times. However, the mechanism of variety domestication and yield increase has not been systematically studied.
Cheng Han, a researcher at the Rubber Research Institute of the Chinese Academy of Thermal Sciences, said it would take 30 years to breed new rubber trees using traditional methods. Without the knowledge of the rubber tree genome, the process is like that of a very slow blind person groping an elephant. Therefore, molecular breeding of rubber tree is the main direction of the industry.
Molecular breeding requires mastering the genomes of related species. Cheng Han said that in the key research, the team's researchers assembled high-quality genome sequences of wild rubber trees for the first time, which significantly improved the integrity of the rubber tree genome assembly compared with published genomes. In addition, through the population genome analysis of 147 germplasm resources by genome resequencing, the team found that the Weikehan species diverge slightly from the wild resources, and the six related species in the classical taxonomic sense are likely to belong to the same species as the Brazilian rubber tree. In the further study, we found the possible mechanism of the rapid increase of the yield of genomic hetero in the early stage of domestication.
"Along the lines of our current research, we are working to improve the breeding model of rubber trees so that we can accurately predict the yield performance of rubber trees at seedling stage." Ideally, the breeding cycle of rubber trees could be reduced to less than 10 years, Cheng said. (finish)
