Research progress on genetic improvement of Betula platyphylla Suk.

Abstract

Betula platyphylla Suk. is one of the most widely distributed species of Betula, the fourth most valuable timber species in northeastern China and also a common tree species for landscaping. Over the past 30 years, effective progress has been made in genetic improvement and molecular breeding of B. platyphylla. There has been extensive research on breeding techniques, including the collection and conservation of B. platyphylla germplasm resources, provenance trials, intensive breeding techniques, crossbreeding and asexual propagation techniques, ploidy breeding and mutation breeding technology, genome sequencing, gene cloning, transgenic and molecular mechanisms of wood formation. A Betula germplasm resource collection has been established by collecting different provenances, and full-sib and half-sib families. In addition, the geographic variation patterns of B. platyphylla provenances have been revealed, and the provenance division and superior provenance selections made. B. platyphylla flowering and seeding have been improved through intensive breeding techniques. Interspecific hybridization, intraspecific hybridization and parallel crosses were made using fine parents, and B. platyphylla intensive seed orchards have been established. Systems of asexual propagation, including cuttings, grafting and tissue culture have been established. A B. platyphylla tetraploid was successfully constructed and a B. platyphylla triploid seed orchard established. The growth, wood property and resistance genes of B. platyphylla have been cloned. An efficient B. platyphylla transgenic system mediated by Agrobacterium tumefaciens was established, and genes encoding B. platyphylla insect resistance, drought resistance and salt tolerance, lignin synthesis, flowering, hormone transport and balance obtained. B. platyphylla molecular markers were developed and the high density B. platyphylla genetic map constructed. All this research has provided a model and data for the foundation of forest genetic improvement and applied research.

Functional Characterization of PmDXR, a Critical Rate-Limiting Enzyme, for Turpentine Biosynthesis in Masson Pine (Pinus massoniana Lamb.)

“…Turpentine, also known as "the oil that grows on trees", is more than one-third of the total global turpentine production in China, and it has become a major export commodity of Chinese forestry in the world [28]. As a renewable resource, the utilization of turpentine is beneficial to the sustainable development of the national economy.…”