Thoughts on tree breeding strategies

The low level of plantation cultivation in China is due to insufficient investment in manpower and financial resources in the field of tree breeding, and insufficient attention and implementation of breeding strategies. It leads to the difficulty of maintaining the basic breeding cycle of tree genetic improvement, and can not sustain the continuous improvement of the genetic improvement level of trees and the improvement of plantation productivity. This article comprehensively analyzed the development experience, theory and technology achievements of tree breeding at home and abroad, and put forward several issues that need to be paid attention to in the formulation and implementation of tree breeding strategies. Varieties have regionality, temporality and economic attributes. Ecological value belongs to the subsidiary benefits of planting improved varieties. It is necessary to formulate breeding objectives and breeding cycles that are scientific, specific and have certain market competitive advantages. On this basis, the construction and management of base population, selected population and breeding population of tree species should be strengthened. Scientific experimental design and analysis methods should be adopted to ensure accurate and efficient genetic testing and selection. We should continuously push on the construction of advanced-cycle breeding population, and rationally adopt techniques such as promoting flowering and fruiting, related selection or marker assisted selection to accelerate the process of mating and selection, continuously improve the genetic quality of base populations and selected populations, and even achieve the production and application of distant hybrid varieties with super-strong advantages. For the species that can reproduce asexually, physical and chemical mutagenesis and chromosome doubling can be applied at a certain stage of genetic improvement to further increase the accumulation and utilization of beneficial mutations. For the excellent varieties that have been applied to production but still have insufficient, further optimization can be carried out by molecular breeding such as genetic transformation and gene editing. Mating, genetic testing and selection are the core of the breeding cycle and the basis for further implementation of other breeding techniques, which need to be given more attention.