A review on breeding and biotechnological advances for tree farming

Abstract

Tree-based farm diversification is vital for climate risk management, resource supply, and farmer livelihoods. Successful agroforestry expansion depends on cultivating economically and ecologically aligned tree species. Long breeding cycles, often spanning several decades, hinder the rapid development of improved tree varieties, making it difficult to respond effectively to changing environmental conditions and market demands. Genetic variation constraints in some tree species limit the range of traits that can be improved through conventional breeding, potentially leaving trees vulnerable to pests, diseases, or changing climates. Additionally, the complex genetics of trees, characterized by polygenic control and genetic interactions, complicate trait selection and breeding decisions. Traditionally, timber and wood product demands were met through natural forest resources, but rapid industrialization and population growth have led to their overexploitation, especially in India. As a result, there is increasing interest in developing improved tree genotypes for integration into farming systems. However, conventional tree breeding is time-consuming, prompting the adoption of biotechnological tools such as marker-assisted selection, GWAS, genome sequencing, genetic engineering, and QTL mapping to accelerate genetic gains and tree improvement. These technologies enhance productivity, product quality, and climate adaptability, supporting the development and widespread adoption of multipurpose agroforestry species to meet diverse economic and ecological needs. Future progress in molecular genetics and genomics is expected to overcome the challenges of breeding trees for integration under farming systems.