Current Status and Future Perspectives of Genomic Selection for Tropical Timber Species : Insights from Case Studies of Dipterocarps

Tropical forests are vital for global biodiversity, climate regulation, and socio-economic development but face increasing pressures from deforestation, illegal logging, and poor resource management.Tree breeding programs provide a sustainable path forward by improving forest productivity and resilience.However, traditional breeding is limited by long generation intervals and constrained technical capacity, especially for tropical hardwoods such as those in the Dipterocarpaceae family.Advances in genomics, particularly genomic selection (GS), offer new opportunities to accelerate genetic gain.This review examines emerging GS applications in tropical tree improvement, focusing on Eucalyptus, Acacia, and Rubroshorea species.Key requirements for GS include structured training populations, cost-effective genotyping, and high-throughput, nondestructive phenotyping tools such as Light Detection and Ranging.Case studies in Rubroshorea show that trait-specific genetic architecture strongly influences GS accuracy: tree height, controlled by fewer major-effect genes, achieves high predictive accuracy with fewer markers, whereas trunk diameter, a polygenic trait linked to primary and secondary growth, requires denser genotyping.Similar patterns appear in temperate conifers, including Douglas-fir, Norway spruce, and Pinus radiata.These findings underscore the need for tailored genomic strategies based on trait complexity.Moving forward, integrating genomic technologies into breeding programs in the tropics will require coordinated efforts to address logistical, financial, and technical constraints.Nevertheless, GS shows strong promise for improving selection efficiency, climate adaptability, and sustainable timber production in tropical forestry.