Development of Genomic Resources and Assessing Their Potential for Accelerated Acacia Breeding

Abstract

Acacia is an important plantation crop in the world for pulp, timber, afforestation of degraded lands, controlling desertification, and reclamation of poor sandy soils due to its nitrogen fixing ability. However, the genome structure and organization of this plant is poorly understood, thereby limiting the effective use of its genetic resources. The Acacia hybrid (Acacia mangium × Acacia auriculiformis) has been found to be more desirable than its parents with tolerance to diseases, lower lignin, better tree form, longer fibre and higher adaptability. Therefore the Acacia hybrid is of high potential for sustainable productivity, particularly under changing climatic conditions. Elite planting materials of the Acacia hybrid can be developed efficiently through marker-assisted breeding. The understanding of its genome and development of DNA markers are crucial to accelerate the breeding of Acacia. We attempted to understand the lignin biosynthesis and wood formation in the Acacia species through genomics approaches (EST, microRNA and transcriptome sequencing). At the same time, we have developed various DNA markers (SSR, CAPS and SNP) and established two mapping populations (wood density and fibre length) for linkage mapping and quantitative trait locus (QTL) analysis. We have obtained QTLs for four main agronomic traits (wood density, plant height, diameter at breast height and biomass) for the breeding of Acacia with better wood and fibre properties in the future through marker-assisted breeding and gene manipulation.