Genetic modification of short rotation popular wood: Properties for ethanol fuel and fiber productions

Opportunities for matching wood chemical and physical properties to manufacturing and product requirements via genetic modification have long been recognized. Exploitation is now feasible due to advances in trait measurement, breeding, genetic mapping and marker, and genetic transformation technologies. With respect to classic selection and breeding of short-rotation poplars, genetic parameters are favorable for decreasing lignin content and increasing specific gravity, but less so for increasing cellulose content. Knowledge of functional genomics is expanding, as is that needed for eventual application of marker-aided breeding, trait dissection, candidate gene identification, and gene isolation. Research on gene transfer has yielded transgenic poplars with decreased lignin and increased cellulose contents, but otherwise normal growth and development. Until effective marker-aided breeding technologies become available, the most promising approach for enhancing ethanol fuel and fiber production and processing efficiencies centers on selecting and breeding poplars for high wood substance yields and genetically transforming them for decreased lignin and increased cellulose contents.