BREEDING FOR A BETTER INDUSTRY: NEW BREEDING TECHNIQUES

摘要

Investment in new technologies that compliment or extend traditional plant breeding methods is beginning to impact on variety improvement programs. This paper will seek to highlight the more important of these, and illustrate their current or potential future application in contributing to the sustainability of sugarcane-based industries. DNA molecular markers are being used routinely in some programs for managing germplasm collections, correcting pedigree information and checking the integrity of new hybrid combinations. Molecular breeding using markers putatively linked to stem-borer resistance is being used in South Africa to improve the efficiency of traditional breeding for this important pest, and a larger project to identify and test markers associated with yield components and cane quality is underway. The large database of more than 33 000 genes expressed in sugarcane developed by the SUCEST program in Brazil has identified markers located within genes of known function, and has the potential to be a very valuable additional resource for molecular breeding. The SUCEST database is also providing information on genes that are potential targets for genetic modification to alter sucrose accumulation, carbohydrate metabolism and other traits. Transgenic sugarcane modified for herbicide, insect and viral resistance has been produced in various programs, but no varieties have been commercialised due to intellectual property rights, and fears of consumer pressure. Potential also exists to exploit sugarcane's high biomass yield by using it as a 'factory' to produce biopolymers, Pharmaceuticals and other high value products in conjunction or as an alternative to sugar. In order to capitalise on this potential, strategic decisions will need to be made at Industry level, and partnerships sought with Life Science companies already investing in this area. The increasing development of 'gene-chip' technology, both for analysing expressed genes and for use in high-throughput marker systems is likely to facilitate the application of gene expression and marker data in variety improvement in the future. It must be remembered, however, that sound breeding programs provide the platform through which the potential of new technologies can be realised.