Submitted to: Kasetsart Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 6, 2009
Publication Date: N/A
Interpretive Summary: As recent advances in the areas of plant genetics and genomics, significant progress has been made in the similar research with sorghum. Sequencing of the sorghum genome has been recently completed, which is the second completed sequence in crop plants after rice. Sorghum genome sequence shows immense potential for both gaining a better understanding of sorghum genetics and discovering agronomically important genes such as high water-use efficiency and excellent drought tolerance. Genetic linkage maps have been developed for sorghum using SSR (simple sequence repeats or alternatively microsatellites) markers. In addition, molecular markers are increasingly being used to tag genes or quantitative trait loci (QTLs) of agronomic importance, offering the possibility of their uses in marker-assisted selection (MAS) for breeding and for map-based gene cloning. Moreover, molecular resources such as DNA microarrays and enormous expressed sequence tags (ESTs) have been developed to facilitate gene discovery and functional studies of newly identified genes, particularly at a systematic exploration of the whole genome system. Today, genomics research is generating new knowledge about the biology of crop plants and is also offering a set of novel tools for manipulating genetic improvement of crop. This article reviews some of the highlights of modern genomic technologies and discusses the potential applications of these cutting-edge technologies in genomics-assisted breeding for sorghum improvement.
Technical Abstract: Sorghum (Sorghum bicolor L. Moench), a leading cereal crop, has the important role as staple food, animal feed, construction material, and fuels in developed and developing countries. Recently, the new use of sorghum as renewable feedstocks for biofuels has been promoting more global interest in sorghum. All of these are creating a growing demand for the production and the quality of sorghum, which depends totally on improved or new cultivars/hybrids. Today, we face a new challenge in the crop production because the rate of crop improvement through the conventional process is not able to accommodate the rate of demand increase. However, the recent advances in crop molecular genetics and emerging genomics technologies have substantially expanded our ability to analyze and understand the sorghum genome and to reduce the gap existing between genotype and phenotype. Moreover, the recent completion of whole genome sequencing of sorghum opened the doors for more efficient gene discovery and offers us the opportunities to translate the genome information into improvement of crop through various breeding strategies. This paper reviews the advances of our knowledge and these newly-developing technologies, such as development and utilization of the genomic resources for gene discovery, plant genotyping and QTL (quantitative trait loci) identification, development of DNA markers and marker-assisted selection, gene expression profiling and dissecting the network of gene regulation, and plant functional genomics. Finally, the paper will demonstrate the use of new tools in sorghum breeding to allow more precise, more quickly manipulated, more easily measured, and more beneficial traits to be added to sorghum crops around the world.