Submitted to: Plant Genetic Resources: Characterization and Utilization
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/15/2010
Publication Date: 4/15/2011
Citation: Huang, Y. 2011. Improvement of crop protection against greenbug using the worldwide sorghum germplasm collection and genomics-based approaches. Plant Genetic Resources: Characterization and Utilization. 9(2):317-320. Interpretive Summary: Great success in crop improvement for pest management has been made in the past. However, the current efforts to improve crop resistance through the conventional methods have had limited success due to the lack of genetic sources and genes for resistance, the genetic complexity of host-pest interactions, and a poor understanding of host resistance mechanisms underlying the host defense responses. At the same time, climatic changes may aggravate the conditions of growth in less favorable locations. Thus, these developments will result in a significant increase in problems caused by biotic and abiotic stresses, which will inevitably limit crop performance and yield levels. Our current research program aimed at the improvement of sorghum crop against insect pests using the worldwide germplasm collection and genomics-based approaches. To accomplish this research goal, we first searched available germplasm collections, leading to the identification of 21 new resistant lines, which offer additional sources to sorghum breeding. Then, we have adopted the post-genomic technologies to dissect plant-pest interactions and to identify insect resistance genes in host plants. Those genomic tools, such as use of the microarray technology for analyzing genome-wide gene expression profiles and development of DNA markers for facilitating gene identification and marker-assisted breeding, proved to be the major keys in capturing the promising benefits of crop genomics and biotechnology.
Technical Abstract: Successful development of new sorghum cultivars and hybrids to ensure sustainable production depends largely on the availability of genetic resources with desirable traits such as pest resistance. Our recent research has focused on improvement of crop protection against greenbug using worldwide germplasm collection and genomics-based approaches. First, we have completed the systematic evaluation of the entire U.S. sorghum germplasm collection in order to identify new sources of greenbug resistance, leading to the identification of 21 resistant lines, which offer additional sources to sorghum breeding. Molecular markers were used to assess the genetic diversity among those resistant lines, suggesting relatively diverse resistant sources in the sorghum germplasm collection. Furthermore, a mapping project was executed more recently to dissect the resistance genes onto sorghum chromosomes. The mapping data indicated that one major and a minor QTL resided on chromosome nine are responsible for resistance to greenbug. In addition, cDNA microarrays were used to monitor greenbug-induced gene activities in sorghum plants. This study has developed a transcriptional profile for sorghum in response to greenbug attack, which provides us with the useful molecular information for discovery of greenbug resistance genes and a better understanding of the genetic mechanisms controlling host defense in sorghum crop.