Location: Sugarcane Field StationTitle: Impact of pathogen genetics on breeding for resistance to sugarcane diseases Author
Submitted to: International Society of Sugar Cane Technologists Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 12/11/2012
Publication Date: 6/22/2013
Publication URL: http://handle.nal.usda.gov/10113/56993
Citation: Rott, P.C., Girard, J.C., Comstock, J.C. 2013. Impact of pathogen genetics on breeding for resistance to sugarcane diseases. International Society of Sugar Cane Technologists Proceedings. 28:1-11. Interpretive Summary: The paper reviews and describes the state of knowledge of the genetics of sugarcane pathogens and sugarcane. There are explanations of the differences in the severity of disease development because of the interaction of pathogens, hosts under specific environmental conditions. The pathogen-host interaction determines if resistance is durable or transient. The paper indicates the complexity of the sugarcane genome and reports on the recent progress that has been made in its understanding and that of the pathogen genetics. With the increased ability to sequence the genome of pathogens and that of sugarcane the breeding for resistance should be enhanced.
Technical Abstract: Diseases are limiting factors of sugarcane production and breeding for resistance to diseases is a major goal in sugarcane variety improvement. Diseases result from complex interactions between plants, pathogens and environment, including humans and insect vectors of pathogens. History has shown that durability of resistance of sugarcane to diseases varies according to the host cultivar and to the pathogen in a given environment. Some sugarcane cultivars have been grown for decades without losing efficiency of resistance to the disease they were bred or screened for, others became susceptible and showed disease symptoms rapidly after being grown commercially. Disease outbreaks and breakdown or overcoming of plant resistance suggesting changes in the pathogen populations have been observed for several sugarcane diseases. Emergence of new pathogens or new strains of a pathogen generally results in a change of the varieties grown in a sugarcane growing area. Pathogen population genetics must therefore be taken into consideration for breeding and screening new sugarcane varieties for resistance to diseases. Knowing the genetic diversity of a pathogen in a given location is very important, especially when plants are artificially inoculated with pathogens for screening. Furthermore, sugarcane genetics is very complex and few disease specific resistance genes have been identified so far, and selection for these traits is also complex. Sequencing and analysis of genome variation of sugarcane pathogens varying in virulence should result, in the future, in the identification and comprehension of the molecular determinants involved in these genetic changes, and subsequently also facilitate breeding for resistance.