Location: Sugarcane Field StationTitle: Evaluation of Sugarcane Orange Rust for first clonal stage of the CP Cultivar Development Program
|DAVIDSON, R - Florida Sugarcane League|
|BALTAZAR, MIGUEL - Florida Sugarcane League|
Submitted to: American Society of Sugar Cane Technologists
Publication Type: Abstract Only
Publication Acceptance Date: 6/10/2014
Publication Date: 12/16/2014
Citation: Zhao, D., Davidson, R.W., Baltazar, M., Comstock, J.C. 2014. Evaluation of Sugarcane Orange Rust for first clonal stage of the CP Cultivar Development Program. American Society of Sugar Cane Technologists. 34:73.
Technical Abstract: Consistent development of high-yielding sugarcane cultivars with resistance or tolerance to biotic and abiotic stresses is critical to commercial sugarcane production in Florida. Currently, orange rust (caused by Puccinia kuehnii E.J. Butler) is a great challenge for the Florida sugarcane production. A better understanding of sugarcane genotypic variability in responses to orange rust disease will help optimize breeding and selection strategies for disease resistance or tolerance. Orange rust ratings were collected from the 2012 and 2013 genotypes in first clonal selection stage (Stage I) of the Canal Point sugarcane breeding and cultivar development program in Florida. Rust ratings were scaled from non-infection (0) to severe infection (4) with intervals of 0.5. Data were collected from all 14,272 and 12,661 unreplicated genotypes and four reference cultivars with >40 replications in July and August of 2012 and 2013, respectively. Mean rust rating, % of infection, and rust severity in each family (i.e., progeny of the cross from a female and male) and female parent and their coefficients of variation (CV) within and among families (females) were estimated. Considerable variation exists in rust rating and % infection among families or females. The mean orange rust ratings across families were 0.4 (ranged from 0.0 to 2.2) in 2012 and 1.0 (ranged from 0.1 to 2.1) in 2013 with CV values of 94 and 47%, respectively. The families that were the most susceptible or resistant to orange rust were identified and ranked. Female parents were also evaluated based on the rust rating in their progeny. Findings of this study are useful for evaluating sugarcane crosses and their parents in response to rust disease and can help breeders use desirable parents for crossing and improve genotypic resistance to orange rust.