Submitted to: Plant Health Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 31, 2010
Publication Date: November 23, 2010
Citation: Erpelding, J.E. 2010. Anthracnose resistance in sorghum breeding lines developed from Ethiopian germplasm. Plant Health Progress. DOI: 10.1094/PHP.20101-11233-02-RS. Interpretive Summary: Anthracnose is one of the most important fungal diseases affecting sorghum production worldwide and germplasm from Africa is a valuable resource for the identification of new sources of resistance. However, most sorghum germplasm from Africa is tall and sensitive to day length; thus, making it more difficult to utilize this germplam in breeding programs. The genes controlling dwarf plant height and day length insensitivity can be transferred into tall, day length sensitive sorghum germplasm to developed adapted breeding lines. These breeding lines will flower when planted during the summer in the United States and could be an important source of host-plant resistance for the development of anthracnose resistant grain sorghum varieties. The development of these breeding lines was initiated in 1963 as a collaborative project between the USDA-ARS and the Texas Agricultural Experiment Station, with population developed conducted in Puerto Rico during the winter and selection of dwarf and day length insensitive lines conducted in Texas during the summer. The project developed 703 breeding lines from 1963 to 2004. To identify lines with resistance to anthracnose, 99 breeding lines developed from Ethiopian sorghum germplasm were evaluated at the USDA-ARS, Tropical Agriculture Research Station in Isabela, Puerto Rico during the 2008 and 2009 growing seasons. Approximately 44% of the lines showed resistance to anthracnose across the two growing seasons. Ethiopia is a major center of diversity for sorghum and these resistant lines could provide new genes for disease resistance.
Technical Abstract: Ninety-nine dwarf and photoperiod-insensitive breeding lines developed from Ethiopian sorghum germplasm were inoculated with Colletotrichum sublineolum and evaluated for anthracnose resistance at the Tropical Agriculture Research Station in Isabela, Puerto Rico during the 2008 and 2009 growing seasons. A resistant response was observed for 57 lines in 2008 and for 47 lines in 2009 with 44 lines showing a resistant response across growing seasons. These lines showed reddening of inoculated leaves and no acervuli. Variation in resistance across growing seasons and replications within a growing season was observed for 19 lines rated as susceptible and these lines also showed low disease severity. Mean disease severity for the susceptible accessions was similar across growing seasons with a mean of 26% for 42 lines in 2008 and 23% for 52 lines in 2009. The resistant lines showed phenotypic diversity in response to anthracnose, suggesting potential genetic variation for resistance.