SORGHUM FUNGAL PATHOGEN BIOLOGY AND DISEASE RESISTANCE
Location: Crop Germplasm Research
Title: Evaluation of sorghum germplasm from China against Claviceps africana, causal agent of sorghum ergot
Submitted to: Plant Health Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 19, 2008
Publication Date: May 19, 2008
Citation: Prom, L.K., Erpelding, J.E., Montes-Garcia, N. 2008. Evaluation of sorghum germplasm from China against Claviceps africana, causal agent of sorghum ergot. Plant Health Progress (online). doi:10.1094/PHP-2008-0519-01-RS.
Interpretive Summary: Sugary disease of sorghum or sorghum ergot, a fungal disease that was first observed in the United States in 1997, poses a serious threat to sorghum, especially in hybrid seed production fields. So far, no sorghum line with resistance to the disease has been identified. This study was conducted using 40 sorghum lines from the Chinese sorghum germplasm collection stored at the USDA-ARS, Plant Genetic Resources Conservation Unit, Griffin, Georgia, to identify potential ergot resistant sources. Four Chinese accessions, PI63923, PI511832, PI610749, and PI610688, recorded the lowest ergot infection. These lines may possess genes for ergot resistance. However, studies are underway to confirm if the resistance is pollen based.
Forty Chinese sorghum landraces maintained by the USDA-ARS, Plant Genetic Resources Conservation Unit, Griffin, Georgia were evaluated for ergot resistance at the Texas A&M Research Farm, College Station, Texas, during the 2005 and 2006 growing seasons. The male sterile line, ATx623, was included as a susceptible control and three IS8525 derived lines were included as resistant controls. The disease infection level was low in the susceptible check in 2005 due to unfavorable environmental conditions, but the majority of the Chinese accessions showed a higher level of tolerance than the resistant controls. In contrast, infection severity was high in 2006. The IS8525 resistant controls averaged 25% infection compared to an average infection of 18% for the 40 Chinese accessions. Four Chinese accessions, PI63923, PI511832, PI610749, and PI610688, recorded less than 10% ergot infection. Thus, these four sorghum accessions may possess genes for ergot resistance. Further research is underway to evaluate these accessions under multi-environments to confirm resistance and to determine if the resistance is associated with pollination characteristics.