Submitted to: Open Agriculture Journal
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/20/2008
Publication Date: 12/18/2008
Citation: Erpelding, J.E. 2008. Field evaluation of anthracnose resistance for sorghum germplasm from the Sikasso region in Mali. The Open Agriculture Journal. (2):113-120. Interpretive Summary: Anthracnose is an important fungal disease of sorghum and grain yield losses of more than 50% have been reported. Anthracnose infection is typically observed on sorghum leaves, but the pathogen can infect the stalk, panicle, and seed. Yield losses caused by the disease can be minimized through the use of resistant cultivars, but frequent changes in the pathogen population can result in a loss of resistance. Thus, the identification of additional sources of resistance is essential for the development of new resistant cultivars. An important source of anthracnose resistance is the USDA, ARS National Plant Germplasm System sorghum collection. Screening the sorghum germplasm collection for anthracnose resistance is underway. In this study, the sorghum collection from the Sikasso region of Mali was evaluated for anthracnose disease response at the USDA, ARS Tropical Agriculture Research Station in Isabela, Puerto Rico. From the 132 germplasm lines evaluated, 109 showed a resistant response when inoculated with the pathogen; thus, indicating that the Sikasso region of Mali could be an important source for anthracnose resistant germplasm. Additionally, the results from the anthracnose field evaluation showed that anthracnose resistant germplasm was more frequently associated with regions receiving higher annual rainfall.
Technical Abstract: The USDA, ARS National Plant Germplasm System maintains 132 sorghum landraces from the Sikasso region of Mali. This germplasm was inoculated with Colletotrichum sublineolum and evaluated for foliar anthracnose resistance at the USDA, ARS Tropical Agriculture Research Station in Isabela, Puerto Rico during the 2004 and 2005 growing seasons. A resistant response was observed for 109 accessions. For the 32 susceptible accessions, infection severity was low with an average infected leaf area of 5.6%. Only one accession was rated as highly susceptible. Anthracnose resistant germplasm was more frequently associated with the southern administrative districts that experience higher annual rainfall. More than 80% of the accessions from the Bougouni and Sikasso districts conferred a resistant response. The lowest average infection severity, 1.5%, was observed for accessions from the Sikasso district. In comparison, 71% of the accessions from the drier, northern Koutiala district conferred a resistant response. Nearly all landraces from the Sikasso region were classified as race guinea and the guinea landraces that were further classified as margaritiferum were all rated as resistant. Results indicate that the Sikasso region of Mali could be an important source of anthracnose resistant germplasm and that race classification could be used to select germplasm for additional disease evaluation.