Evaluating target spot (Corynespora cassiicola) resistance in soybean (Glycine max (L.) Merrill) in a controlled environment. (September 2022)

• Record Type: Journal Article
• Authors: Patel, S.J.; Bowen, K.L.; Patel, J.D.; Koebernick, J.C.
• Is Part Of: Crop protection. Volume 159(2022)
• Publication Date: 2022-09
• Subjects: Target spot -- Resistance; Plants, Protection of -- Periodicals; 632.05
• DOI: 10.1016/j.cropro.2022.106018
• Languages: English
• ISSNs: 0261-2194

Abstract

Abstract: Target spot, caused by the fungus Corynespora cassiicola, has been an increasing problem for soybean growers in the Mid-south and southeastern United States. With favorable environmental conditions, the disease causes premature defoliation and substantial yield losses; therefore, identifying resistant germplasm is critical. Herein, a rapid screening technique for target spot resistance was used to evaluate varieties for possible use in a breeding program. Fifteen soybean varieties, along with a known susceptible variety, were evaluated against isolate C. cassiicola LIM01. Two of the sixteen varieties were identified as resistant and nine were moderately susceptible. A subset of these was evaluated with three additional C. cassiicola isolates; these isolates differed in combinations of cassiicolin-encoding genes. The soybean varieties Bedford and Council were observed to be resistant to each of the C. cassiicola isolates tested in this study but need to be further validated in a field environment. Plant populations developed using these parent varieties could provide a foundation for QTL mapping of regions conferring resistance to target spot and identifying disease resistance mechanisms that can be transferred into elite soybean varieties through marker-assisted breeding. Highlights: Target spot is an emerging problem for soybean growers in the southern United States. Soybean varieties were evaluated for disease resistance using five C. cassiicola isolates. Bedford and Council were found resistant to C. cassiicola in greenhouse condition. Response to iron chlorosis and target spot might share a common biological pathway.