|Miklas, Phillip - Phil|
Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/2002
Publication Date: 4/1/2003
Citation: MIKLAS, P.N., COYNE, D.P., GRAFTON, K.F., MUTLU, N., REISER, J., LINDGREN, D.T., SINGH, S.P. A MAJOR QTL FOR COMMON BACTERIAL BLIGHT RESISTANCE DERIVES FROM THE COMMON BEAN GREAT NORTHERN LANDRACE CULTIVAR MONTANA NO. 5. EUPHYTICA, 131:137-146. 2003. Interpretive Summary: Common bacterial blight is a serious seed-borne disease of dry bean worldwide. This disease alone was responsible for the establishment of the western bean seed industry in Idaho, Washington, and California about 60 years ago. Millions of dollars in yield loss annually results from this disease in the midwestern U.S. For nearly 45 years, a major source of resistance to common bacterial blight disease in dry bean was thought to derive from an interspecific cross with the distantly related species ¿tepary bean. This pioneering work led to additional interspecific crosses with tepary bean, which resulted in even higher levels of blight resistance being transferred to dry bean. Recently, markers linked with the genes have been identified and used to trace back and confirm the origin of resistance to this problematic disease. The origin of resistance from the first interspecific cross was not tepary bean as previously thought, but the dry bean cultivar Montana No.5 that was selected from a great northern landrace cultivar belonging to the Mandan Indians of North Dakota. This is a first report of dry bean as an important source of common blight resistance. The systematic combination of this resistance with other sources should continue to produce bean cultivars with superior levels of bacterial blight resistance saving growers from losing millions of dollars due to lost yield and reduced quality.
Technical Abstract: Knowledge of the evolutionary origin and sources of pest resistance genes will facilitate gene deployment and development of crop cultivars with durable resistance. Our objective was to determine the source of common bacterial blight (CBB) resistance in great northern dry bean cultivars. Several cultivars including GN#1, GN#1 Sel 27, and Montana No.5 (the female parent of the common x tepary bean interspecific population from which GN #1 and GN # 1 Sel 27 were derived) and known susceptible checks were evaluated for CBB reaction in field and greenhouse environments. These genotypes and Tepary #4, the male parent and presumed contributor of CBB resistance to GN#1 and GN#1 Sel 27, were assayed for presence or absence of three SCAR markers tightly linked with independent QTLs conditioning CBB resistance. The SAP6 SCAR marker co-segregated (R2=35%) with the CBB resistance in the Montana No.5/Othello (susceptible) F2 population. None of the tepary bean specific CBB resistance-linked SCAR markers were present in GN#1, GN#1 Sel 27, or Montana No.5. Results clearly indicate Montana No.5, a selection from the Mandan Indian landrace, not tepary bean, as the source of CBB resistance in great northern cultivars.