|Miklas, Phillip - Phil|
Submitted to: Bean Improvement Cooperative Annual Report
Publication Type: Research notes
Publication Acceptance Date: 2/1/2002
Publication Date: 5/1/2002
Citation: MIKLAS, P.N., KELLY, J.D. THE USE OF MAS TO DEVELOP INTO BEAN GERMPLASM POSSESSING CO-4(2) GENE FOR ANTHRACNOSE RESISTANCE. BEAN IMPROVEMENT COOPERATIVE ANNUAL REPORT, 45:69-69. 2002. Interpretive Summary: Bean anthracnose, a seed-borne fungal disease, is problematic worldwide, but has been a serious problem for dry edible bean producers in Michigan and New York for many years. The disease can cause up to 100 percent crop loss and decreases quality of harvested seed. Chemical control is not effective. This endemic problem lead to the development of genetically resistant navy, black, and kidney bean cultivars for the Great Lakes production region. A bean anthracnose outbreak was reported in North Dakota in 2001. The annual average production of 400,000 acres of pinto bean grown in the Red River Valley of North Dakota and Minnesota are completely susceptible to this disease, and thus at substantial risk for complete crop failure. Using marker-assisted selection techniques we were able to quickly transfer the Co-42 gene from an unadapted tropical black bean into an adapted pinto bean in less than 18 months. Co-42 is the most effective resistance gene identified to date. The enhanced lines described above wil be most useful for protecting the $55 million pinto bean industry (farm- gate value) in the Red River Valley from emerging anthracnose disease. This study illustrates the utility of marker-assisted selection for enabling the quick deployment of a resistance into a region to circumvent substantial crop loss and reduce expansion of an emerging disease problem.
Technical Abstract: Anthracnose, caused by Colletrotrichum lindemuthianum (Sacc. & Magnus), is a major seed-borne disease of beans in Michigan, New York and Ontario. In 2000, anthracnose was observed in pinto bean fields in Manitoba, and this outbreak moved into neighboring North Dakota in 2001. Herein we describe the development of pinto bean lines with Co-42 resistance to anthrancose disease using marker-assisted selection (MAS). Co-42, with a Resistance Index of 97 (resistant to 33 of 34 races), is the most effective anthracnose resistance gene characterized to date. The gene was moved into pinto bean using a MAS "pseudo" backcrossing scheme. "Pseudo", because a different pinto parent was used for each backcross. The primers for the SAS13950 SCAR are as follows: forward= CAC GGA CCG AAT AAG CCA CCA ACA and reverse = CAC GGA CCG AGG ATA CAG TGA AAG. The thermal cycling profile = 34 cycles of denaturing for 10s at 94oC, annealing for 144s at 72oC, and a final extension cycle of 5 min at 72oC. Actual phenotypic selection (disease screening) for resistance to anthracnose was not conducted until the BC3F2:3 generation. The identification of true breeding anthracnose resistant BC3F2:3 progenies indicated that MAS-backcrossing successfully introgressed Co-42 from the unadapted SEL 1308 breeding line into adapted pinto bean. Adapted pinto bean lines with Co-42 resistance to anthracnose, developed by MAS, are in the process of being officially released by USDA- ARS in cooperation with the Michigan Agricultural Experiment Station. The enhanced lines described above will be most useful for protecting the 400,000 acres of susceptible pinto bean production in the Red River Valley from emerging anthracnose disease. Until seed increases of the potential releases are completed, for now, only small 5 seed samples are available.