Poster: Temperature Responses

Abs # 199: Allele structure of the ROOTCARI locus in populations of diploid and tetraploid alfalfa (Medicago sativa L.)

Presenter:	Milton, Angenee
Authors	Milton, Angenee  (A)   Henderson, Tangilla  (A)   Cunningham, Suzanne  (B)   Volenec, Jeffrey M (B)   Gana, Joyce Ache  (A)
Affiliations:	(A): Chicago State University (B): Purdue University

Alfalfa contains a cold acclimation responsive gene, ROOTCAR1, whose product is associated with alfalfa fall dormancy and winterhardiness. We tested the hypothesis that the allele structure of the ROOTCAR1 locus differed between tetraploid alfalfa germplasms differing in fall dormancy and winterhardiness, and then we compared these allele structures to diploid alfalfa. Primers that flanked the ROOTCAR1 promoter sequence were used to amplify ROOTCAR1 DNA fragments from individual plants of alfalfa populations, and the resulting PCR products were analyzed by agarose gel electrophoresis. We found that the diploid alfalfa showed one band in agarose gel, but members of the tetraploid alfalfa populations showed two to four strong bands. Interestingly, a fall dormant winter hardy population, CUFL3, showed a band shift when compared to CUF 101 its non-dormant winter susceptible parent from which it was selected. Our results suggest that the ROOTCAR1 locus has undergone extensive rearrangement in different alfalfa populations perhaps reflecting duplication or deletion events within the alfalfa genome.