Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/28/2000
Publication Date: N/A
Interpretive Summary: A major challenge to plant breeders trying to improve a crop plant is that most traits of special interest are under complex genetic control and the exact genes controlling the traits are not known. Recently developed techniques for isolating and characterizing small pieces of DNA, the genetic material, have provided a powerful indirect method for "tagging" genes. Such tags enable geneticists to follow genes influencing complex traits, such as protein concentration, through genetic crosses and to select for the presence of desirable forms of the genes in offspring. We compared the behavior of a new type of DNA tag in two sets of crosses in the cereal oat and found that there is sufficient consistency in its behavior to make it a useful tool for oat breeders. This type of tag, termed AFLP for amplified fragment length polymorphism, is more versatile and efficient to use than the type of DNA tag previously used. Thus, breeders of oats and other cereals can now more confidently adopt this new gene tagging technology as a tool for use in analyzing the genetic composition of oat parent lines and in making selections for progenies with better disease resistance, yield, and seed quality.
Technical Abstract: Amplified fragment length polymorphisms (AFLPs) can be used to quickly develop linkage maps in plant species and are especially useful for crops with large genomes like oat (Avena sativa L., 2n=6x=42). High reproducibility and consistency are crucial if AFLP linkage maps are employed for comparative mapping. We mapped AFLP markers in combination with restriction fragment length polymorphism (RFLP) markers in two recombinant inbred populations of hexaploid oat in two laboratories to test the consistency of AFLP markers in a polyploid crop. Eight primer combinations produced 100 to 120 AFLP markers. In a population from the cross 'Kanota' x 'Ogle', AFLP markers were placed onto a RFLP reference map consisting of 32 linkage groups. Nineteen linkage groups from another population from the cross 'Kanota' x 'Marion' were assigned to the reference map using AFLP and RFLP markers homologous to those used in the 'Kanota' x 'Ogle' cross. Reproducibility of AFLP assays was high in both laboratories and between laboratories. The AFLP markers were well distributed across the genome in both populations. Of the 27 AFLP fragments common in both populations, 20 mapped to homologous linkage groups, 4 were unlinked in at least 1 population, and 3 mapped to different linkage groups in the 2 crosses, even though sequencing analysis confirmed that 3 represented identical fragments. We believe that one of the three markers that mapped to a different linkage group in the two populations mapped to homoeologous linkage groups. AFLPs provide not only a fast and powerful tool for mapping, but also could be useful in characterizing genomic structural variations among germplasms in hexaploid oat.