Submitted to: Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/2/2001
Publication Date: N/A
Interpretive Summary: Oat is one of the major cereal grains and is considered to be a healthy and nutritious food as well as a useful feed and fodder crop. Detailed and complete molecular maps have been constructed for other major cereal grains. Due to its genetic complexity, the current map of oat is not as complete as other cereal grains. To solve this problem, it is thought that additional mapping information from a number of different crosses will be needed to be combined to make a composite reference map for oat scientists to further study the complex oat genome. This mapping study was conducted to add a portion of the information needed to put together a composite reference map for oat. Once the composite reference map is assembled, oat geneticists will be better able to locate loci controlling economically important genes. Once the probable location of trait genes is determined, nearby molecular markers can be tested for their ability to track the genes controlling traits such as disease resistance, oil and fiber content, and antioxidant levels. This information can then be used by geneticists to enhance oat germplasm for specific end uses.
Technical Abstract: A cultivated oat linkage map was developed using a recombinant inbred population of 136 F6:7 lines from the cross Ogle x TAM O-301. A total of 441 marker loci, including 355 RFLP, 40 AFLP, 22 RAPD, five STS, one SSR, 12 isozyme loci, and four discrete morphological traits, was mapped. Fifteen loci remained unlinked, and 426 loci produced 34 linkage groups (with two to 43 loci each) spanning 2049 cM of the oat genome (from 4.2 - 174.0 cM per group). Comparisons to other Avena maps revealed 35 genome regions syntenic between hexaploid maps and 16 to 34 regions conserved between diploid and hexaploid maps. Those portions of hexaploid oat maps that could be compared were completely conserved. Considerable conservation of diploid genome regions on the hexaploid map also was observed (89 - 95%); however, at the whole- chromosome level, colinearity was much lower. Comparisons among linkage groups, both within and among Avena mapping populations, revealed several putative homoeologous linkage group sets as well as some linkage groups composed of segments from different homoeologous groups. The relationships between many Avena linkage groups remain uncertain, however, due to incomplete coverage by comparative markers and to complications introduced by genomic duplications and rearrangements.