Molecular genetic mapping of dwarfing genes in oat

Abstract

 Restriction fragment length polymorphism (RFLP) analysis provides a valuable tool for characterizing and understanding relationships among genes for useful traits in crop species, particularly in ones with complex genomes such as the hexaploid cultivated oat Avena sativa L. (2n=6x=42). Using Bulked Segregant Analysis (BSA) and F₂ RFLP linkage data, we mapped three dominant oat dwarfing loci to different regions of the oat genome. Dw6, in oat line OT207, is 3.3±1.3 cM from the Xumn145B locus, which has not been placed on the hexaploid oat linkage map. Dw7, in line NC2469-3, is 4.3±2.3 cM from Xcdo1437B and 33±4.1 cM from Xcdo708B. This places Dw7 to linkage group 22. Dw8, in the Japanese lines AV17/3/10 and AV18/2/4, mapped 4.9±2.2 cM from Xcdo1319A in an AV17/3/10בKanota’ F₂ population and 6.6±2.6 cM from it in an AV18/2/4בKanota’ population. This places Dw8 to linkage group 3. Aneuploid analysis of markers linked to the dwarfing genes located Dw6 on the smallest oat chromosome (chromosome 18) and Dw7 on the longest satellited chromosome (chromosome 19). The RFLP markers closely linked to the three dwarfing genes identify distinct regions of the oat genome that contribute to plant height and they should be useful in characterizing new genetic sources of dwarfness in oat.