DNA marker for oat dwarfing gene

Abstract

Short and stiff straw is one of the principal aims in oat cultivar breeding. Some dwarfing genes are available for backcrossing programmes. Selection efficiency could be improved by marker assisted selection (MAS) especially when the dwarfing gene is dominant, since the recessive allele causing tall phenotype can be hidden and segregate in further generations. Finnish spring oat cultivar Aslak (Boreal Plant Breeding Ltd.) was crossed with the Dutch cultivar Kontant (bred by Zelder BV. and represented by Wiersum BV.) containing a dwarfing gene. One F1 seed produced a progeny of 111 plants. Plants heights were measured and DNAs extracted. Bulked segregant analysis was used to find markers linked to the dwarfing gene. About 500 RAPD (randomly amplified polymorphic DNA) primers were first tested in the parents for polymorphisms. Polymorphic primers (60) were tested in the short and the tall bulk, which were constructed from pooled DNAs of 9 of the shortest and 9 of the tallest F2 plants. Primers, which revealed polymorphism also between the bulks were further analysed in individual plants of the bulks. One polymorphic marker was present in eight of the nine plants of the short bulk but only in one plant of the tall bulk. When this marker was scored in the whole population, it showed significant linkage to height: only 10 plants (9%) were misclassified. This dominant RAPD marker was converted into a more reproducible and codominant SNP (single nucleotide polymorphism) marker. The SNP marker can be used to facilitate selection for homozygous short individuals in those breeding programmes, which contain lines carrying the dwarfing gene originated from the cultivar Kontant.