Location: Fruit and Nut ResearchTitle: Mapping quantitative trait loci associated with chilling requirement, heat requirement and bloom date in peach [Prunus persica (L.) Batsch] Author
|Bielenberg, Douglas G.|
Submitted to: New Phytologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/12/2009
Publication Date: 4/1/2010
Citation: Fan, S., Bielenberg, D., Zhebentyayeva, T., Reighard, G.L., Okie, W.R., Holland, D., Abbott, A. 2010. Mapping quantitative trait loci associated with chilling requirement, heat requirement and bloom date in peach [Prunus persica (L.) Batsch]. New Phytologist. 185(4):917-930. Interpretive Summary: Chilling requirement in peach determines when a tree blooms in the spring, and thus to what climate it is adapted. A family of peach seedlings resulting from a cross of very high-chill and very low-chill parents was grown and evaluated for chilling requirement over several years. Each tree was tested to determine the molecular markers present. These markers were then tested for association with the plants chilling requirement. Twenty chromosomal locations were associated with chilling requirement and time of bloom, with 3 of these having a major effect. These results may make it more efficient to select the desired chilling range from seedling trees in a breeding program, without having to grow them out for several years.
Technical Abstract: Chilling requirement (CR), together with heat requirement (HR), determines blooming date (BD) and climatic distribution of genotypes of temperate tree species. However, information on the genetic components underlying these important traits remains unknown or fragmentary. Here the identification of quantitative trait loci (QTLs) for CR, HR and BD in an inbred peach F2 population, which is derived from crossing a high CR elite cv. Contender and a low CR selection Fla.92-2c are reported. A SSR and AFLP-based genetic map of 535cM with 8 linkage groups, which is in agreement with Prunus reference map was constructed. CR, HR of each genotype of the mapping population was evaluated in two years and BD was evaluated in four years. Eight QTLs for CR, two QTLs for HR and nine QTLs for BD were detected. The co-localization of the majority of QTLs for three traits might suggest one unified temperature sensing and action system regulating CR, HR and BD together.