DETECTION OF SEED DORMANCY QUANTITATIVE TRAIT LOCI (QTL) IN PEACH
Dormancy is a condition that delays or inhibits growth in seed, vegetative buds, and floral buds. Growth resumes in vegetative and floral buds after winter bud dormancy has been met by the accumulation of chilling hours and heat units necessary to break endodormancy and ecodormancy, respectively. Seed germination occurs after seed dormancy has been met by sufficient accumulation of stratification hours. A recent study in our lab suggests that the date of seed germination and the same seedlings vegetative and floral bud chilling requirement are not correlated. Correlations have been reported, however, between mean seed stratification requirements and mean bud chilling requirements among families. Prior to this study the number of genes involved in regulating seed dormancy and their location on the peach genomic map was unknown. Segregating F2 seed was collected from a high x low stratification requirement F1 hybrid in 2005, 2006 and 2008. Three experiments were performed in which batches of seed received varying amounts of stratification. Data on seed germination response, time of germination, and seedling development was collected. Genomic DNA from resulting plants was extracted and screened with SSR markers selected from the Prunus genomic map at an average resolution of 20 cM. Seed dormancy QTL were compared with previously detected vegetative and floral bud dormancy QTL. Seed dormancy QTL specific to stratification requirement and germination time were detected. A QTL region common to both seed stratification requirement and vegetative bud chilling requirement was found.
Blaker, K.M. and Chaparro, J.X. (2012). DETECTION OF SEED DORMANCY QUANTITATIVE TRAIT LOCI (QTL) IN PEACH. Acta Hortic. 962, 143-146
Prunus persica, chilling, genome