Location: Vegetable Crops Research Unit
Title: Genetics of carbohydrate accumulation in onion Authors
Submitted to: National Allium Research Conference
Publication Type: Abstract Only
Publication Acceptance Date: November 5, 2008
Publication Date: January 23, 2009
Citation: Raines, S., Havey, M.J., Henson, C.A. 2009. Genetics of carbohydrate accumulation in onion [abstract]. National Allium Research Conference. p. 21. Technical Abstract: Fructans are soluble carbohydrates composed of fructose chains attached to a basal sucrose molecule and act both as health-enhancing pro- and pre-biotics. In onion, higher fructan concentrations are correlated with greater soluble solids content, dry weights, and pungency. We analyzed dry weights and soluble carbohydrates from replicated field trials of two onion families segregating across chromosome regions known to affect carbohydrate concentrations. One region on chromosome 8 controlled the ability of onion to accumulate fructans. One region on chromosome 5 conditioned greater dry weights, but not soluble carbohydrate concentrations. Regions on chromosomes 5 and 8 showed dominance for increased dry weights or fructans, respectively, but did not interact significantly. A third region on chromosome 3 was previously shown to affect fructan concentrations. Although this region not segregate in this study, the two families were homozygous for contrasting alleles and their genetic backgrounds interacted significantly with regions on chromosomes 5 and 8 to control total carbohydrate concentrations. These results indicate that the ability of onion to accumulate fructans is relatively simply inherited and significantly affected by three chromosome regions.