|Vandenlangenberg, Kyle -|
|Nienhuis, James -|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 30, 2012
Publication Date: January 30, 2012
Citation: Vandenlangenberg, K.M., Bethke, P.C., Nienhuis, J. 2012. Identification of quantitative trait loci associated with fructose, glucose and sucrose concentration in snap bean (Phaseolus Vulgaris L.) pods. Crop Science. 52:1593-1599. Interpretive Summary: Consumer demand for a vegetable variety depends, in part, on consumer preference for vegetable flavor. In many cases, vegetables higher in sugars are perceived to taste better than those lower in sugars. Two examples of this are supersweet sweet corn and sugar snap peas. The sugars sucrose, glucose and fructose are found in the pods of snap and dry beans, and the amount of each sugar is genetically controlled. A research study was conducted with the goal of identifying regions of the snap bean DNA that are related to pod sugar content. A single region was identified that has a large affect on pod sucrose, fructose and glucose contents, and a second region was identified that has an additional affect on pod glucose contents. Plant breeders can use the genetic tags linked to these two regions to efficiently develop new bean varieties with improved flavor. This will provide consumers with a better product, and may encourage greater consumption of snap beans as part of a vegetable-rich diet. Increased demand would also benefit bean growers, canners and processors in terms of increased sales and potentially new product offerings.
Technical Abstract: Sugars, including fructose, glucose, and sucrose contribute significantly to the flavor and consumer acceptance of snap beans (Phaseolus vulgaris L.). Differences between dry and snap bean cultivars and among snap bean cultivars in the patterns of accumulation of sugars have been observed. In ‘Eagle’, a white-seeded, large-sieve snap bean cultivar, fructose and glucose concentrations in developing pods decreased while sucrose concentration increased with increasing pod size. In contrast, fructose and glucose concentrations increased while sucrose remained unchanged with increasing pod size in ‘Puebla 152’, a black-seeded dry bean landrace from Mexico. A recombinant inbred line population, derived from the cross ‘Eagle’ x ‘Puebla 152’, consisting of 75 F2:10 recombinant inbred lines (RIL) was developed by single seed descent. Significant differences in fructose, glucose, and sucrose were observed among RILs, with no significant genotype by year interactions. Heritability estimates for fructose, glucose, and sucrose were 0.85, 0.81, and 0.85, respectively. A single QTL was mapped to linkage group B1 and was closely linked to RAPD marker W9.1050 that explained 28.8% of the variation in fructose and 26.6% in sucrose concentration in pods. A two-QTL model, including W9.1050 and F8.500 on linkage group B6 explained 36.4% of the variation in glucose concentration in pods.