Comparison of nonstructural carbohydrates across cranberry cultivars

Authors: WASKO DEVETTER, LISA - Washington State University; BEAVER, EMILY - University Of Wisconsin; COLQUHOUN, JED - University Of Wisconsin; Zalapa, Juan; HARBUT, REBECCA - Kwantlen Polytechnic University

Submitted to: European Journal of Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/4/2016
Publication Date: 12/23/2016
Publication URL: https://handle.nal.usda.gov/10113/6472180
Citation: DeVetter, L.W., Beaver, E., Colquhoun, J., Zalapa, J., Harbut, R. 2016. Comparison of nonstructural carbohydrates across cranberry cultivars. European Journal of Horticultural Science. 81(6):321-326. doi: 10.17660/eJHS.2016/81.6.5.

Interpretive Summary: The American cranberry is a woody perennial native to northeastern continental American. Plants are evergreen and produce both low-growing branches and vertical branches, known as uprights. Uprights are either reproductive (fruiting) or vegetative (nonfruiting). Vegetative uprights only produce leaves, whereas fruiting uprights produce flowers and thus have the potential to contribute to next year’s crop. Previous research has demonstrated that individual cranberry uprights exhibit biennial (every other year) bearing tendencies. Specifically, reproductive uprights have a lower probability of developing and setting fruit the following year relative to vegetative uprights. This study evaluated and compared carbohydrate concentrations across cranberry cultivars that differ in biennial bearing tendencies. Vegetative uprights generally had greater concentrations of carbohydrates relative to reproductive uprights, while roots had the lowest concentration across all cultivars. Concentrations of carbohydrates in cranberry reproductive uprights were lowest on 30 July, which corresponds to late bloom/early fruit set and bud development. These findings support the explanation that carbohydrate limitation in reproductive uprights may contribute to biennial bearing by reducing the potential for return bloom. This research contributes to developing better cultivars through breeding for resource allocation for increased return bloom. The return bloom characteristic has the potential to enhance yields by circumventing traditional biennial bearing tendencies. Given the productive capacity of these new cultivars and ability to continuously form reproductive buds, additional evaluations of carbohydrates will provide valuable insight on the physiology of how these plants are able to circumvent traditional biennial bearing tendencies.

Technical Abstract: explain low fruit set and biennial bearing tendencies of cranberry (Vaccinium macrocarpon). Yet, comparisons of nonstructural carbohydrate concentrations during critical phenological stages across cultivars that differ in biennial bearing tendencies and return bloom potential are lacking, particularly among new germplasms. This study sought to address this deficiency by comparing total nonstructural carbohydrates (TNSC), soluble sugars (SS), and starch concentrations across cultivars that reportedly differ in biennial bearing tendencies and return bloom potential. Plant material representing ‘Stevens’, ‘HyRed’, and ‘Gryglesky Hybrid 1’ (‘GH1’) cultivars were collected from a commercial cranberry marsh located in central Wisconsin. Concentrations of sucrose, glucose, fructose, and starch were determined via high-performance liquid chromatography. Patterns of carbohydrate changes were similar to previous reports. Vegetative uprights generally had greater concentrations of carbohydrates relative to reproductive uprights, while roots had the lowest concentration across all cultivars. Concentrations of TNSC and SS in reproductive uprights were lowest on 30 July, which corresponds to late bloom/early fruit set and terminal bud development. ‘Stevens’ and ‘HyRed’ TNSC and SS concentrations subsequently increased after this period, whereas concentrations remained low in ‘GH1’. Return bloom potential was lower in ‘GH1’ relative to ‘Stevens’ and ‘HyRed’. These findings support the explanation that carbohydrate limitation in reproductive uprights may contribute to biennial bearing by reducing the potential for return bloom.