Calcium accumulation in developing cranberry fruit is influenced by fruit cuticle thickness and changes in pedicel xylem

Fruit quality is the main trait of interest in the cranberry (Vaccinium macrocarpon Ait.) industry due to its pivotal role in the production of higher-value products such as sweetened and dried cranberries (SDC). Calcium (Ca) is a key nutrient for fruit quality due to its role bonding with pectin in the middle lamella of the cell wall providing strength through cell-to-cell adhesion, thus increasing fruit firmness and postharvest life.
The objective of this study was to evaluate fruit transpiration, stomatal conductance, cuticle thickness, and pedicel vessel changes during cranberry (Vaccinium macrocarpon Ait.) fruit development and their effect on fruit Ca translocation. ‘Stevens’ cranberry fruits were collected weekly starting at seven days after full bloom (DAFB) until 70 DAFB. For each collection date, fruit transpiration and stomatal conductance were evaluated in the field and samples for total fruit Ca content, stomata number and density, cuticle thickness, pedicel anatomical changes, and xylem functionality were collected for analysis.
Ca accumulated in the fruit following a sigmoidal curve, starting at 0.04 mg per berry at 7 DAFB increasing to a maximum of 0.1 mg per berry at 28 DAFB, and staying constant until harvest (70 DAFB). Fruit Ca accumulation was mostly explained by fruit transpiration, which followed a similar sigmoidal pattern.
The quick decline in fruit transpiration was largely modulated by increases in cuticle thickness, as well as anatomical changes in the pedicel xylem.

XIII International Vaccinium Symposium

P. Rojas-Barros, J. Wernow, B.A. Workmaster, J.M. Devi, A. Atucha

Vaccinium macrocarpon Ait., fruit development, xylem vessel diameter and density

https://doi.org/10.17660/ActaHortic.2025.1440.30