Differences in Cell Number Facilitate Fruit Size Variation in Rabbiteye Blueberry Genotypes

Abstract

<jats:p>Fruit size is a valuable commercial trait in blueberry. The cellular basis of variation in fruit size among rabbiteye blueberry (<jats:italic>Vaccinium ashei</jats:italic>) genotypes was investigated. Twenty genotypes, including cultivars and advanced selections from the University of Georgia blueberry breeding program, were analyzed. Among the 20 genotypes, fruit weight and fruit diameter varied by over threefold and 1.6-fold, respectively. Regression analysis indicated a linear relationship between fruit weight and fruit diameter (<jats:italic>R<jats:sup>2</jats:sup></jats:italic> = 0.97, <jats:italic>P</jats:italic> &lt; 0.001), suggesting that fruit diameter is a good predictor of fruit weight. Among the 20 genotypes, mesocarp cell number and cell area varied by almost 2.5-fold and 1.5-fold, respectively. Although fruit diameter and cell number were significantly related (<jats:italic>R<jats:sup>2</jats:sup></jats:italic> = 0.79, <jats:italic>P</jats:italic> &lt; 0.001), no relationship could be established between fruit diameter and cell area. These data indicate that variation in fruit size among rabbiteye blueberry genotypes is primarily facilitated by variation in cell number. Two small and two large fruit size genotypes were further analyzed. Differences in cell number among some of these genotypes were apparent at bloom suggesting that cell production before bloom is an important mechanism contributing to variation in final cell number. Differences in final cell number among other genotypes were manifested during fruit development, indicating that cell production during fruit development was also instrumental in determining variation in final cell number. This study suggests that fruit size variation in rabbiteye blueberry genotypes is determined by mechanisms that regulate cell production before bloom and during fruit development.</jats:p>

Characterization of Attributes Related to Fruit Size in Pomegranate

“…In a number of cases, fruit size variation has been correlated to differences in cell number of these tissues. Larger-sized fruits were associated with greater mesocarp cell numbers in peach, Prunus persica (Scorza et al, 1991), olive, Olea europaea (Rapoport et al, 2004), sweet cherry, Prunus avium (Olmstead et al, 2007), Saskatoon, Amelanchier alnifolia (McGarry et al, 2001), and rabbiteye blue-berry, Vaccinium ashei (Johnson et al, 2011). In strawberry (Fragaria •ananassa), fruit size was correlated with the number of receptacle cells (Cheng and Breen, 1992).…”

“…Clearly defining the timing of flower initiation and development is warranted as well as studies to determine the effect of variables that affect flower strength and vigor (quality). Flower and/or ovary size have been shown to impact final fruit size in a number of other fruit crops, including peach (Scorza et al, 1991), blueberry (Johnson et al, 2011), and olive (Rosati et al, 2009).…”

Morphological Characterization of Drupes Reveals a Higher Diversity of Phyllanthus emblica Germplasm in Anuradhapura, Kandy and Kurunegala Districts of Sri Lanka

“…It has been reported in early studies that, the increase in cell number of the mesocarp correspond to the increase of drupe size of different cultivars. This phenomenon is true for small and large cultivars of peach (Scorza et al, 1991), sweet cherry Iezzoni, 2007 andZhang et al, 2010) and rabbit eye blueberry (Johnson et al, 2011). But according to the results P. emblica drupe size varies with cell size which is similar to the case of tomatoes.…”

Differences in Softening of ‘Shigyoku’ and ‘Heukboseok’ Grapes during Harvest Period Appears to be Related to Differences of Pedicel Vascular Bundle

“…과실의 크기는 세포 수와 세포 비대에 의하여 결정되며 (Bain and Robertson 1950;Johnson et al, 2011), 복숭아와 올리브의 과실 크기는 세포분열율에 크게 영향을 받는다 (Scorza, 1991;Hammami et al, 2011). 또한 Bain and Robertson(1951) McAtee et al, 2009;Jovyn et al, 2013).…”