The shape of ‘Redblush’ grapefruit, Citrus paradisi Macf., grown in controlled environments was affected by the difference between day and night temperature. Fruit grown under a 32°/30°C day/night temperature regime had creased stem ends; a 32°/24° regime resulted in normal fruit, and 32°/7° induced severe sheepnosing. Reducing daylength from 14 to 11 hours had no influence on fruit shape.
, personal communication). This elongated fruit shape trait has remained in the Arkansas grape breeding program and subsequent crosses have been made to further express this trait. No elongated cultivars have been released, but in the growing area of
The climate where fruit is grown can affect many different aspects of growth and development, including shape. Several reports have been published for fruit other than peaches concerning climatic and temperature effects on fruit shape. In general
The domestication and breeding of cultivated tomato ( Solanum lycopersicum L.) resulted in a diverse collection of varieties that differ in fruit shape and size ( Paran and van der Knaap, 2007 ). Tomato is an excellent model to use to gain
Quantifying fruit shape is challenging, particularly when measurements are made on segregating populations of plants that vary greatly in shape. Objective manual measurements can be performed on small samples of fruit, but this method is not feasible when dealing with larger samples or when shape variations are slight and continuous. Also, subjective rating scales can be utilized, but they are less effective when done by multiple raters due to varying descriptive standards among individuals. Therefore, we have developed a method to analyze digital images containing multiple fruits to characterize fruit shapes. Each segregant of a population of table grapes with parents of significant varying shapes was photographed and analyzed. Image pixels representing fruit were selected and evaluated for area and perimeter, which were subsequently used to calculate a shape factor and compactness value. This was a reasonably simple and quick method for quantifying grape berry shape, giving the researcher valuable phenotypic data in numerical form. This technology should be useful for shape characterizations of other fruits as well.
Mild winter weather conditions reduce fruit yield and quality of many peach cultivars grown in the Medium Chill Region of the United States. Peach fruit shape instability limits marketing options for growers in this region. The Stonefruit Breeding Program at Texas A&M University evaluated a wide range of peach cultivars and breeder selections from throughout the world during the mild winters of 1988-198 9 and 1989-1990. Fruit shape response was highly variable among genotypes with similar chilling requirements. The implication of this is that the potential is high for eliminating fruit shape instability due to highly variable winter conditions in the Medium Chill Peach Production Region.
The relations between peel thickness and fruit shape of ‘Marsh Seedless’ grapefruit and various climatic factors were studied at 8 locations in Israel. Peel thickness was affected greatest by winter temp. Low winter temp resulted in fruits with thick peel in the following year. Fruit shape was affected to a similar degree by low winter temp, summer air humidity, and rate of evaporation. Summer temp and the differences between maximum and minimum temp in the spring and fall, had little effect on fruit shape and peel thickness.
(2-Chloroethyl)phosphonic acid (ethephon) applied to ‘Delicious’ apples before harvest to improve fruit quality can change fruit shape (length/diameter ratio) the next year. The change is magnified when ethephon follows a summer application of succinic acid-2,2-dhnethylhydrazide (SADH) and is most evident on low vigor trees.
Considerable work has been done on the effects of gibberellins on parthenocarpic set and growth of apple fruits. Bukovac (1) has reviewed the literature in this field and has presented further evidence that seedless fruits induced to set by gibberellins A3 and A4 (GA3 and GA4) are distinctly more elongate than normal seeded fruits. More recently Dennis and Edgerton (2) found that GA made seeded fruits of one variety of apple more elongate than controls, although shape was not altered on several other varieties. Westwood and Blaney (6) reported several factors other than applied GA that also affected apple shape. Among these were crop density (i.e. leaf: fruit ratio), varietal strain, cluster position, and rootstock. To further study the effect of GA on fruit shape without confounding it with seedlessness, a test was set up using seeded fruits in which crop density and rootstock were held constant.
variability in fruit shape, ranging from elongated, conical, bell and round, to pumpkin-shaped in chile pepper genotypes from the Balkan region of Europe. In another study, fruits of C. chinense genotypes from Brazil were described to be elongated, blocky
