( Guner and Wehner, 2004 ; Wehner, 2008a , 2012 ). The rind of watermelon fruit can be striped or solid colored. The solid rind patterns include solid dark green as in ‘Black Diamond’, solid medium green as in ‘Peacock Shipper’, solid light green as in
Lingli Lou and Todd C. Wehner
Shin Hiratsuka, Yuka Yokoyama, Hiroshi Nishimura, Takayuki Miyazaki, and Kazuyoshi Nada
young ‘Valencia' orange ( Citrus sinensis ) fruit; incorporated 14 C was distributed into sugars, amino acids, and organic acids in rind tissues under light conditions, but not into sugars in the juice sacs. In experiments determining the role of fruit
Graham H. Barry and Smit le Roux
Rind color of citrus fruit is an important cosmetic preference of consumers when purchasing citrus fruit who generally prefer a deep orange rind color ( Krajewski, 1997 ). As citrus fruit mature, changes in rind color are the result of decreased
Gabriele Gusmini*, Jonathan Schultheis, and Todd Wehner
Salted or sweet pickles made from the rind of watermelon (Citrullus lanatus) fruit are commonly produced in North America, Europe, and Asia. Among growers and food processors, there is an increasing interest in identifying cultivars suitable for industrial production of watermelon rind pickles. Cultivars for pickling should have a thick, white rind (mesocarp). The objective of our study was to evaluate adapted watermelon cultivars for use in pickling. We measured rind thickness of cultivars in eight North Carolina trials conducted in 1995 to 2002. The top three cultivars for rind thickness (22 to 24 mm) were Jubilee, Arriba and Charleston Gray (seeded), and Fantastik, Sweetheart and Triple Crown (seedless). Cultivars with the thinnest rind (7 to 8 mm) were Emperor, Scarlet Trio, Tri-X-464 and Carnival.
Paul J.R. Cronje, Graham H. Barry, and Marius Huysamer
The citrus fruit is botanically classified as a hesperidium berry and has a leathery rind that is important from a horticultural perspective in that it is essentially this structure that determines the fruit’s commercial value in the fresh fruit
Charles E. Johnson and Blair Buckley
Inheritance of dark green stripe and light green rind color in watermelon was investigated. Controlled crosses were made between watermelon cultivars: `Louisiana Sweet'-light green rind with dark green stripe; `Calhoun Sweet'-dark green rind without stripes; and `Charleston Gray' and `Calhoun Gray' both having light green rind without stripes. Plants of parental, F1, F2, and BC lines were classified as to rind color and presence or absence of stripe. All F1 progenies produced only striped fruit. Chi Square analysis of F2 and BC generations corresponded to 3:1 and 1:1 ratios respectively, for stripe:no stripe, indicating dark green stripe was controlled by one dominant gene. The cross `Louisiana Sweet' × `Calhoun Sweet',(light green × dark green rind color), resulted in F1 and F2 progeny having only dark green rind fruit, indicating obvious dominance for dark green rind color. Segregation in BC populations indicated a single dominant gene for dark green rind color; however, lack of segregation in the F2 suggests additional factors may be involved.
Gabriele Gusmini, Jonathan R. Schultheis, and Todd C. Wehner
Salted and sweet watermelon rind pickles are commonly produced in North America, Europe, and Asia using traditional recipes. Homeowners and small industries use the leftover watermelon crop, especially from cultivars having thick and crisp rind, to produce pickles. Recently, we classified rind thickness for a set of obsolete and heirloom cultivars used by home gardeners and heirloom collectors in the United States. In this study, we used elite cultivars for growers interested in high yield, fruit quality, adaptability, and disease resistance. The objective of this study was to classify modern cultivars (nine inbreds and 103 F1 hybrids) of watermelons available to growers for use in production of watermelon rind pickles. Based on the data, cultivars were divided into three groups of rind thickness and categorized according to pedigree (inbred or F1 hybrid), fruit type (seeded or seedless), and flesh color (red, orange, or yellow). Most of the cultivars tested (109 of 112) had rind thicker than 10 mm and could be used for pickle production.
W.D. Scott and B.D. McCraw
Three cultivars of watermelon (Citrullus lanatus), `Crimson Sweet', `Charleston Gray' and `Tri-X Seedless' were grown in combination with 4 levels of soil applied calcium (0, 280, 560, 1120 kg Ca/ha). Gypsum was incorporated into 6 m plots on 5 m centers then covered with black plastic mulch. Irrigation requirements were provided through a M-wall drip system and soil water status monitored with tensiometers. Transplants were spaced 1.2 m apart in-row spacing allowing for 5 plants per plot and replicated times. Rind tissue from mature watermelon fruit was divided into 4 sections, blossom-end, middle top, grounds spot and stem end. Each section was measured for resistance to shear and puncture by a Model T-1200-G texture and tenderometer system. Thickness was also measured. Lab determinations for total and extractable calcium on the sections was done to determine if there is a relationship between rind resiliency and calcium concentration. Data will be presented et the meeting.
David Obenland and Paul Neipp
Green lemons (Citrus limon (L.) Burm.) were imaged for chlorophyll fluorescence (CF) 30 minutes after immersion of the fruit into 55 °C water for 5 minutes to determine if CF could be used to identify areas of hot water-induced rind injury before the appearance of visible symptoms. Fluorescence was variable in intensity over the surface of the rind with defined areas of enhanced fluorescence being present that corresponded in shape and location with visible injury that later developed during 24 hours of storage. Images showing minimum fluorescence (F0) and maximal fluorescence (Fm) provided the best image contrast between injured and noninjured areas of the rind. Total F0 present in the image was closely correlated (r 2 = 0.87) with the area of rind injury present following storage. Holding the fruit under conditions of low humidity for 24 h before hot water treatment prevented both the formation of areas of enhanced fluorescence and the corresponding rind injury. Imaging of CF has potential as a means to identify areas of incipient rind injury in citrus to facilitate study of the causal mechanisms of postharvest rind disorders.
Noboru Muramatsu, Toshio Takahara, Tatsushi Ogata, and Kiyohide Kojima
Changes in rind firmness and cell wall polysaccharide composition were measured in fruit with a) a soft rind, (`Satsuma' mandarin, Citrus unshiu Marc., cv. Aoshima), and b) a firm rind (hassaku, C. hassaku Hort. ex Tanaka), from August to January of the following year. Rind firmness was similar in both species in August, but hassaku had significantly firmer rind than did mandarin from September to January. Both flavedo and albedo tissues were extracted, and the extracts were hydrolyzed and fractionated to yield four fractions: (hot water, EDTA, hemicellulose, and cellulose). In flavedo tissue, sugar concentration was highest in the cellulose fraction, and lowest in the hemicellulose fraction. The concentration in all fractions decreased as the fruit developed and matured. Although the sugar concentration in the cellulose and EDTA fractions of both species was similar in August, it was significantly higher in both fractions in hassaku than in mandarin in January. The sugar concentration of each fraction from albedo tissue was in the order: cellulose > hemicellulose > hot water > EDTA. The range of variation in cell wall sugars in albedo tissue was smaller than that in flavedo tissue. Chemical name used: ethylenediaminetetraacetic acid (EDTA).