sugars and starch, 500-mg fruit samples were collected at harvest time (mature green stage) and ground after lyophilization. A fruit sample subset was allowed to fully ripen (ripened yellow stage) and analyzed for sugars and starch. Soluble sugars were
Ricardo Goenaga, Brian Irish, and Angel Marrero
Melissa Neal and Ellen B. Peffley
Over the past several growing seasons researchers at Texas Tech University have observed that certain onions appeal to rabbits more than other onions, meaning that rabbits tend to nibble on certain lines or varieties and leave other lines undisturbed. We were interested in determining the cahracteristics of the onions that rabbits seemed to like. Onions were planted at random in the TTU breeding nursery. During the growing season all onions were rated for rabbit appeal - those with chewed leaves and or bulbs were recorded as liked by the rabbits. All onions in each plot, whether disturbed or undisturbed by the rabbits, were tested for pyruvate concentration and soluble solids content after harvest. Pyruvates were measured by mmol/gram pyruvic acid and soluble solids content by °Brix refractometer reading. The most damage occurred in onion lines that had the lowest pyruvate levels. Soluble solids did not appear to affect the rabbits' nibbling.
Ya-Ching Chuang and Yao-Chien Alex Chang
The vase life of Eustoma cut flowers can be extended by adding sugars to the vase solution, but the exact role of sugars and how they are translocated in tissues are not clear. Thus, we observed the preserving effect of different sugars in vase solutions on Eustoma and compared sugar concentrations in vase solutions and in the flowers as well as stems and leaves of cut flowers in a solution containing 200 mg·L−1 8-hydroxyquinoline sulfate (8-HQS) with and without 20 g·L−1 sucrose during different flowering stages. Inclusion of glucose, fructose, or sucrose in the vase solution extended the vase life of cut flowers with no significant differences among sugar types. During flower opening, the concentration of added sucrose in the vase solution dropped, and the fresh weight (FW), glucose concentration, and sucrose concentration of flowers in sucrose solutions increased, whereas flowers in solutions without sucrose had lower FW and glucose concentrations. During flower senescence, sugar concentration in the vase solution did not change much, but the FW and sucrose concentrations in all flowers declined, although the FW of sucrose-treated flowers fell more slowly. For stems and leaves in the sucrose solution, sugar concentrations increased during the first 7 days with only glucose slightly declining during senescence, whereas the FW was maintained during the entire vase life. In contrast, FWs of those in the solution without sucrose gradually declined. In conclusion, sucrose in the vase solution promoted flower opening and maintained the water balance of Eustoma cut flowers. Glucose and fructose also extended the vase life, likely in similar ways.
Eulogio Pimienta-Barrios and Park S. Nobel
Flower and fruit production by the columnar cactus, Stenocereus queretaroensis (Weber) Buxbaum, occurred during the dry season in the late winter and spring, and the relatively small annual stem extension occurred primarily during the fall. Thus, reproductive growth does not directly compete with vegetative growth for resources such as reducing sugars, which increased during the wet summer season, a period when total sugars were decreasing. Stem extension, reproductive demography, fruit quality, seed size, and seed quality were not influenced by irrigation. Final fruit size and seed germination, however, were enhanced by applying water. The times from flower bud differentiation to flower opening and from anthesis to fruit ripening were relatively short and unaffected by irrigation.
Ricardo Goenaga, Brian Irish, and Angel Marrero
locations in Puerto Rico. Values are means of six replications and 3 years (2010–13). Table 7. Concentration of starch and soluble sugars at harvest time (mature green) and fully mature (ripened yellow) fruit of ‘FHIA-17’ and ‘Grand Nain’ banana
Lei Gao, Shengjie Zhao, Xuqiang Lu, Nan He, and Wenge Liu
can increase appetite and promote calcium and phosphorus absorption. Different consumers have various preferences for sweet and sour fruit flavor because of dietary changes; when different varieties have a high soluble sugar fruit content, the cultivar
Stacey L. Ontai, Robert E. Paull, and Mikal E. Saltveit Jr.
Sugar peas (Pisum sativum var. saccharatum cv. Manoa Sugar) were stored for 14 or 21 days under controlled atmospheres (CA) of 21% or 2.4% O2, plus 0%, 2.6%, or 4.7% CO2 at 10 or 1C. Changes in appearance, weight, and in the concentrations of chlorophyll, total soluble sugars, insoluble solids, and soluble protein were evaluated before and after storage. After 14 days of storage at 10C there were minor changes in all indicators of quality under the various storage conditions, but the appearance of sugar peas was better under CA than under 21% O2. When quality was evaluated after 21 days, however, storage under CA at 10C was not as beneficial as storage in 21% O2, at 1C. Holding peas in 2.4% O2, for up to 3 weeks at l0C, a higher than recommended storage temperature, maintained better quality than 21% O2. Increasing the CO, concentration from 0% to 2.6% or 4.7% had no adverse effects on quality and had a beneficial effect in some treatments. Compared with storage in 21% O2, the appearance of the peas was better, the concentrations of chlorophyll and soluble sugar were maintained at higher levels, and the insoluble solids were decreased in all atmospheres with 2.4% O2. Appearance and concentrations of chlorophyll, soluble sugars, and proteins were maintained at 1C regardless of treatments.
Michelle R. Botelho and Justine E. Vanden Heuvel
Cranberry production involves the use of flooding for several purposes during the growing season, including pest control, winter protection, and harvest. The effect of the dissolved oxygen concentration in floodwater on carbohydrate concentration of uprights and roots during flooding was investigated using potted `Stevens' cranberry (Vaccinium macrocarpon Ait.) vines. Pots were placed in large bins filled with water to simulate a spring pest control flood (called late water) over a 21-day period. Two treatments were applied: oxygenated and nonoxygenated (control). Uprights and roots were collected every 3 days and prepared for HPLC analysis to quantify nonstructural carbohydrate concentration. Soluble sugar (sucrose, glucose, and fructose) and starch concentration, as well as total nonstructural carbohydrate (TNSC) concentration, decreased over the 3-week period in uprights but not roots regardless of treatment. Interestingly, the sucrose, glucose, fructose, and starch concentrations of uprights in the oxygenated treatment were lower than those of uprights in the control treatment throughout the experiment. This research indicates that vines in flooded bogs demonstrate a net carbon loss, resulting in reduced carbohydrate concentration available for growth and fruit production.
T. Caruso, P. Inglese, M. Sidari, and F. Sottile
Seasonal development of leaf area, leaf area index (LAI), dry matter, and carbohydrate content were measured from harvest 1992 to harvest 1993 in above-ground components of `Flordaprince' peach [Prunus persica (L.) Batsch] trees grafted on GF 677 (Prunus persica × Prunus amygdalus) and MrS 2/5 (Prunus cerasifera free pollinated) rootstocks, which widely differ in vigor. Whole trees were separated into fruit, leaves, shoots, 1-year-old wood and >1-year-old wood. Sampling dates were coincident with key fruit and tree developmental stages: dormancy, fruit set, pit hardening, and fruit harvest. Rootstock modified the vegetative vigor of the tree, the seasonal partitioning of dry matter, and starch content in above-ground components. Leaf area, LAI, and total above-ground dry matter were twice as high in the most vigorous combination (`Flordaprince'/GF 677), which gave the highest yield, but had the lowest harvest index. Rootstock vigor did not affect soluble sugar concentration in any of the canopy components. Starch content was greatest during dormancy and in the oldest wood of GF 677 trees. During fruit development, starch content rapidly decreased in 1-year-old wood and perennial components; at pit hardening it was four times greater in MrS 2/5 than in GF 677 trees. The vegetative-to-fruit dry mass ratio by pit hardening was 3:1 for MrS 2/5 and 9:1 for GF 677 trees. Competition with shoot growth apparently reduced fruit growth, particularly during Stage I and Stage II, as fruit size at harvest was significantly lower (17%) in GF 677 than in MrS 2/5 trees.
Annick Moing, Jean-Luc Poëssel, Laurence Svanella-Dumas, Michèle Loonis, and Jocelyne Kervella
Prunus davidiana (Carr.), a wild species with poor fruit quality that is related to peach [Prunus persica (L.) Batsch], is used as a source of resistance to pests and diseases in peach breeding programs. Two genotypes of P. davidiana were studied for fruit biochemical composition and compared to three genotypes of P. persica (`Summergrand', `Bailey' and `Pamirskij'), and two P. persica × P. davidiana hybrids. Fruit of P. davidiana clones had higher malic acid, neochlorogenic and cryptochlorogenic acid and lower sucrose concentrations than fruit of all P. persica genotypes, even poor-quality Bailey. Differences in biochemical composition could be related to sensory evaluation. P. persica × P. davidiana hybrids had intermediate values between their parents for neochlorogenic acid concentration. They were similar to the P. persica parent for total soluble sugar, malic and citric acid, amino acid and catechin concentrations, indicating possible rapid progress for fruit quality in a breeding program.