scholarly journals Source-Sink Relationships in Cranberry: Effects on Carbohydrate Production and Partitioning

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 761A-761
Author(s):  
Justine E. Vanden Heuvel*
Keyword(s):  
Leaf Area ◽  
Direct Relationship ◽  
Positive Relationship ◽  
Growing Season ◽  
Water Soluble ◽  
Vaccinium Macrocarpon ◽  
Soluble Carbohydrate ◽  
Starch Concentration ◽  
Carbohydrate Concentration ◽  
Source Sink

Fruiting and vegetative greenhouse-grown cranberry uprights (Vaccinium macrocarpon Ait.) were subjected to four defoliation levels (0%, 25%, 50%, 75%) on one of three dates during the growing season. Seven days following defoliation, vines were destructively harvested and carbohydrate concentration was quantified using HPLC. Prior to new growth, defoliation did not affect the concentration of total non-structural carbohydrates (TNSC) in the uprights, or the partitioning of water-soluble (i.e., sucrose, glucose, fructose) to ethanol-insoluble (i.e., starch) carbohydrates, even though uprights with lower leaf areas had higher net CO2 assimilation rates (A). At 2 weeks post-bloom, TNSC concentration was reduced in defoliated vines, although A was not affected by defoliation. Prior to harvest, TNSC concentration was reduced in vines subjected to defoliation while A was unaffected, although the positive relationship between soluble carbohydrate concentration and leaf area per upright reached an asymptote, while the direct relationship between starch concentration and leaf area remained linear. Carbohydrate production and partitioning of an upright was unaffected by the presence of a single fruit throughout the experiment. These results suggest that carbohydrate production in cranberry uprights may be sink-limited prior to fruiting, and then becomes source-limited as the growing season progresses.

Canopy morphology and nutritional quality traits as potential grazing value indicators for Lolium perenne varieties

2002 ◽  
Vol 139 (3) ◽  
pp. 257-273 ◽  
Author(s):  
T. J. GILLILAND ◽  
P. D. BARRETT ◽  
R. L. MANN ◽  
R. E. AGNEW ◽  
A. M. FEARON
Keyword(s):  
Lolium Perenne ◽  
Nutritive Value ◽  
Canopy Structure ◽  
Total Lipid Content ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Carbohydrate Concentration ◽  
Harvest Year ◽  
Water Soluble Carbohydrate ◽  
Testing Protocols

Twelve perennial ryegrass (Lolium perenne L.) varieties of different ploidy and maturity classifications were compared under a frequent cutting management in their second harvest year, equivalent to the simulated rotational grazing system employed in UK testing protocols. Varietal differences in canopy structure (proportion of lamina, green leaf mass, sward surface height, extended tiller height, bulk density) and in herbage nutritive value factors (water-soluble carbohydrate content and proportion of linoleic and α-linolenic fatty acids) were assessed and their importance evaluated with reference to total herbage production. Significant variety variation (P<0·001) was recorded in the annual means of all the canopy structure characteristics. Significant differences associated with ploidy were also recorded, with tetraploid varieties having significantly higher values than diploids in most plant characters, indicating better intake characteristics for these grasses. Temporal patterns of variation associated with maturity were also observed in several characters, thus making it impossible to designate a single assessment that would be representative of the annual ranking of varieties. Water-soluble carbohydrate concentration differed significantly (P<0·001) between varieties and although the tetraploids tended to have high contents, the highest value of all was recorded in a diploid variety, which had been selectively bred for this trait. The varieties did not differ in total lipid content but there were significant differences in the proportion of linoleic acid between varieties (P<0·001) while the proportion of α-linolenic acid differed between varieties (P<0·001), ploidy (P<0·001) and maturity (P<0·05) classes.Overall evaluation of the extensive variety variation highlighted the need for better quantification of animal responses to differences of these magnitudes, before the high workload of including them in routine variety testing protocols could be justified. Potential for breeding improvement in these factors was also indicated and the future prospects for their use in farmer decision support systems was considered.

scholarly journals Additive Type Affects Fermentation, Aerobic Stability and Mycotoxin Formation during Air Exposure of Early-Cut Rye (Secale cereale L.) Silage

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1432
Author(s):  
Horst Auerbach ◽  
Peter Theobald
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Water Soluble ◽  
Potassium Sorbate ◽  
Soluble Carbohydrate ◽  
Chemical Additives ◽  
Air Exposure ◽  
Carbohydrate Concentration ◽  
Aerobic Stability ◽  
Silage Production

Whole-crop rye harvested before maturity represents a valuable forage for silage production. Due to the scarcity of data on fermentation characteristics and aerobic stability (ASTA) and the lack of information on mycotoxin formation during aeration of early-cut rye (ECR) silage after silo opening, we evaluated the effects of different additive types and compositions. Wilted forage was treated with various biological and chemical additives, ensiled in 1.5-L glass jars and stored for 64 days. Fermentation pattern, yeast and mould counts and ASTA were determined at silo opening. In total 34 mycotoxins were analysed in wilted forage and in silage before and after 240 h of air exposure. Chemical additives caused the lowest dry matter (DM) losses during fermentation accompanied with the lowest ethanol production and the highest water-soluble carbohydrate concentration. Aerobic deterioration, which started within two days after silo opening in silage left untreated and inoculated with homofermentative lactic acid bacteria, was prevented by the combined use of hetero- and homofermentative lactic acid bacteria and the chemical additive containing sodium nitrite, hexamethylene tetramine and potassium sorbate. Moreover, these two additives largely restricted the formation of the mycotoxin roquefortine C to < 0.05 mg kg−1 DM after aeration, whereas untreated silage contained 85.2 mg kg−1 DM.

scholarly journals Sucrose Metabolism in Ripening Muskmelon Fruit as Affected by Leaf Area

1990 ◽  
Vol 115 (5) ◽  
pp. 798-802 ◽  
Author(s):  
Natalie L. Hubbard ◽  
D. Mason Pharr ◽  
Steven C. Huber
Keyword(s):  
Leaf Area ◽  
Sucrose Concentration ◽  
Sucrose Phosphate Synthase ◽  
Invertase Activity ◽  
Sugar Accumulation ◽  
Soluble Carbohydrate ◽  
Sucrose Accumulation ◽  
Canopy Photosynthesis ◽  
Carbohydrate Concentration ◽  
Sucrose Metabolizing Enzymes

Muskmelon (Cucumis melo L.) fruit lack a stored starch reserve and therefore depend on translocated photoassimilate from the leaf canopy for sugar accumulation during ripening. The influence of canopy photosynthesis on sucrose' accumulation within muskmelon fruit mesocarp was examined. Canopy photosynthetic activities were estimated in a sweet and a nonsweet genotype. Photosynthetic rate of the nonsweet genotype, on a per-plant basis, was only 56% of that of the sweet genotype. The effect of limiting leaf area of the sweet genotype on carbohydrate concentrations and sucrose metabolizing enzymes within the fruit was evaluated. A 50% reduction of leaf area 8 days before initiation of fruit sucrose accumulation resulted in canopy photosynthesis similar to that of the nonsweet genotype. Reduced photosynthetic activity resulted in slightly lower soluble-carbohydrate concentration in the fruit; however, fruit sucrose concentration was three times higher than that reported previously for the nonsweet genotype. The extent to which `fruit sucrose phosphate synthase (SPS) activity increased during maturation was diminished by leaf removal. Acid invertase activity declined in all fruit in a similar manner irrespective of defoliation. A reduction of leaf area of a sweet genotype reduced sucrose accumulation within the fruit. Lower fruit sucrose concentration was associated with lower concentration of raffinose saccharides and lower SPS activity within the fruit. Additionally, insufficient assimilate supply was judged not to be the factor responsible for low sucrose accumulation in a nonsweet genotype.

scholarly journals SEASONAL CHANGES IN NONSTRUCTURAL CARBOHYDRATES IN CRANBERRY

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1066f-1066
Author(s):  
Teryl R. Roper ◽  
Marianna Hagidimitriou
Keyword(s):  
Seasonal Changes ◽  
Fruit Set ◽  
Starch Content ◽  
Yield Component ◽  
Vaccinium Macrocarpon ◽  
Soluble Carbohydrate ◽  
Limiting Factor ◽  
Flower Initiation ◽  
Nonstructural Carbohydrates ◽  
Carbohydrate Concentration

Carbohydrate concentration may be important for flower initiation and fruit set in cranberry (Vaccinium macrocarpon Ait.). Fruit set has been shown to be a major limiting factor in yield component analysis. The objective of this research was to identify carbohydrate concentrations in cranberry tissues at various stages of development under field conditions. Samples of two cranberry cultivars, `Stevens' and `Searles' were collected during the 1989 season using a 13 cm diameter probe. Samples were divided into fruit, uprights, woody stems and roots. Carbohydrates were quantified by HPLC. Nonstructural carbohydrates were primarily sucrose, glucose, fructose and starch. Soluble carbohydrate concentration was stable throughout the season in tissues analyzed, while starch content was high early in the season then decreased during blossom and fruit set. This work shows that starch reserves in leaves and stems apparently are remobilized to support fruit set in cranberry.

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