scholarly journals Changes in Polyamine Levels in Relationship to the Double-sigmoidal Growth Curve of Peaches

1998 ◽  
Vol 123 (6) ◽  
pp. 950-955 ◽  
Author(s):  
Mosbah M. Kushad
Keyword(s):  
Fruit Development ◽  
Prunus Persica ◽  
Fresh Mass ◽  
Biosynthetic Enzymes ◽  
Related Phenomenon ◽  
Full Bloom ◽  
Flower Buds ◽  
Flower Bud ◽  
Fruit Maturity ◽  
Seed Growth

Polyamines and the activities of their biosynthetic enzymes were evaluated during peach (Prunus persica L. `Biscoe') mesocarp (pulp) and seed growth starting at full bloom and until full fruit maturity at 14 weeks after full bloom (AFB). Mesocarp fresh mass exhibited a double-sigmoidal pattern characteristic of peaches. Seed fresh mass increased to a maximum of≈1 g at 4 weeks AFB then remained unchanged during the remaining weeks of sampling. Free putrescine, spermidine, and spermine levels were significantly higher in the flower bud, declined in the mesocarp tissue during the first 2 weeks AFB, then exhibited another increase between 2 and 6 weeks AFB. In contrast, conjugated spermidine and spermine levels were low in flower buds, then increased to their maximum level at 6 weeks AFB, then declined at full fruit development. Ornithine decarboxylase (ODC, EC 4.1.1.17) activity was high in flower buds (89.3 nmol·h-1·mg-1 protein) and in early stages of mesocarp development then declined to its lowest level (5.8 nmol·h-1·mg-1 protein) at full-fruit development. Arginine decarboxylase (ADC, 4.1.1.19) activity did not change during the first 6 weeks of mesocarp growth but declined later, reaching its lowest (1.95 nmol·h-1·mg-1 protein) at 14 weeks AFB. During the first 5 weeks AFB, ODC activity was 3.0- to 4.5-fold that of ADC activity; however, at full-fruit maturity (14 weeks AFB) the activities of both enzymes were similar. The slowdown in mesocarp growth during pit hardening between 6 and 9 weeks AFB did not change polyamines concentrations or their biosynthetic enzymes. Free spermidine and spermine levels declined during seed development; however, between 7 and 9 weeks AFB an increase in putrescine was observed. Similarly, conjugated putrescine increased substantially during seed growth reaching its highest level of 680 nmol·g-1 fresh mass at week 8 then declined at the later weeks, while conjugated spermidine and spermine peaked at week 10 to 1,169 and 2,148 nmol·g-1 fresh mass. ODC and ADC activities declined between 3 and 5 weeks AFB. However, a significant increase in ADC but not ODC activity in the seed tissue was observed during pit hardening between 6 and 10 weeks AFB. Based on the rapid increase in putrescine and ADC activity in the seed tissue, it appears that pit hardening may be a stress-related phenomenon. Data also suggest that polyamine levels in the mesocarp and seed tissue are independently regulated.

scholarly journals Flower Bud Load Influences Blueberry Vegetative and Fruit Development

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 682e-682
Author(s):  
B.E. Maust ◽  
J.G. Williamson ◽  
R.L. Darnell
Keyword(s):  
Leaf Area ◽  
Fruit Development ◽  
Reproductive Development ◽  
Dry Weight ◽  
Highbush Blueberry ◽  
Fresh Weight ◽  
Flower Buds ◽  
Flower Bud ◽  
Fruit Maturity ◽  
Southern Highbush

A field experiment was conducted in Gainesville, Fla., with two southern highbush blueberry cultivars, `Misty' and `Sharpblue', to investigate the influence of varying flower bud load on the timing and extent of vegetative and reproductive development. Flower bud load was adjusted on three different canes on ten plants by removing none, one-third, or two-thirds of the flower buds. Vegetative budbreak, leaf area, fruit number, and fruit fresh weight and dry weight were measured. Vegetative budbreak was delayed with increasing flower bud load. Vegetative budbreak, leaf area, and leaf area: fruit ratio decreased with increasing flower bud load. Fruit maturity was delayed and average berry fresh weight and dry weight declined with decreasing leaf area:fruit ratio. Responses were similar for both cultivars although `Misty' was more adversely affected by high flower bud load and low leaf area: fruit ratio.

scholarly journals Fruit Maturity and Calcium Affect Chilling Requirements and Ripening of `d'Anjou' Pears

HortScience ◽  
1997 ◽  
Vol 32 (5) ◽  
pp. 911-913 ◽  
Author(s):  
D. Gerasopoulos ◽  
D.G. Richardson
Keyword(s):  
Fruit Development ◽  
Pyrus Communis ◽  
Fresh Mass ◽  
Chilling Requirement ◽  
Full Bloom ◽  
Immature Fruit ◽  
Flesh Firmness ◽  
Chilling Requirements ◽  
Fruit Maturity ◽  
Mass Basis

`D'Anjou' pear (Pyrus communis L.) trees were sprayed with zero or 32.3 mm CaCl2 during fruit development at 55, 86, 125, and 137 d from full bloom and harvested at 85% (immature), 100% (mature), and 110% (overmature) maturity stages. The fruit were stored in air at –1 °C for several periods to determine the effect of CaCl2 treatments on chilling requirement to accomplish ripening during 11 d at 20 °C. Immature or mature unsprayed fruit required 55 d, while the overmature fruit required 40 d at –1 °C to gain the capacity to produce ethylene during ripening at 20 °C. Calcium sprays increased flesh firmness at harvest by 15 N, fruit Ca concentrations by an average of 0.01 mg·g-1, fresh mass basis, and the chilling requirements by at least 15 d. Unsprayed immature fruit contained more Ca than the sprayed mature or overmature fruit, but their chilling requirement was similar. These results suggest that high Ca concentrations may increase the chilling requirement of `d'Anjou' pears in a developmentally related manner.

scholarly journals Applying Soybean Oil to Dormant Peach Trees Thins Flower Buds

HortScience ◽  
2000 ◽  
Vol 35 (4) ◽  
pp. 615-619 ◽  
Author(s):  
Dennis E. Deyton ◽  
Renae E. Moran ◽  
Carl E. Sams ◽  
John C. Cummins
Keyword(s):  
Soybean Oil ◽  
Prunus Persica ◽  
Flower Buds ◽  
Flower Bud ◽  
Spring Frost ◽  
Fruit Maturity ◽  
Peach Trees

Applications of soybean oil to dormant peach [Prunus persica (L.) Batsch] trees were tested for prebloom thinning of flower buds in five separate experiments. Data were combined from experiments in which 2.5% to 20% emulsified soybean oil was sprayed on `Belle of Georgia' or `Redhaven' trees. The number of dead flower buds was concentration-dependent with maximum bud kill of 53% occurring with application of 12% soybean oil. The amount of thinning was fairly consistent from year to year, ranging from 34% to 51% when 10% soybean oil was applied, but was less consistent when 5% was applied, ranging from 6% to 40%. Overthinning by midwinter applications of soybean oil occurred in one experiment when bud mortality on nontreated trees was 40% due to natural causes. Mild to moderate spring freezes occurred in three experiments, but did not reduce yield more in soybean oil–thinned than in nontreated trees. Flower bud survival was improved when trees were sprayed with 10% or 12% soybean oil prior to a –4 °C spring frost. Applications of soybean oil to dormant trees thinned flower buds, reduced the amount of hand thinning required, and hastened fruit maturity.

scholarly journals 614 PB 290 FLOWER BUD POSITION DETERMINES BLOOM AND FRUIT CHARACTERISTICS IN `ROME BEAUTY' APPLE

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 520b-520
Author(s):  
Randy R. Lee ◽  
John K. Fellman ◽  
Esmaeil Fallahi
Keyword(s):  
Fruit Quality ◽  
Titratable Acidity ◽  
Soluble Solids ◽  
Flower Buds ◽  
Flower Bud ◽  
Terminal Flower ◽  
Fruit Maturity ◽  
Lateral Bud ◽  
Bud Position ◽  
Lateral Flower

The influence of flower bud position on bloom, fruit quality, and fruit maturity was investigated on `Rome Beauty' apple (Malus domestica Borkh.). Limbs on trees containing spur terminal flower buds and lateral flower buds were tagged and the number of blossoms counted every three days until bloom ended. At harvest, fruit from each bud type were selected and seed number, fresh weight, fruit quality characteristics, and onset of ethylene production were measured. Spur terminal flower buds began blooming earlier, blossomed for a longer period of time, and produced more blossoms than lateral flower buds. Fruit from spur terminal flower buds had more seeds, were heavier, and contained more starch than lateral bud fruit. Lateral bud fruit had higher pressure values, due to smaller size, and higher soluble solids, due to consumption of starch reserves. Fruit color and titratable acidity were not significantly different regardless of bud position. Spur terminal fruit started producing ethylene eight days later than lateral bud fruit, indicating they were maturing less quickly. Cultivars such as `Fuji', `Gala', and `Braeburn' display similar growth and fruiting habits.

scholarly journals 758 PB 158 COMPARISON OF SEASONAL PATTERNS OF POLYAMINES DURING FRUIT AND SEED GROWTH OF PEACHES

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 541f-541
Author(s):  
Mosbah M. Kushad
Keyword(s):  
Seasonal Variation ◽  
Fruit Development ◽  
Prunus Persica ◽  
Fruit Set ◽  
Ethylene Biosynthesis ◽  
Seasonal Patterns ◽  
Flesh Color ◽  
Fruit Development And Ripening ◽  
Seed Growth ◽  
The Relationship

Seasonal variation in polyamines were evaluate during growth of fruit and seed of peach (Prunus persica L. cvs. Loring and Biscoe) starting at fruit set. In both cultivars, putrescine and spermidine increase significantly while spermine increase only slightly during the early stages of development then declined at the later stages. During pit hardening, polyamines in the flesh remained unchanged but their level in the seed continued to decrease. In both cultivars, polyamine levels corresponded to changes in fruit and seed sizes. when polyamines were vacuum infiltrated into commercially mature Biscoe fruits, flesh firmness, ethylene biosynthesis, and flesh color were significantly different from untreated tissue. The relationship between polyamines, seed development, and fruit development and ripening will be examined.

scholarly journals Flower Bud Density Affects Vegetative and Fruit Development in Field-grown Southern Highbush Blueberry

HortScience ◽  
1999 ◽  
Vol 34 (4) ◽  
pp. 607-610 ◽  
Author(s):  
B.E. Maust ◽  
J.G. Williamson ◽  
R.L. Darnell
Keyword(s):  
Leaf Area ◽  
Fruit Development ◽  
Fruit Size ◽  
Dry Weight ◽  
Vaccinium Corymbosum ◽  
Soluble Solids ◽  
Highbush Blueberry ◽  
Flower Buds ◽  
Flower Bud ◽  
Southern Highbush

Floral budbreak and fruit set in many southern highbush blueberry (SHB) cultivars (hybrids of Vaccinium corymbosum L. with other species of Vaccinium) begin prior to vegetative budbreak. Experiments were conducted with two SHB cultivars, `Misty' and `Sharpblue', to test the hypothesis that initial flower bud density (flower buds/m cane length) affects vegetative budbreak and shoot development, which in turn affect fruit development. Flower bud density of field-grown plants was adjusted in two nonconsecutive years by removing none, one-third, or two-thirds of the flower buds during dormancy. Vegetative budbreak, new shoot dry weight, leaf area, and leaf area: fruit ratios decreased with increasing flower bud density in both cultivars. Average fruit fresh weight and fruit soluble solids decreased in both cultivars, and fruit ripening was delayed in `Misty' as leaf area: fruit ratios decreased. This study indicates that because of the inverse relationship between flower bud density and canopy establishment, decreasing the density of flower buds in SHB will increase fruit size and quality and hasten ripening.

scholarly journals Hydrogen Cyanamide Stimulates Early Foliation of `Misty' Southern Highbush Blueberry

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 537C-537
Author(s):  
J.G. Williamson ◽  
R.L. Darnell
Keyword(s):  
Vegetative Growth ◽  
Fruit Set ◽  
Small Diameter ◽  
Highbush Blueberry ◽  
Full Bloom ◽  
Flower Buds ◽  
Flower Bud ◽  
Hydrogen Cyanamide ◽  
Southern Highbush ◽  
Chilling Treatment

Two-year-old, container-grown `Misty' southern highbush blueberry plants were sprayed to drip with two concentrations of hydrogen cyanamide (HCN) (20.4 g·L–1 and 10.2 g·L–1) after exposure to 0, 150, or 300 hr of continuous chilling at 5.6°C. All plants were sprayed immediately after chilling and placed in a greenhouse for several weeks. The plants were moved outdoors during flowering to increase cross-pollination from nearby `Sharpblue' blueberry plants. HCN sprays killed some of the more advanced flower buds on shoot terminals and on small-diameter wood from the previous spring growth flush. Significantly greater flower bud mortality occurred for the 20.4 g·L–1 HCN sprays than for the 10.2 g·L–1 sprays. Flower buds subjected to 0 hr of chilling were more susceptible to spray burn than flower buds receiving 150 or 300 hr of chilling. Very little flower bud death occurred with the 10.2 g·L–1 HCN rate on plants receiving 300 hr of chilling. Vegetative budbreak was advanced for both HCN treatments compared to controls, regardless of chilling treatment. HCN-treated plants were heavily foliated at full bloom, while non-treated plants had very few to no leaves during bloom. HCN may be useful for stimulating vegetative growth in some southern highbush blueberry cultivars that suffer from poor foliation during flowering and fruit set.

scholarly journals Influence of Blossom and Fruit Thinning on Peach Flower Bud Tolerance to an Early Spring Freeze

HortScience ◽  
1994 ◽  
Vol 29 (3) ◽  
pp. 146-148 ◽  
Author(s):  
Ross E. Byers ◽  
R.P. Marini
Keyword(s):  
Prunus Persica ◽  
Fruit Set ◽  
Unit Length ◽  
Early Spring ◽  
Late Winter ◽  
Flower Buds ◽  
Flower Bud ◽  
Cross Sectional ◽  
Fruit Thinning ◽  
Crop Density

Peach trees [Prunus persica (L.) BatSch.] blossom-thinned by hand were overthinned due to poor fruit set of the remaining flowers; however, their yield was equivalent to trees hand-thinned 38 or 68 days after full bloom (AFB). Blossom-thinned trees had three times the number of flower buds per unit length of shoot and had more than two times the percentage of live buds after a March freeze that had occurred at early bud swell the following spring. Blossom-thinned trees were more vigorous; their pruning weight increased 45%. For blossom-thinned trees, the number of flowers per square centimeter limb cross-sectional area (CSA) was two times that of hand-thinned trees and four times that of the control trees for the next season. Fruit set of blossom-thinned trees was increased four times. Flower buds on the bottom half of shoots on blossom-thinned trees were more cold tolerant than when hand-thinned 68 days AFB. Fruit set per square centimeter limb CSA was 400% greater the following year on blossom-thinned trees compared to controls. Removing strong upright shoots on scaffold limbs and at renewal points early in their development decreased dormant pruning time and weight and increased red pigmentation of fruit at the second picking. The number of flower buds per unit shoot length and percent live buds after the spring freeze were negatively related to crop density the previous season for trees that had been hand-thinned to varying crop densities at 48 days AFB. According to these results, blossom thinning and fruit thinning to moderate crop densities can influence the cold tolerance of peach flower buds in late winter.

scholarly journals Water Stress Alter Leaf Hydric Status and Flower Bud Development in Apricot cv. “Royal”

2020 ◽  
pp. 10-19
Author(s):  
H. Ramírez ◽  
A. I. Melendres- Alvarez ◽  
A. Zermeño- González ◽  
D. Jasso- Cantú ◽  
J. A. Villarreal- Quintanilla
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Late Summer ◽  
Leaf Water ◽  
Full Bloom ◽  
Flower Buds ◽  
Flower Bud ◽  
Bud Development ◽  
Flower Bud Development

Aims: The apricot (Prunus armeniaca L.), is a drought-sensitive deciduous fruit. This concept arises from the fact that soil moisture stress can: Decrease the number and quality of flower buds differentiated; delay the time of flower differentiation and decrease the number of flower buds per shoot. The objectives of this investigation were to determine: The extent to which drought influences water status in the leaves; its effect on flower buds development and on bloom in apricot cv. “Royal”. Study Design: Trees were divided into 6 groups of six replicate each under a random block design. Results were analyzed using the statistical program 'RStudio' for Windows version 10 and data obtained subjected to a comparison of means with the Tukey (P≤0.05) test. Place and Duration of Study: The experiment was conducted at the Department of Horticulture in Universidad Autónoma Agraria Antonio Narro, Saltillo, Mexico, during 2018-2019. Methodology: Seven-year-old apricot trees growing in containers were subjected to a 4 to 5week period of water stress at different times during the growing season. Leaf water potential was periodically measured and flower bud development was followed from early differentiation up to full bloom. Results: Leaf water potential in water stressed trees was constantly low. Water stress early in the season induced a delay in bud development during late summer and fall. Water stress late in the season did not appreciably affect the rate of bud development. Full bloom was delayed when water stress was applied in late summer and fall. Water stress at flower bud initiation and differentiation, together with high temperatures, may have induced flowers with double pistils. Water stress from April through October did not induce flower drop. Conclusion: Soil water stress severely affect leaf water potential; delays flower bud development and may induce flowers with double pistils without flower drop.

scholarly journals Ethephon Prolongs Dormancy and Enhances Supercooling in Peach Flower Buds

1991 ◽  
Vol 116 (3) ◽  
pp. 500-506 ◽  
Author(s):  
Edward F. Durner ◽  
Thomas J. Gianfagna
Keyword(s):  
Prunus Persica ◽  
Storage Period ◽  
Bud Dormancy ◽  
Late Winter ◽  
Flower Buds ◽  
Flower Bud ◽  
Ethephon Treatment ◽  
Bud Growth ◽  
Peach Trees ◽  
Heat Requirement

The heat requirement for flower bud growth of container-grown peach trees [Prunus persica (L.) Batsch. cvs. Redhaven and Springold] in the greenhouse varied inversely and linearly with the length of the cold-storage period (SC) provided to break bud dormancy. Ethephon reduced the rest-breaking effectiveness of the 5C treatment. Buds from ethephon-treated trees grew more slowly than buds from untreated trees upon exposure to 20 to 25C, resulting in later bloom dates. The effect of ethephon on flower bud hardiness in field-grown trees of `Jerseydawn' and `Jerseyglo' was studied using exotherm analysis after deacclimation treatments. Bud deacclimation varied with reacclimating temperature (7 or 21 C), cultivar, ethephon treatment, and sampling date. All buds were more susceptible to injury in March than in January or February. Buds reacclimated more rapidly at 21C than at 7C. `Jerseyglo' reacclimated more rapidly than `Jerseydawn'. Untreated buds were less hardy and also reacclimated more rapidly than treated buds. Ethephon enhanced flower bud hardiness in three distinct ways: 1) it decreased the mean low-temperature exotherm of pistils, 2) it increased the number of buds that supercooled after exposure to reacclimating temperatures, and 3) it decreased the rate of deacclimation, especially at 21C. Ethephon prolongs flower bud dormancy by increasing the chilling requirement. The rate at which flower buds become increasingly sensitive to moderate temperatures in late winter and spring is thus reduced by ethephon. Thus, ethephon delays deacclimation during winter and delays bloom in the spring. Chemical name used: (2-chloroethyl) phosphoric acid (ethephon).

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