scholarly journals 191 SEASONAL VARIATION IN THE RESPONSE OF ENDODORMANT PEACH TO BIOREGULATORS AND THEIR INTERACTION WITH ETHYLENE

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 456d-456
Author(s):  
William C. Mitchell ◽  
Gregory A. Lang
Keyword(s):  
Seasonal Variation ◽  
Prunus Persica ◽  
Tap Water ◽  
Dormancy Breaking ◽  
Hydrogen Cyanamide ◽  
Silver Thiosulfate ◽  
Cu Accumulation ◽  
Temperature Regimes ◽  
Growth Chambers ◽  
Fall Application

Fall application of 2-chloroethylphosphoric acid (ethephon) is known to delay spring budbreak in peach (Prunus persica). To study seasonal variation in peach response to dormancy-breaking plant bioregulators and their possible interaction with ethylene, peach shoots were cut in the field at various intervals during endodormancy. Shoots were dipped in the dormancy-breaking bioregulators hydrogen cyanamide (H2CN2, 100 mM) or gibberellic acid (KGA3, 130 μm), alone or in combination with 1.38 mM ethephon. Treated shoots were held in beakers of either tap water or 1 mM silver thiosulfate (STS), and placed in growth chambers with potassium permanganate traps, 12/12 h photoperiods and 21/26 C temperature regimes. Dormancy-breaking efficacy (apical budbreak at 21 days) of both bioregulators increased as endodormancy progressed. At all intervals, H2CN2, broke dormancy more effectively than KGA3. The addition of ethephon to H2CN2 application prior to any CU accumulation (20 Oct) had no effect on efficacy (80% budbreak), but its addition after accumulation of ∼50 CU (8 Nov) or ∼320 CU (14 Dec) reduced subsequent budbreak to 25% and 40%, respectively. The addition of ethephon to KGA3 applications reduced budbreak both prior to (27 Oct) and after (8 Nov) initial CU accumulation. STS in the beaker solution increased both the extent (27 Oct) and the rate (14 Dec) of KGA-induced budbreak The interaction of ethylene, bioregulator type, and endodormancy regulation will be discussed.

scholarly journals Transcriptomic Study of Early Responses to the Bud Dormancy-breaking Agent Hydrogen Cyanamide in ‘TropicBeauty’ Peach

2019 ◽  
Vol 144 (4) ◽  
pp. 244-256 ◽  
Author(s):  
Lisa Tang ◽  
Shweta Chhajed ◽  
Tripti Vashisth ◽  
Mercy A. Olmstead ◽  
James W. Olmstead ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Wall ◽  
Prunus Persica ◽  
Cell Activity ◽  
Pentose Phosphate ◽  
Bud Dormancy ◽  
Sequencing Analysis ◽  
Dormancy Breaking ◽  
Ros Scavenging ◽  
Hydrogen Cyanamide

To determine how the dormancy-breaking agent hydrogen cyanamide (HC) advances budbreak in peach (Prunus persica), this study compared the transcriptome of buds of low-chill ‘TropicBeauty’ peach trees treated with 1% (v/v) HC and that of nontreated trees at 3 and 7 days after treatment (DAT), respectively, using an RNA sequencing analysis. The peak of total budbreak occurred 6 weeks earlier in the HC-treated trees (at 32 DAT) than the nontreated trees (at 74 DAT). There were 1312 and 1095 differentially expressed genes (DEGs) at 3 and 7 DAT, respectively. At 3 DAT, DEGs related to oxidative stress, including the response to hypoxia, lipid oxidation, and reactive oxygen species (ROS) metabolic process, were upregulated in HC-treated buds. Additionally, DEGs encoding enzymes for ROS scavenging and the pentose phosphate pathway were upregulated at 3 DAT but they were not differently expressed at 7 DAT, indicating a temporary demand for defense mechanisms against HC-triggered oxidative stress. Upregulation of DEGs for cell division and development at 7 DAT, which were downregulated at 3 DAT, suggests that cell activity was initially suppressed but was enhanced within 7 DAT. At 7 DAT, DEGs related to cell wall degradation and modification were upregulated, which was possibly responsible for the burst of buds. The results of this study strongly suggest that HC induces transient oxidative stress shortly after application, leading to the release of bud dormancy and, subsequently, causing an increase in cell activity and cell wall loosening, thereby accelerating budbreak in peach.

Dormancy-breaking Studies on Echinacea angustifolia

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 456f-457 ◽  
Author(s):  
Ali O. Sari ◽  
Mario R. Morales ◽  
James E. Simon
Keyword(s):  
Native Americans ◽  
Seed Germination ◽  
Tap Water ◽  
The United States ◽  
Market Demand ◽  
Dormancy Breaking ◽  
Echinacea Angustifolia ◽  
Native Populations ◽  
Percent Germination ◽  
Dry Heating

Echinacea is a medicinal plant native to North America. It was used extensively by native Americans in the treatment of their ailments. It is presently one of the most popular medicinal plants in the United States. Its popularity has created a large market demand for the roots and foliage of the plant. The gathering of echinacea from the wild is leading to the reduction of native populations and the destruction of its genetic diversity. Cultivation of medicinal echinaceas is hindered by a low seed germination. Dormancy breaking studies were done on freshly harvested seeds of Echinacea angustifolia. Seed lots were placed under light at a constant temperature of 25 °C and at alternate temperatures of 25/15 °C for 14/10 h, respectively. Germination was more rapid and uniform and percent germination higher at 25 °C than at 25/15 °C. Seed tap-water soaking, dry heating, and sharp heating alteration did not increase germination. The application of 1.0 mM ethephon (2-chloroethylphosphoric acid) increased seed germination to 94% at 25 °C and 86% at 25/15 °C. Untreated seeds gave 65% germination at 25 °C and 11% at 25/15 °C. The application of 2500 mg·L–1 and 3500 mg·L–1 of GA to dry seeds and 2500 mg·L–1 to seeds that have been soaked under tap water and then dried increased germination to 82%, 83%, and 83% at 25 °C and 64%, 78%, and 64% at 25/15 °C, respectively.

Seasonal Neonatal Hyperbilirubinemia

PEDIATRICS ◽  
1969 ◽  
Vol 43 (4) ◽  
pp. 601-605
Author(s):  
Thomas H. Milby ◽  
James E. Mitchell ◽  
Thomas S. Freeman
Keyword(s):  
Seasonal Variation ◽  
Bilirubin Level ◽  
Tap Water ◽  
Neonatal Hyperbilirubinemia ◽  
Unconjugated Bilirubin ◽  
Hemolytic Disease ◽  
Local Hospital ◽  
Unconjugated Hyperbilirubinemia ◽  
Clear Cut ◽  
Agricultural Community

A seasonal variation in the incidence of neonatal nonhemolytic, unconjugated hyperbilirubinemia has been observed in a small, predominantly agricultural community. A total of 3,096 records, representing all newborns delivered during a 4-year period (1963-1966) in one local hospital and during an overlapping 3-year period (1964-1966) in another, were reviewed. A case was defined as an infant whose highest recorded unconjugated bilirubin level reached 10 mg/100 ml during the first days of life. Infants with clear-cut hemolytic disease of the newborn were excluded from consideration. One hundred seventy cases were identifled. In one hospital, an excess of cases occurred during the fourth quarter of each of the 4 years reviewed. A similar trend was apparent in the second hospital during 2 of the 3 years reviewed. The cause of this systematic fluctuation is unclear. Insofar as possible, factors commonly associated with neonatal hyperbilirubinemia were excluded. During the peak incidence penods, a surplus of cases among infants fed with tap water-containing formula was noted.

Inter- and intra-varietal variation in aerobic methane emissions from environmentally stressed pea plants

Botany ◽  
2018 ◽  
Vol 96 (12) ◽  
pp. 837-850 ◽  
Author(s):  
Awatif M. Abdulmajeed ◽  
Mohammad I. Abo Gamar ◽  
Mirwais M. Qaderi
Keyword(s):  
Stress Factors ◽  
Interactive Effects ◽  
Controlled Environment ◽  
Uvb Radiation ◽  
Pisum Sativum L ◽  
Temperature Regimes ◽  
Varietal Variation ◽  
Growth Chambers ◽  
Effects Of Temperature ◽  
Two Temperature

Environmental stress factors can influence methane (CH4) emissions from plants. There are a few studies on the interactive effects of stress factors on plant aerobic CH4, but none on the comparative evaluation of CH4 emissions between and among plant varieties. We examined the effects of temperature, UVB radiation, and watering regime on CH4 emissions from 10 pea (Pisum sativum L.) varieties first and then selected two varieties with the highest (237J Sundance; var. 1) and lowest (422 Ho Lan Dow; var. 2) emissions for further studies. Plants were grown in controlled-environment growth chambers under two temperature regimes (22 °C / 18 °C and 28 °C / 24 °C, 16 h light / 8 h dark), two UVB levels (0 and 5 kJ·m−2·d−1), and two watering regimes (well-watered and water-stressed) for 14 days, after one week of growth under 22 °C / 18 °C. Higher temperatures and water stress increased CH4 emissions, and increased emission was associated with stress. Pea varieties varied in growth and CH4 emissions; var. 1 was more stressed and had higher emission than var. 2. In the stressed variety, the water-stressed plants grown under higher temperatures at UVB5 had the highest CH4 emission, whereas the well-watered plants grown under lower temperatures at UVB5 had the lowest emission. We conclude that climatic stress conditions increase CH4 emissions, which vary with plant varieties.

Drugs of abuse and benzodiazepines in the Madrid Region (Central Spain): Seasonal variation in river waters, occurrence in tap water and potential environmental and human risk

2014 ◽  
Vol 70 ◽  
pp. 76-87 ◽  
Author(s):  
A. Mendoza ◽  
J.L. Rodríguez-Gil ◽  
S. González-Alonso ◽  
N. Mastroianni ◽  
M. López de Alda ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Drugs Of Abuse ◽  
Tap Water ◽  
Central Spain ◽  
River Waters ◽  
Human Risk

Polyphenol Variation in Sitka Spruce

1975 ◽  
Vol 5 (1) ◽  
pp. 26-37 ◽  
Author(s):  
G. I. Forrest
Keyword(s):  
Seasonal Variation ◽  
High Temperature ◽  
Phenolic Content ◽  
Sitka Spruce ◽  
Main Stem ◽  
Temperature Regimes ◽  
Lower Temperature

The distribution of polyphenols in various tissues of Sitka spruce is described, with data on seasonal variation. Leaves were rich in a variety of flavonoids, but the main stem constituents were stilbenes. There was great variation both between and within provenances in most components, but evidence was obtained for differences in stilbene content attributable to provenance. Different temperature regimes caused marked differences in phenolic content, but clonal characteristics generally overrode treatment differences. High temperature favored polymeric polyphenol synthesis, while a lower temperature promoted high phenolic accumulations especially of monomeric components.

Seasonal Variation of Backcalculated Subgrade Moduli

1997 ◽  
Vol 1577 (1) ◽  
pp. 70-80 ◽  
Author(s):  
Bing Long ◽  
Mustaque Hossain ◽  
Andrew J. Gisi
Keyword(s):  
Seasonal Variation ◽  
Moisture Content ◽  
Temperature Effect ◽  
Resilient Modulus ◽  
Natural Soil ◽  
Temperature Regimes ◽  
Almost All ◽  
Moisture Conditions ◽  
Falling Weight ◽  
And Behavior

Seasonal variations in pavement material properties and behavior due to variations in temperature and moisture conditions are known to affect the structural performance of pavement. Temperature, subgrade moisture content, and falling weight deflectometer (FWD) deflection data were collected monthly on four asphalt pavement test sections for a year. Subgrade moduli were backcalculated using the elastic layer theory with two calculation schemes and pavement models. Backcalculation of subgrade moduli by subdividing the subgrade into a compacted subgrade layer and a natural soil subgrade layer resulted in compacted subgrade moduli that are more sensitive to the seasonal variation for all sites. It was found that for almost all sites, the patterns of subgrade response, in terms of subgrade moduli versus subgrade moisture content, simulated sine-shaped forms signifying a temperature effect. The temperature effect was confirmed by the strong correlation between backcalculated subgrade moduli and pavement surface temperature during FWD tests. The lowest backcalculated subgrade moduli were obtained for two sections during months when asphalt surface temperatures were excessively high (greater than 40°C). Both backcalculation schemes showed similar trends in variation of subgrade moduli over seasons. When the AASHTO relative damage concept was used to compute the effective roadbed soil resilient modulus for design, similar values were found for both schemes for most of the sites. The minimum frequency of FWD testing to capture the seasonal variation of subgrade was found to be three tests per year, or testing every fourth month, assuming that unusually high temperature regimes could be avoided.

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.

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