scholarly journals A Model Describing rRelease of Flower Bud Dormancy in `Prize' and `Gloria' Azaleas

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 760B-760
Author(s):  
William M. Womack ◽  
James E. Barrett ◽  
Terril A. Nell
Keyword(s):  
Growth Regulators ◽  
Bud Dormancy ◽  
Flower Bud ◽  
Cooling Temperature ◽  
Growth Chambers ◽  
Cool Treatment

`Prize' and `Gloria' azaleas were budded at 29C day/24C night without growth regulators. Dormant-budded plants were held at 2, 7, 13, or 18C for 0, 0.5, 1, 2, 4, 6, 8, or 10 weeks and then forced in walk-in growth chambers (29C day/24C night). A model was developed to describe the effect of cooling temperature and duration on days to marketability (eight open flowers) and percent of buds showing color. Holding at temperatures below 7C, increases days to marketability up to 7 days. Extended cooling (beyond 6 weeks) at temperatures <7C increases percent of buds showing color. Extended holding at temperatures >7C decreases buds in color due to development of bypass shoots during cooling and increased bud abortion. Plants not receiving a cool-treatment or cooled for <2 weeks do not flower uniformly. Furthermore, the percentage of plants reaching marketability dramatically decreases for plants held longer than 6 weeks at temperatures >7C. Both cultivars show similar trends, but `Gloria' has greater variability.

Cyclamen Leaf Unfolding Rate in Response to Temperature

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 447d-447
Author(s):  
Meriam Karlsson ◽  
Jeffrey Werner
Keyword(s):  
Day Length ◽  
Leaf Number ◽  
Cyclamen Persicum ◽  
Flower Buds ◽  
Flower Bud ◽  
Leaf Unfolding ◽  
Significant Difference ◽  
Number Of Leaves ◽  
Growth Chambers ◽  
Response To Temperature

Nine-week-old plants of Cyclamen persicum `Miracle Salmon' were transplanted into 10-cm pots and placed in growth chambers at 8, 12, 16, 20, or 24 °C. The irradiance was 10 mol/day per m2 during a 16-h day length. After 8 weeks, the temperature was changed to 16 °C for all plants. Expanded leaves (1 cm or larger) were counted at weekly intervals for each plant. The rate of leaf unfolding increased with temperature to 20 °C. The fastest rate at 20 °C was 0.34 ± 0.05 leaf/day. Flower buds were visible 55 ± 7 days from start of temperature treatments (118 days from seeding) for the plants grown at 12, 16, or 20 °C. Flower buds appeared 60 ± 6.9 days from initiation of treatments for plants grown at 24 °C and 93 ± 8.9 days for cyclamens grown at 8 °C. Although there was no significant difference in rate of flower bud appearance for cyclamens grown at 12, 16, or 20 °C, the number of leaves, flowers, and flower buds varied significantly among all temperature treatments. Leaf number at flowering increased from 38 ± 4.7 for plants at 12 °C to 77 ± 8.3 at 24 °C. Flowers and flower buds increased from 18 ± 2.9 to 52 ± 11.0 as temperature increased from 12 to 24 °C. Plants grown at 8 °C had on average 6 ± 2 visible flower buds, but no open flowers at termination of the study (128 days from start of treatments).

scholarly journals Chemical regulation of sex expression in certain olive cultivars

2013 ◽  
Vol 35 (2) ◽  
pp. 185-190 ◽  
Author(s):  
E. S. Hegazi ◽  
G. R. Stino
Keyword(s):  
Growth Regulators ◽  
Sex Expression ◽  
Bud Burst ◽  
Flower Bud ◽  
Bud Formation ◽  
Noticeable Increase ◽  
Time Of Application ◽  
Olive Cultivars ◽  
Modifying Effect ◽  
Flower Bud Formation

The modifying effect of growth regulators on bud burst, flower bud formation and sex expression in olives varies greatly according to cultivar, concentration and time of application. Cycocel 200, 500 mg/l, ethephon 200 mg/l and SADH 2000 mg/l stimulated bud burst and flower bud formation in the 'Blanquetta' cv. A noticeable increase in the percentage of perfect flowers was obtained by 100 mg/l of kinetin, and 200 mg/l of Cycocel in the cv. 'Picual', Ethephon 200/1, Cycocel 200 mg/l and SADH 2000 mg/l considerably increased the percentage of perfect flowers in the cvs 'Blanquetta', 'Serrana' and 'Picual'. Treatments at green cluster stage were not effective.

The Effects of Some Growth Regulators on Peach Flower Bud Abscission

1974 ◽  
Vol 49 (4) ◽  
pp. 373-381
Author(s):  
W. K. Thompson ◽  
D. L. Jones ◽  
D. G. Nichols
Keyword(s):  
Growth Regulators ◽  
Flower Bud

Variations in kinetin-like activity in buds of Betula and Populus during release from dormancy

1968 ◽  
Vol 46 (4) ◽  
pp. 397-403 ◽  
Author(s):  
Romuald Domanski ◽  
Theodore T. Kozlowski
Keyword(s):  
Growth Regulators ◽  
Bud Dormancy ◽  
Warm Water ◽  
Betula Papyrifera ◽  
Populus Balsamifera ◽  
Growth Promoters ◽  
Water Extracts ◽  
Endogenous Cytokinins ◽  
Chlorophyll Retention ◽  
Test Plants

Levels of kinetin-like activity in dormant buds and buds at various stages of release from dormancy were determined by an assay involving retardation by kinetin-like substances of chlorophyll degradation in tissue of senescing leaves of Raphanus test plants. Dormancy of buds of Betula papyrifera and Populus balsamifera cuttings was broken by exposure to 2-chloroethanol vapor or immersion in warm water. Water extracts of buds at various stages of dormancy were separated by ascending chromatography and active Rf values identified. The amount of kinetin-like activity at various stages of bud dormancy was then determined by observing effects of active Rf values of bud extracts on senescence (chlorophyll retention) of Raphanus plants. Kinetin-like activity was absent in dormant buds of both species and was present in various amounts after dormancy was broken. In Betula, such activity was found primarily at Rf values of 0.3 to 0.5, and secondarily at 1.0. In Populus, kinetin-like activity was found at Rf values 0.5 to 0.6 and 0.9 to 1.0. Kinetin-like activity was greater in non-dormant buds of Populus than in those of Betula. However, the trend of variation in activity with time after breaking of dormancy was similar in both species. After bud dormancy was broken, kinetin-like activity in both species increased progressively until shortly before buds opened, and it decreased thereafter. Evidence is cited that release of buds from dormancy involves a change in the balance of growth regulators, with various growth promoters increasing to overcome the effects of inhibitors. Endogenous cytokinins appear to be involved, together with other growth promoters, in regulating release of buds from dormancy.

scholarly journals Analysis of Evolution, Expression and Genetic Transformation of TCP Transcription Factors in Blueberry Reveal That VcTCP18 Negatively Regulates the Release of Flower Bud Dormancy

2021 ◽  
Vol 12 ◽  
Author(s):  
Yongqiang Li ◽  
Shuang An ◽  
Qiangqiang Cheng ◽  
Yu Zong ◽  
Wenrong Chen ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Plant Growth ◽  
Gene Family ◽  
Fruit Development ◽  
Germination Rate ◽  
Expression Patterns ◽  
Bud Dormancy ◽  
Dormancy Release ◽  
Flower Bud ◽  
Bud Dormancy Release

Plant-specific TEOSINTE BRANCHED 1, CYCLOIDEA, PROLIFERATING CELL FACTORS (TCP) transcription factors have versatile functions in plant growth, development and response to environmental stress. Despite blueberry’s value as an important fruit crop, the TCP gene family has not been systematically studied in this plant. The current study identified blueberry TCP genes (VcTCPs) using genomic data from the tetraploid blueberry variety ‘Draper’; a total of 62 genes were obtained. Using multiple sequence alignment, conserved motif, and gene structure analyses, family members were divided into two subfamilies, of which class II was further divided into two subclasses, CIN and TB1. Synteny analysis showed that genome-wide or segment-based replication played an important role in the expansion of the blueberry TCP gene family. The expression patterns of VcTCP genes during fruit development, flower bud dormancy release, hormone treatment, and tissue-specific expression were analyzed using RNA-seq and qRT-PCR. The results showed that the TB1 subclass members exhibited a certain level of expression in the shoot, leaf, and bud; these genes were not expressed during fruit development, but transcript levels decreased uniformly during the release of flower bud dormancy by low-temperature accumulation. The further transgenic experiments showed the overexpression of VcTCP18 in Arabidopsis significantly decreased the seed germination rate in contrast to the wild type. The bud dormancy phenomena as late-flowering, fewer rosettes and main branches were also observed in transgenic plants. Overall, this study provides the first insight into the evolution, expression, and function of VcTCP genes, including the discovery that VcTCP18 negatively regulated bud dormancy release in blueberry. The results will deepen our understanding of the function of TCPs in plant growth and development.

scholarly journals AN IN VITRO BIOASSAY FOR THE EVALUATION OF COLD TREATMENT ON FLOWER BUD DORMANCY IN CAMELLIA

2012 ◽  
pp. 607-611
Author(s):  
A. Berruti ◽  
A. Christiaens ◽  
M.C. Van Labeke ◽  
V. Scariot
Keyword(s):  
Cold Treatment ◽  
Bud Dormancy ◽  
In Vitro Bioassay ◽  
Flower Bud
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