ABSCISIC ACID LEVELS AND GENETIC COMPACTION IN APPLE SEEDLINGS

1977 ◽  
Vol 57 (1) ◽  
pp. 81-85 ◽  
Author(s):  
J. M. LEE ◽  
N. E. LOONEY
Keyword(s):  
Abscisic Acid ◽  
Rapid Method ◽  
Growth Habit ◽  
Shoot Tip ◽  
Malus Sylvestris ◽  
Growth Types ◽  
Compact Growth ◽  
Controlled Crosses

Apple (Malus sylvestris Mill.) seedlings arising from controlled crosses involving McIntosh Wijcik segregate reliably into normal and compact growth types. The compact or spur-type seedlings have shorter, thicker stems; shorter internodes; and a strong upright, nonbranching growth habit. They contained less free ABA per shoot tip than normal seedlings. A reliable and rapid method for extracting and measuring ABA is described.

scholarly journals SEGREGATION OF COMPACT GROWTH TYPES IN CERTAIN APPLE SEEDLING PROGENIES

1969 ◽  
Vol 49 (6) ◽  
pp. 765-768 ◽  
Author(s):  
K. O. Lapins
Keyword(s):  
Growth Habit ◽  
Characteristic Number ◽  
Apple Seedling ◽  
Growth Type ◽  
Internodal Length ◽  
Growth Types ◽  
Compact Growth ◽  
Radiation Induced ◽  
One Year ◽  
Careful Assessment

Two-year-old apple seedlings of six progenies resulting from crosses between cultivars of standard growth or their compact mutants were classified for standard or compact growth type. A natural compact mutant of McIntosh (Wijcik) in combination with Golden Delicious transmitted compact growth habit to 43.9% of its progeny, whereas the radiation-induced compact mutant of McIntosh (8F-2-27), in the same combination did not transmit this characteristic. Number of side shoots, internodal length, and the ratio of length to diameter of one-year-old shoots were useful characteristics in distinguishing between the standard and compact growth types in two-year-old seedling trees. As the segregation of seedlings of compact growth habit is of great interest both from theoretical and practical aspects, a careful assessment of the transmissibility of compactness by mutant and non-mutated cultivars in various cross-combinations is suggested.

The responses to defoliation of two strains of subterranean clover, differing in growth habit, when grown in swards

1980 ◽  
Vol 31 (1) ◽  
pp. 77 ◽  
Author(s):  
RC Rossiter ◽  
WJ Collins
Keyword(s):  
Growth Habit ◽  
Total Yield ◽  
Initial Density ◽  
Subterranean Clover ◽  
Daily Maximum ◽  
Low Density ◽  
Compact Growth ◽  
Effective Yield ◽  
Principal Finding ◽  
Cutting Height

Dense swards of two strains of T. subterraneum-herein referred to as C and P-were compared at two heights of cutting-1.5 cm (low) and 5.0 cm (high)-and two frequencies of defoliation- 1-weekly (frequent) and 4- or 5-weekly (infrequent). Strain C has smaller leaves than P and a compact, in contrast to a lax, growth habit. The swards (initial density of c. 25 plants/dm2) were grown in boxes, out of doors, at Perth from 27 April to 20 September. Mean daily solar radiation varied from c. 10 to 16 MJ/m2 and average daily maximum and minimum temperatures were c. 20� and 10�C respectively. The principal finding was that under defoliation stress (i.e. low cutting) strain C yielded more than P, whereas at a lower level of stress (high cutting) there was usually little if any difference between these strains. This effect was established for the most part before the first harvest, at day 55; thereafter, with continued defoliation stress, strain P appeared to worsen slightly relative to C. The results provide support for the view that strains with a compact growth habit are less susceptible to defoliation (or grazing) stress than taller strains of lax growth habit. Generally, the total yield of tops and also the effective yield (as cut and removed material) decreased when cutting height was lowered. Also, infrequent cutting increased effective yield, particularly under low density (four plants/dm2) as observed in an ancillary experiment.

scholarly journals LONG DAYS PROMOTE FLOWERING OF ARMERIA MARITIMA

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 575e-575
Author(s):  
J.T. Lehmann ◽  
M.L. Albrecht
Keyword(s):  
Cold Storage ◽  
Growth Habit ◽  
Leaf Length ◽  
Plant Production ◽  
Night Temperature ◽  
Potted Plant ◽  
Compact Growth ◽  
Armeria Maritima ◽  
Vegetatively Propagated Plants ◽  
Short Days

Armeria maritima was studied to provide guidelines for flowering potted plant production. Seed and vegetatively propagated plants were exposed to 9-hr, 13-hr, or 17-hr photoperiods. Flowering was enhanced under the 13-hr and 17-hr photoperiods. Peduncle and leaf length were shorter, and plants were more compact under short days (SD, 9-hr photoperiod) than under long days (LD). When grown under SDs then moved at monthly intervals to LDs, the degree to which the compact growth habit (CH) was expressed was dependent upon the length of exposure to SDs. Plants with the CH produced fewer inflorescences than full growth habit plants. Plants held in cold storage (4C) flowered more profusely under LDs, but had a delay in flowering. There was more uniform flowering for plants held in cold storage than those held in a cool greenhouse (7C night temperature).

scholarly journals Preculture Conditions Influence Cold Hardiness and Regrowth of Pyrus cordata Shoot Tips After Cryopreservation

HortScience ◽  
2001 ◽  
Vol 36 (7) ◽  
pp. 1329-1333 ◽  
Author(s):  
Yongjian Chang ◽  
Barbara M. Reed
Keyword(s):  
Abscisic Acid ◽  
Cold Hardiness ◽  
Tip Growth ◽  
Synergistic Effects ◽  
Sucrose Concentration ◽  
Shoot Tips ◽  
Shoot Tip ◽  
Lateral Buds ◽  
Successful Recovery ◽  
Sucrose Medium

Cold hardiness and cryogenic survival of micropropagated pear (Pyrus cordata Desv.) shoots were evaluated after pretreatments with ABA and sucrose. Shoot cold hardiness increased by 3 °C, and cryopreserved shoot tip growth increased by 17% after a 4-week 150 μm ABA pretreatment. Low temperature (LT) pretreatments improved the recovery of cryopreserved P. cordata shoot tips. Six to 10 weeks of LT were required for reaching high cryopreservation recovery. ABA and LT treatments produced significant synergistic effects on both cold hardiness and cryopreservation recovery. ABA shortened the LT requirement for high cryopreservation growth from 10 to 2 weeks. The optimal treatment for recovery of cryopreserved shoot tips was a 3 week culture on 50 μm ABA followed by 2 weeks of LT, while the maximum cold hardiness (-22.5 °C) was obtained with 150 μm ABA and 2-week LT. A 4 week culture on 150 μm ABA at 25 °C induced dormancy in 74% of shoot tips, but had little effect on cryopreservation growth unless combined with LT. Control and ABA-treated shoot tips, lateral buds, and leaves had similar cold hardiness (-10 to -12 °C), but LT and LT+ABA-treated shoot tips survived the lowest temperatures (-17 to -23 °C), lateral buds next (-15 to -20 °C), and finally leaves (-14 to -18 °C). An increase in the preculture-medium sucrose concentration from 2% to 7% combined with 2-week LT significantly increased cryopreserved shoot tip growth (0% to 75%) and decreased the LT50 from -7.8 to -12.4 °C. The optimal shoot pretreatment for successful recovery of cryopreserved P. cordata shoot tips was a 3 week culture on either 50 μm ABA or 5% to 7% sucrose medium followed by 2 weeks of LT, and increased shoot tip growth from zero to >70%. Chemical name used: abscisic acid (ABA).

scholarly journals Spray and Drench Treatments of Paclobutrazol Influence Growth of Dissotis and Tibouchina

HortScience ◽  
2015 ◽  
Vol 50 (10) ◽  
pp. 1514-1517
Author(s):  
Susan M. Hawkins ◽  
John M. Ruter ◽  
Carol D. Robacker
Keyword(s):  
Adverse Effects ◽  
Plant Growth ◽  
Plant Growth Regulator ◽  
Growth Habit ◽  
Dry Weight ◽  
Spray Application ◽  
Compact Growth ◽  
Nursery Production ◽  
Growth Habits ◽  
Open Growth

Dissotis rotundifolia (Sm.) Triana and Tibouchina fothergillae ×pilosa are members of the Melastomataceae family with high ornamental potential. The growth habits of these species are not ideal for nursery production or shipping. D. rotundifolia grows rapidly and needs frequent pruning. T. fothergillae ×pilosa has an open growth habit and could benefit from a more compact form. The effect of the plant growth regulator (PGR) paclobutrazol on D. rotundifolia and T. fothergillae ×pilosa was assessed to determine whether it could produce plants with a more compact growth habit. Paclobutrazol was applied as a drench and a spray. Drench application was more effective in reducing the growth of both species. Spray application was effective in reducing the growth of D. rotundifolia but was not effective on T. fothergillae ×pilosa. Neither drench nor spray application delayed or reduced flowering in D. rotundifolia. T. fothergillae ×pilosa did not flower during the study. For both D. rotundifolia and T. fothergillae ×pilosa, neither drench nor spray application had an effect on root dry weight. Low-to-medium dosages were effective at controlling plant growth in D. rotundifolia and T. fothergillae ×pilosa without adverse effects on plants. Drench treatments have more persistent effects on plant growth than spray treatments.

Bud Sprouting and Growth of Purple Nutsedge Altered by Benzyladenine

Weed Science ◽  
1973 ◽  
Vol 21 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Chris K. H. Teo ◽  
Leo E. Bendixen ◽  
Roy K. Nishimoto
Keyword(s):  
Abscisic Acid ◽  
Gibberellic Acid ◽  
Indoleacetic Acid ◽  
Growth Habit ◽  
Cyperus Rotundus ◽  
Purple Nutsedge ◽  
Bud Sprouting ◽  
Continuous Presence ◽  
Delayed Flowering

Varying concentrations of benzyladenine (BA), indoleacetic acid (IAA), gibberellic acid (GA), abscisic acid (ABA), and 2-chloroethylphosphonic acid (ethephon) were used to induce sprouting of dormant purple nutsedge (Cyperus rotundusL.) tubers. BA at 50 to 300 ppm stimulated sprouting. The continuous presence of BA during the sprouting period was necessary to give significant sprout stimulation. Neither IAA at 1, 10, or 100 ppm; GA at 10, 100, or 1000 ppm; nor ethephon at 10, 100, or 1000 ppm had stimulatory effects on sprouting. ABA counteracted the stimulatory effects of BA when tubers were treated with ABA following BA treatment. Sprouting was markedly greater at 33 C day, 25 C night than at 24 C day, 17 C night. Growth of plants originating from tubers pretreated with 100 ppm BA did not differ significantly from the controls. Sustained BA applications at 100 and 200 ppm produced numerous plants with tuft-type growth habit, delayed flowering, and reduced the number of inflorescences. Numerous short, diageotropic rhizomes were produced.

scholarly journals A Rapid Method for the Extraction and Analysis of Abscisic Acid from Plant Tissue

1980 ◽  
Vol 65 (3) ◽  
pp. 523-525 ◽  
Author(s):  
Kerry T. Hubick ◽  
David M. Reid
Keyword(s):  
Abscisic Acid ◽  
Rapid Method ◽  
Plant Tissue
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