scholarly journals Diffusible and Extractable Growth Regulators in Normal and Dwarf Shoot Apices of Peach, Prunus persica Batsch

1971 ◽  
Vol 48 (1) ◽  
pp. 91-93 ◽  
Author(s):  
Anthony Wylie ◽  
Kay Ryugo
1984 ◽  
Vol 11 (2) ◽  
pp. 49 ◽  
Author(s):  
IR Dann ◽  
RA Wildes ◽  
DJ Chalmers

The distribution of current assimilates between competing zones of potential growth in the peach tree (Prunus persica (L.) Batsch) was studied using limb girdling, which altered the balance between reproductive growth and vegetative growth in a similar manner to the aging process. Fruit matured earlier, and leaf senescence and abscission were advanced in girdled limbs. which supported normal fruit loads but had only half the leaf area. Lateral growth and secondary thickening were reduced by 50% but vegetative growth approached normal rates at times when fruit growth was minimal, indicating that girdling reduced the ability of vegetative growth to compete with reproductive growth for assimilates. Starch and soluble sugars did not accumulate above the girdles. The data are consistent with the hypothesis that girdling alters the balance between endogenous growth regulators which favour either vegetative or reproductive development. We suggest that the initial effects on the girdled limb are attributable to accumulation of growth regulators produced above the girdle. The reduced flow of growth regulators to the roots eventually results in lowered levels of root-produced hormones which subsequently causes effects throughout the tree.


1975 ◽  
Vol 39 (12) ◽  
pp. 2399-2403 ◽  
Author(s):  
Isomaro YAMAGUCHI ◽  
Takao YOKOTA ◽  
Noboru MUROFUSHI ◽  
Nobutaka TAKAHASHI ◽  
Yukiyoshi OGAWA

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 698c-698
Author(s):  
Veronique Declerck ◽  
Schuyler S. Korban

Leaf segments of Prunus persica L. (peach) collected from greenhouse-grown plants and from micropropagated shoots were cultured on a basal medium containing half-strength Murashige and Skoog (MS), Staba vitamins, sucrose (30 g/1) and agar (6.5 g/l); medium adjusted to pH 5.6. The influence of 6 different growth regulators at 3 concentrations (5, 10, 15 μM) were investigated using leaf explants from proliferating shoots of 'Elberta Queen' peach. With thidiazuron (TDZ), compact and multiple green calli were obtained; with benzyladenine and zeatin, lower numbers of small sized calli were obtained; with kinetin, no callus development was observed. Among auxin treatments, both Dicamba and 2,4-D resulted in friable white and yellow calli. Most of the calli produced in all treatments were formed along the cut margins of the explants. In an another experiment, leaf explants of' Bellaire' (greenhouse) and `Elberta Queen' (in vitro shoots) were used to determine the influence of a large scale concentration of TDZ (3 to 23 |iM). Explants from greenhouse and in vitro leaves resulted in higher levels of callus development at TDZ concentrations of 8-13 μM. Higher TDZ levels resulted in necrosis of leaf explants. The-influence of different carbon sources on callogenesis was investigated. We observed more green and compact calli with glucose than with sucrose and fructose at 100 mM. The influence of the glucose at 10 different concentrations (30 to 300 mM) was also investigated.


1977 ◽  
Vol 4 (3) ◽  
pp. 359 ◽  
Author(s):  
RP Zigas ◽  
BG Coombe

Treatment of peach embryos from partially stratified seeds with abscisic acid (ABA) inhibited germination and promoted the production of leaf lesions, responses which are typical of testa presence. A period of water stress during germination also promoted lesion production. Neither testas nor ABA stimulated lesions on seedlings from 25°C-stratified seed, but mixtures of ABA and GA*3 were synergistic in promoting lesions; at the same time ABA and GA3 had opposite effects on germination and stem elongation, and mixtures had intermediate effects. Evidence was obtained for effects attributable to a balance between GA and ABA. Other inhibitors and promotors had no effect on lesions. The results from excision and substitution experiments permit an explanation of the effects of stratification in terms of three events: (a) a decrease in inhibitor activity in the testa; (b) an increase in gibberellin activity in the epicotyl; and (c) diffusion of inhibitor to the epicotyl via the radicle when the seed is returned to warm conditions.


1992 ◽  
Vol 117 (2) ◽  
pp. 346-350 ◽  
Author(s):  
Isabel Arrillaga ◽  
Victoria Lerma ◽  
Juan Segura

A protocol for in vitro propagation in flowering ash (Fraxinus ornus L.) has been developed. Shoot apices or nodal segments from aseptically grown seedings or shoot apices from adult trees were used as initial explants. Highest shoot multiplication rates were obtained when the explants were cultured for 30 days in liquid Rugini induction medium supplemented with BA followed by 30 days on solidified Rugini multiplication medium without growth regulators. Regenerated shoots were rooted on Heller medium containing auxins alone or in combination with BA. Rooting percentages up to 71% (juvenile material) or 50% (adult material) were obtained in the presence of NAA and BA, and were not improved by treating the basal end of the shoots with concentrated NAA solutions. Following conventional procedures, regenerated plants were transferred to soil with more than 80% success. Chemical names used: N-(phenylmethyl)-1H-purin-6-amine (BA); 1-naphthaleneacetic acid (NAA).


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 456b-456
Author(s):  
Dean R. Evert

Armothin® thinned `Sentinel' fruit on peach trees (Prunus persica L.) in 1993. Thinning increased as Armothin® rate in the single spray increased from 1.5X, to 3.0% to 6.0% (v:v) and as the percentage of open blossoms increased from 30% to 61%. The 1.5 % rate of Armothin® thinned significantly only on the third date, and the 6.0% rate overthinned slightly on the third date. Minor discoloration developed on the expanding leaves of a few of trees but disappeared in a few days. No leaf abscission occurred on treated trees and tree growth was normal. Variability between trees treated alike probably reflects the variability in bloom when sprayed. According to Akzo, Armothin® prevents pollination by reacting with the surface of the receptive stigma. Spraying after full bloom should selectively prevent fertilization of the last blossoms to open without destroying the fertilized fruit. This possibility will be tested in 1994. Armothin®, which is a contact thinner, seems to avoid the problems associated with thinners that act as growth regulators and with nonselective caustic thinners. Because of its low phytotoxicity and wide range of effective rates, Armothin® has great potential as a chemical thinner.


HortScience ◽  
1997 ◽  
Vol 32 (7) ◽  
pp. 1276-1277 ◽  
Author(s):  
Joao L.C. Faria ◽  
Juan Segura

A protocol for in vitro propagation in yellow passionfruit (Passiflora edulis F. flavicarpa Deg) has been developed. Shoot apices from aseptically grown seedlings were used as initial explants. Multiple shoot formation was obtained by placing the explants on solidified Murashige and Skoog medium containing BA. Regenerated shoots were rooted on media without growth regulators. Following conventional procedures, plantlets were transferred to soil with more than 90% success. Chemical name used: N-(phenylmethyl)-lH-purin-6-amine (BA).


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