Gibberellin-like activity in shoots of Salix pentandra as related to the elongation growth

1982 ◽  
Vol 60 (7) ◽  
pp. 1231-1234 ◽  
Author(s):  
Olavi Junttila
Keyword(s):  
Marked Reduction ◽  
Shoot Elongation ◽  
Apical Part ◽  
Apical Growth ◽  
Shoot Tip ◽  
Flower Buds ◽  
Natural Conditions ◽  
Growth Cessation ◽  
Salix Pentandra ◽  
Lateral Flower

Activities of acidic gibberellin(GA)-like substances in shoots of Salix pentandra trees growing under natural conditions (69°39′ N, 18°37′ E) were studied in relation to shoot elongation and tip abscission. Bioassay after separation on SiO2 partition columns was accomplished with the lettuce hypocotyl and dwarf rice 'Tan-ginbozu' assays. The GA-like activity in the apical part of the shoot greatly decreased before cessation of growth and shoot tip abscission. In the basal part of the shoot the marked reduction of GA-like substances occurred well before shoot tip abscission and even before shoot elongation had ceased. Low GA-like activity in the shoot may be a prerequisite for apical growth cessation and for the development of lateral flower buds.

Apical Growth Cessation and Shoot Tip Abscission in Salix

1976 ◽  
Vol 38 (4) ◽  
pp. 278-286 ◽  
Author(s):  
OLAVI JUNTTILA
Keyword(s):  
Apical Growth ◽  
Shoot Tip ◽  
Growth Cessation

scholarly journals Fat-soluble Components of Lateral Flower Buds from Different Varieties of Broccoli (Brassica oleracea L. var. italica Plen).

1992 ◽  
Vol 45 (5) ◽  
pp. 453-455 ◽  
Author(s):  
Toshiro HIDAKA ◽  
Nobuhiro FUKUDA ◽  
Keiko TANIGUCHI ◽  
Junichi KANZAKI
Keyword(s):  
Brassica Oleracea ◽  
Flower Buds ◽  
Lateral Flower ◽  
Brassica Oleracea L ◽  
Soluble Components

scholarly journals In Vitro Micropropagation of Orchid (Vanda tessellata L.) from Shoot Tip Explant

1970 ◽  
Vol 17 ◽  
pp. 139-144 ◽  
Author(s):  
MS Rahman ◽  
MF Hasan ◽  
R Das ◽  
MS Hossain ◽  
M Rahman
Keyword(s):  
Multiple Shoots ◽  
Shoot Elongation ◽  
Shoot Formation ◽  
Multiple Shoot ◽  
Shoot Tips ◽  
Shoot Tip ◽  
Root Induction ◽  
Ms Medium ◽  
Culture Techniques

Context: Orchid produces a huge number of minute seeds but the seeds can not germinate easily in nature due to the lack of endosperm in the seeds is an incompatibility barrier that limits its propagation in nature. Objectives: To develop in vitro culture techniques for quick propagation of Vanda tessellate, a commercially important orchid species. Materials and Methods: Shoot tips were used as experimental materials. The explants were surface sterilized and the shoot tips were excised. The isolated shoot tips were cultured in MS medium supplemented with different concentration and combinations of auxin and cytokinin. Results: The combination of 1.5 mgl-1 NAA and 1.0 mgl-1 BAP was proved to be the best medium formulation for multiple shoot formation as well as maximum shoot elongation. The single shoots were isolated from the multiple shoots and subcultured in MS medium having NAA and IBA individually and in combinations for root induction. Maximum root induction was obtained in MS agarified medium having 0.5 mgl-1NAA and 1.0 mgl-1IBA. The well rooted plantlets were hardened successfully in the potting mixture containing coconut husk, perlite, charcoal, brick pieces in the ratio of 2:1:1:1 and eventually established under natural condition.Conclusion: An efficient regeneration protocol for micropropagation in V. tessellata through shoot tip culture has been established.Key words: Shoot tip; micropropagation; orchid.DOI: 10.3329/jbs.v17i0.7122J. bio-sci. 17: 139-144, 2009

Stimulation of shoot elongation in Salix pentandra by gibberellin A9; activity appears to be dependent upon hydroxylation to GAl via GA20

1992 ◽  
Vol 84 (1) ◽  
pp. 113-120 ◽  
Author(s):  
Olavi Junttila ◽  
Einar Jensen ◽  
David W. Pearce ◽  
Richard P. Pharis
Keyword(s):  
Shoot Elongation ◽  
Salix Pentandra ◽  
Stimulation Of

Photoperiodic Regulationof Apical Growth Cessation in Northern Tree Species

2004 ◽  
Vol 10 (1-2) ◽  
pp. 77-112 ◽  
Author(s):  
Jorunn E. Olsen ◽  
John B. Jensen ◽  
Jorgen A. Molmann ◽  
Arild Ernstsen ◽  
Olavi Junttila
Keyword(s):  
Tree Species ◽  
Apical Growth ◽  
Growth Cessation

Interaction between gibberellin A4/7 and root-pruning on the reproductive and vegetative processes in Douglas-fir. III. Effects on anatomy of shoot elongation and terminal bud development

1985 ◽  
Vol 15 (2) ◽  
pp. 354-364 ◽  
Author(s):  
J. N. Owens ◽  
J. E. Webber ◽  
S. D. Ross ◽  
R. P. Pharis
Keyword(s):  
Shoot Elongation ◽  
Douglas Fir ◽  
Apical Growth ◽  
Root Pruning ◽  
Bud Development ◽  
Leaf Initiation ◽  
Terminal Bud ◽  
Terminal Buds ◽  
Effective Cone ◽  
Vegetative Bud

The relative importance of cell division and cell elongation to shoot elongation and the anatomical changes in vegetative terminal apices were assessed for 9- and 10-year-old seedlings of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) in response to two effective cone-induction treatments, gibberellin A4/7 (GA4/7) and root-pruning (RP). Root-pruning was done in mid-April at the start of vegetative bud swelling and GA treatments were begun at vegetative bud flushing in mid-May and continued until early July. Shoot elongation before flushing resulted primarily from cell divisions and was not affected by the RP treatment. Shoot elongation after flushing resulted primarily from cell expansion which was reduced by RP treatments. Root-pruning significantly slowed mitotic activity, apical growth, and development of vegetative terminal buds from mid-June through mid-July. Apical growth then resumed during leaf initiation and the final number of leaf primordia initiated was not affected. This resulted in a delay of 2 to 4 weeks in the transition from bud-scale to leaf initiation. Retarded terminal vegetative apices anatomically resembled latent axillary apices but were never completely inhibited. GA + RP had the same effect as RP. GA4/7 alone had no effect on shoot or apical development. These results show that RP and GA + RP significantly retard shoot elongation and terminal bud development but still allow normal development of vegetative terminal buds. Retardation of bud development by a few weeks shifts the critical morphogenetic phase of transition from bud scale to leaf initiation to a later time when endogenous and environmental conditions may differ from the normal.

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 In vitro Propagation and Plantlet Regeneration from Doritaenopsis Purple Gem ‘Ching Hua’ Flower Explants

HortScience ◽  
2007 ◽  
Vol 42 (5) ◽  
pp. 1256-1258 ◽  
Author(s):  
Wagner A. Vendrame ◽  
Ian Maguire ◽  
Virginia S. Carvalho
Keyword(s):  
Clonal Propagation ◽  
Shoot Multiplication ◽  
Naphthalene Acetic Acid ◽  
Shoot Induction ◽  
Flower Buds ◽  
Flower Stem ◽  
Normal Flower ◽  
Regenerated Plantlets ◽  
Lateral Flower

The effects of four types of explants removed from 10-cm flower stalks of Doritaenopsis Purple Gem ‘Ching Hua’ (immature apical flower buds, immature lateral flower buds, flower stem nodes, and flower pedicel sections) and combinations of two plant growth regulators [naphthalene acetic acid (NAA) and thidiazuron (TDZ)] on direct in-vitro shoot induction and multiplication were studied. Immature apical flower buds were the only explants that showed induction and multiplication of shoots in vitro. NAA at 5.4 and 10.7 μm combined with either 4.5 or 9.1 μm TDZ provided the fastest and greatest percentages of shoot induction (27% to 40%) and the greatest numbers of shoot multiplication (111–160 shoots per explant). In vitro–induced shoots were rooted on medium containing 5.4 μm NAA and developed into plantlets with normal vegetative and reproductive morphology. Regenerated plantlets were acclimatized, showing 100% survival and establishment in greenhouse. Plantlets were grown to maturity and showed normal flower morphology. No floral off-types were observed. The high rates of shoot multiplication obtained offer a means for mass clonal propagation of this and possibly other related Doritaenopsis hybrids.

scholarly journals A Comparison of the Effects of Cycocel and Tipping on Fruit Set in Vitis Vinifera L

1969 ◽  
Vol 22 (6) ◽  
pp. 1305 ◽  
Author(s):  
KGM Skene
Keyword(s):  
Vitis Vinifera ◽  
Fruit Set ◽  
Shoot Elongation ◽  
Shoot Tip ◽  
Vitis Vinifera L ◽  
Cabernet Sauvignon ◽  
Rooted Cuttings ◽  
Nutrient Culture ◽  
Treat Ment ◽  
Nutrient Solutions

Rooted cuttings of V. vinifet'a cv. Cabernet Sauvignon were grown in nutrient culture solutions. When Cycocel [(2-chloroethyl)trimethylammonium chlorideJ was added to the nutrient solutions, plants retained 40% of their berries. Plants from which the shoot tip was removed at anthesis, either with or without Cycocel treat-ment, showed similar fruit set. Control plants retained only 20% of their berries. Percentage fruit set was inversely related to the rate of shoot elongation during the week following anthcsis. The results suggest that treatment with Cycocel and tipping increase fruit set by reducing competition between the developing leaves and ovaries for available metabolites.

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