Promotion of flowering in potted white spruce grafts by root pruning: its relationship to drought and shoot elongation

1991 ◽  
Vol 21 (5) ◽  
pp. 680-685 ◽  
Author(s):  
Stephen D. Ross
Keyword(s):  
Early Stage ◽  
White Spruce ◽  
Shoot Elongation ◽  
Threshold Level ◽  
Response To Treatment ◽  
Root Pruning ◽  
Flowering Response ◽  
Stress Effects ◽  
Female Flowering ◽  
Vegetative Bud

Flowering and shoot-elongation responses by potted white spruce (Piceaglauca (Moench) Voss) grafts to root pruning (RP) and drought, and to RP applied at different stages of root and shoot development, were investigated in separate experiments. Results suggest that RP does not simulate drought. Differences in midday needle water potentials between RP and non RP grafts were relatively small (0.1–0.2 MPa) and short lived following treatment. Furthermore, whereas RP only affected (promoted) female flowering, drought only affected (inhibited) male flowering. Shoot elongation was less inhibited by RP at initiation of new root growth in spring, compared with RP at the late vegetative bud swell stage and at the early stage of rapid shoot elongation, when root activity is naturally declining. However, the flowering response was independent of time of RP. The early RP treatment enhanced shoot elongation in some clones and inhibited it in others, and the effect was not related to the clone's flowering response to treatment. These results are discussed in relation to the hypothesis that in small, potted trees, at least, actively growing roots are an important source of certain gibberellins that are essential for both shoot elongation and cone-bud differentiation. Accordingly, RP may inhibit or enhance shoot elongation, depending on whether the supply of gibberellins from roots newly regenerated following RP exceeds that from existing roots removed in treatment. Flowering occurs when the supply of gibberellins exceeds some threshold level either because of reduced vegetative demand (due to water-stress effects) or increased synthesis by roots.

Interaction between gibberellin A4/7 and root-pruning on the reproductive and vegetative process in Douglas-fir. II. Effects on shoot elongation and its relationship to flowering

1985 ◽  
Vol 15 (2) ◽  
pp. 348-353 ◽  
Author(s):  
J. E. Webber ◽  
S. D. Ross ◽  
R. P. Pharis ◽  
J. N. Owens
Keyword(s):  
Synergistic Effect ◽  
Vegetative Growth ◽  
Shoot Growth ◽  
Shoot Elongation ◽  
Douglas Fir ◽  
Threshold Concentration ◽  
Root Pruning ◽  
Flowering Response ◽  
Seed Cone ◽  
Female Flowering

Shoot elongation and female flowering response were assessed for gibberellin A4/7 (GA4/7) and root-pruning (RP) treatments in 9- and 10-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings of families with good- and poor-flowering histories. In families with a poor-flowering history, stem injections of GA4/7 significantly enhanced elongation of third-whorl terminal shoots but produced no flowering response. In families with a good-flowering history, GA4/7 treatment had no effect on shoot elongation but did result in a significant increase in seed-cone buds. In contrast, root-pruning significantly retarded shoot growth in families with both good- and poor-flowering histories and was also the single most effective treatment for enhancing flowering. Combined, GA4/7 plus RP had a synergistic effect on flowering and GA4/7 partially overcame the inhibition of shoot growth caused by RP alone. These results are consistent with a hypothesis that exogenous and endogenous gibberellins are used preferentially for vegetative growth processes, with increased flowering occurring only after a threshold concentration of effector gibberellins is reached.

Stimulation of flowering by grafted black spruce and white spruce: a comparative study of the effects of gibberellin A4/7, cultural treatments, and environment

1991 ◽  
Vol 21 (3) ◽  
pp. 395-400 ◽  
Author(s):  
Michael S. Greenwood ◽  
Gregory W. Adams ◽  
Michele Gillespie
Keyword(s):  
Black Spruce ◽  
White Spruce ◽  
Shoot Elongation ◽  
Height Growth ◽  
Root Pruning ◽  
Female Cone ◽  
Growth Cycles ◽  
Female Flowering ◽  
Chilling Treatment ◽  
Stimulation Of

Flower stimulation treatments, including gibberellin A4/7 (GA4/7) application, root-pruning, and greenhouse environment during the latter part of shoot elongation, were applied to grafted, clonal black spruce (Piceamariana (Mill.) B.S.P.) and white spruce (Piceaglauca (Moench) Voss) of roughly the same size and age. In addition, the size of pot-grown ramets of both species was increased by inducing additional growth cycles by several applications of a chilling treatment followed by an 18-h photoperiod in a heated greenhouse. This treatment doubled the height growth of both species over a 2-year period, and female cone bud production was promoted by GA4/7. GA4/7 also promoted female flowering on field-grown material, but root-pruning had little effect; black spruce was more responsive to GA4/7 (10× increase) than white spruce (3× increase). Male flowering in black spruce was consistently, and sometimes significantly, inhibited by GA4/7, but was promoted in white spruce. In the latter case the response was not statistically significant. In contrast, male flowering was increased in potted trees of both species by allowing shoots to elongate 50–75% outdoors, after which the trees were moved into a greenhouse.

Interaction between gibberellin A4/7 and root-pruning on the reproductive and vegetative processes in Douglas-fir. IV. Effects on lateral bud development

1986 ◽  
Vol 16 (2) ◽  
pp. 211-221 ◽  
Author(s):  
J. N. Owens ◽  
J. E. Webber ◽  
S. D. Ross ◽  
R. P. Pharis
Keyword(s):  
Normal Development ◽  
Shoot Elongation ◽  
Douglas Fir ◽  
Root Pruning ◽  
Lateral Shoot ◽  
Bud Development ◽  
Lateral Bud ◽  
Mitotic Frequency ◽  
Bud Initiation ◽  
Vegetative Bud

The anatomy, mitotic frequency, size, and total insoluble carbohydrate histochemistry was studied in axillary apices from 9- and 10-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) trees after cone induction treatments of root-pruning and (or) stem injections of a gibberellin A4 and A7 (GA4/7) mixture. Axillary buds were initiated at the time of root-pruning, but root-pruning treatment had no effect on axillary bud initiation. Axillary apices from control and gibberellin-treated trees were similar and followed the normal sequence of bud-scale initiation, differentiation, and leaf initiation (described previously) and no cone buds differentiated. Early development of axillary apices from root-pruned and root-pruned, gibberellin-treated trees was normal, but development became retarded near the time of vegetative bud flush. Retarded apices were small with low mitotic frequency and developed many features characteristics of latent apices. Retardation of axillary apices continued until mid-July when normal development resumed and apices differentiated into reproductive buds or vegetative buds, or became latent. The trees in which the greatest retardation of apical development occurred during lateral shoot elongation produced the most cone buds. These results are discussed in relation to hypotheses proposed to explain how cultural and gibberellin treatments affect cone induction in the Pinaceae.

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.

Promotion of flowering in young Larixlaricina grafts by gibberellin A4/7 and root pruning

1990 ◽  
Vol 20 (9) ◽  
pp. 1448-1452 ◽  
Author(s):  
Throstur Eysteinsson ◽  
Michael S. Greenwood
Keyword(s):  
Plant Growth ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Shoot Elongation ◽  
Root Pruning ◽  
Mature Trees ◽  
Foliar Sprays ◽  
Female Flowering

Flowering was promoted on potted, indoor, and field-grown 3-year-old juvenile and mature Larixlaricina (Du Roi) K. Koch grafts by foliar sprays of the plant-growth regulator gibberellin A4/7 and root pruning. Biweekly gibberellin A4/7 applications of three different durations, commencing at the start of long-shoot elongation, yielded similar increases in female flowering in the greenhouse; this effect was synergistically enhanced by root pruning. Male flowering was promoted by gibberellin A4/7 + root pruning in mature but not juvenile grafts. In the field, female flowering was also promoted by the gibberellin A4/7 treatment commencing at the start of shoot extension, but gibberellin A4/7 applications starting later were not effective. Grafted scions from mature trees responded significantly better to gibberellin A4/7 + root pruning than did seedling scions.

Morphological Effects of Root Pruning and Wrenching White Spruce Transplants

1988 ◽  
Vol 5 (4) ◽  
pp. 245-247
Author(s):  
Lisa J. Buse ◽  
Robert J. Day
Keyword(s):  
Growing Season ◽  
White Spruce ◽  
Shoot Elongation ◽  
Diameter Growth ◽  
Root Pruning ◽  
Fibrous Root ◽  
Root Collar Diameter ◽  
Collar Diameter ◽  
Root Collar

Abstract The principal objective of this research was to evaluate the effect of root pruning followed by wrenching on the morphological quality of 2 + 2 white spruce transplant stock during the final year on the nursery. In 1984, white spruce transplants were root pruned: (1) before shoot elongation; (2) during elongation; and (3) after elongation, followed by root wrenching at 28-day intervals until September (4, 3, and 2 times, respectively). In 1985, similar stock was root pruned before shoot elongation and (1) root wrenched at 21-day intervals (4 times), and (2) root wrenched periodically (twice). In both years, height and root collar diameter growth were monitored throughout the season. In the fall, morphological quality was assessed and bud samples were collected to determine the effects of root conditioning on primordia development. Root conditioning modified the morphology of stock in both years by reducing height and root collar diameter and inducing the development of a compact fibrous root system. Early season root pruning followed by wrenching at regular intervals throughout the growing season had the most effect on shoot and root morphology. Differences in results between years were attributed to environment. North. J. Appl. For. 5:245-247, December 1988.

WHITE SPRUCE AND THE SPRUCE BUDWORM: DEFINING THE PHENOLOGICAL WINDOW OF SUSCEPTIBILITY

1997 ◽  
Vol 129 (2) ◽  
pp. 291-318 ◽  
Author(s):  
Robert K. Lawrence ◽  
William J. Mattson ◽  
Robert A. Haack
Keyword(s):  
Picea Glauca ◽  
High Performance ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
White Spruce ◽  
Shoot Elongation ◽  
Larval Survival ◽  
Strongly Correlated ◽  
Negative Effect ◽  
Foliar Traits

AbstractSynchrony of insect and host tree phenologies has often been suggested as an important factor influencing the susceptibility of white spruce, Picea glauca (Moench) Voss, and other hosts to the spruce budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae). We evaluated this hypothesis by caging several cohorts of spruce budworm larvae on three white spruce populations at different phenological stages of the host trees, and then comparing budworm performance with host phenology and variation of 13 foliar traits. The beginning of the phenological window of susceptibility in white spruce occurs several weeks prior to budbreak, and the end of the window is sharply defined by the end of shoot growth. Performance was high for the earliest budworm cohorts that we tested. These larvae began feeding 3–4 weeks prior to budbreak and completed their larval development prior to the end of shoot elongation. Optimal synchrony occurred when emergence preceded budbreak by about 2 weeks. Larval survival was greater than 60% for individuals starting development 1–3 weeks prior to budbreak, but decreased to less than 10% for those starting development 2 or more weeks after budbreak and thus completing development after shoot elongation ceased. High performance by the budworm was most strongly correlated with high levels of foliar nitrogen, phosphorous, potassium, copper, sugars, and water and low levels of foliar calcium, phenolics, and toughness. These results suggest that advancing the usual phenological window of white spruce (i.e. advancing budbreak prior to larval emergence) or retarding budworm phenology can have a large negative effect on the spruce budworm’s population dynamics.

scholarly journals Effective Early Treatment of AChR Antibody-Positive Myasthenia Gravis with Rituximab; the Experience from a Neuroimmunology Clinic in a Developing Country

2021 ◽  
Vol 13 ◽  
pp. 117957352110160
Author(s):  
Thomas Mathew ◽  
Kurian Thomas ◽  
Saji K John ◽  
Shruthi Venkatesh ◽  
Raghunandan Nadig ◽  
...  
Keyword(s):  
Observational Study ◽  
Myasthenia Gravis ◽  
Treatment Option ◽  
Early Treatment ◽  
Early Stage ◽  
Tertiary Care ◽  
Response To Treatment ◽  
Myasthenic Crisis ◽  
Achr Antibody ◽  
Significant Difference

Background: Rituximab is reserved for treating refractory myasthenia gravis (MG) patients. Here we report our experience with rituximab in AChR antibody positive generalized MG (gMG) and impending myasthenic crisis (IMC). Methods: This retrospective, observational study, conducted at a tertiary care, neuroimmunology clinic, analyzed the data of patients with AChR antibody positive gMG, treated with rituximab between 1st January 2016 and 30th October 2018. Results: Eleven patients with AChR antibody positive gMG received rituximab. Mean age of the cohort was 50.54 ± 18.71 years with 9 males. Seven out of 11 patients received rituximab in the early stage (<2 years from onset) and had good response to treatment. Four of the 5 patients with IMC improved with rituximab alone. In the 10 patients who regularly followed up, there was a significant difference between the QMG scores at baseline and at 1, 2, 6, 12, and 18 months ( P < .0001). Conclusion: Rituximab appears to be a potentially effective early treatment option for AChR antibody positive generalized MG and impending myasthenic crisis.

Gibberellin A4/7 enhances seed-cone production in field-grown black spruce

1988 ◽  
Vol 18 (1) ◽  
pp. 139-142 ◽  
Author(s):  
Rong H. Ho
Keyword(s):  
Vitamin E ◽  
Black Spruce ◽  
Seed Orchard ◽  
Shoot Elongation ◽  
Bud Burst ◽  
Lateral Shoot ◽  
Cone Production ◽  
Seed Cone ◽  
Vegetative Bud ◽  
Needle Primordia

Black spruce (Piceamariana (Mill.) B.S.P.) grafts growing in a seed orchard were sprayed with gibberellin A4/7, and grafts and trees in families growing in arboreta were sprayed with gibberellin A4/7 and (or) vitamin E from vegetative bud burst to the end of shoot elongation. Gibberellin A4/7 was very effective in promoting seed cones and 400 mg/L appeared optimal. Vitamin E at 1000 mg/L was not effective. Vegetative bud burst occurred in mid-May and shoot elongation ended in late June. Needle primordia were visible on the apices of newly formed buds at the end of June. Reproductive buds had fewer bud scales than vegetative buds. It appeared that potential reproductive buds terminated their bud scale initiation earlier. Gibberellin A4/7 application to promote seed-cone production should be carried out before bud-type differentiation. This coincides with the end of lateral shoot elongation.

scholarly journals Collision Tumors of the Cervix – A Case Series: Its Clinical Significance in the Management of an Early Stage Disease

2018 ◽  
Vol 52 (6) ◽  
Author(s):  
Jimmy A. Billod ◽  
Efren J. Domingo
Keyword(s):  
Cervical Cancer ◽  
Recent Literature ◽  
Early Stage ◽  
Case Series ◽  
Response To Treatment ◽  
Clinicopathologic Features ◽  
Early Stage Disease ◽  
Collision Tumors ◽  
Stage Disease ◽  
Histologic Types

Majority of cervical cancer are squamous cell carcinoma and adenocarcinoma. The co-existence of two histologic types is rare. This article presents three cases of collision tumors of the cervix within a 10-year review. All underwent radical hysterectomy for an early stage disease. Likewise, it aims to review clinicopathologic features, management, response to treatment and prognosis of these types of tumor in the light of recent literature.

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