Seedling Shoot and Bud Development in Provenances of Sitka Spruce, Piceasitchensis (Bong.) Carr.

1975 ◽  
Vol 5 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Douglas F. W. Pollard ◽  
Abraham H. Teich ◽  
Kenneth T. Logan
Keyword(s):  
Growth Rate ◽  
Induction Period ◽  
Growth And Development ◽  
Shoot Growth ◽  
Shoot Elongation ◽  
Sitka Spruce ◽  
Bud Development ◽  
The Third ◽  
Terminal Bud ◽  
Needle Primordia

Growth and development of seedlings of ten provenances were compared in three investigations. The provenances ranged from Oregon to south-east Alaska and were collected for the I.U.F.R.O. International Sitka Spruce Provenance Experiment. The potential for seedling growth was studied by measuring (a) the rate of shoot growth and (b) the duration of shoot elongation. Growth rate was rather uniform, being only slightly faster among northern provenances. The duration of shoot growth, under artificial declining photoperiods was strongly influenced by latitude of origin. The critical photoperiods necessary for sustained growth in southern provenances were up to 4 hours shorter than those in northern provenances. In the third investigation development of the terminal bud was followed during the first 8 weeks. After a 4-week induction period buds attained macroscopic sizes with ca. 100 needle primordia. Northern provenances had up to 65% more primordia than southern ones. At 8 weeks, a strong but reversed relationship was evident, with southern provenances having up to 35% more than northern provenances. These observations indicate that latitude-correlated variations will be an important feature of the I.U.F.R.O. Experiment, with southern provenances performing especially well in southern trials. Potential advantages of southern provenances will be protracted periods of shoot growth in young seedlings and protracted periods of development of the primordial shoot in overwintering buds. However, where summer seasons are short, such advantages may not be realized.

Growth and development of larvae and adults of Tipula sacra Alexander (Insecta: Diptera) in a series of abandoned beaver ponds

1976 ◽  
Vol 54 (2) ◽  
pp. 266-284 ◽  
Author(s):  
G. Pritchard
Keyword(s):  
Growth Rate ◽  
Life History ◽  
Growth And Development ◽  
Adult Emergence ◽  
Head Capsule ◽  
Fourth Instar ◽  
Beaver Ponds ◽  
The Third ◽  
First Instar ◽  
Two Peaks

Collections of all stages of the crane fly, Tipula sacra have been made over a period of years from a series of abandoned beaver ponds in the Kananaskis Valley, Alberta. The growth of larvae was followed by head-capsule measurements and weights. Eggs hatch within a month; first-instar larvae grow rapidly and enter the second instar after a few weeks. The second instar may last for 3 months and the third instar usually lasts for 6 months, including the first winter. Most larvae spend almost a full year in the fourth instar and overwinter for a second time. However, there was much variation in growth rate within the population. Adult emergence curves were consistent in form in 4 years. Each spanned a period of just over 2 months, although individual adults lived for only a few days. These curves snowed two peaks, the second of which contained 15–20% of the year's emergents. These two groups may represent different cohorts that have grown at different rates, suggesting that the life history may be semivoltine or univoltine. The sex ratio changes from about 1:1 in the third instar to 2:1 in favor of males in the late fourth instar, pupa, and adult.

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 Shifts in Bud and Leaf Hardiness during Spring Growth and Development of the Cranberry Upright: Regrowth Potential as an Indicator of Hardiness

2006 ◽  
Vol 131 (3) ◽  
pp. 327-337 ◽  
Author(s):  
Beth Ann A. Workmaster ◽  
Jiwan P. Palta
Keyword(s):  
Nonlinear Regression ◽  
Stress Resistance ◽  
Growth And Development ◽  
Cold Hardiness ◽  
Freezing Stress ◽  
Critical Temperatures ◽  
Bud Development ◽  
Air Temperatures ◽  
Terminal Bud ◽  
Bud Growth

`Stevens' cranberry (Vaccinium macrocarpon Ait.) terminal bud freezing stress resistance was assessed by nonlinear regression utilizing relative scoring of the post-thaw bud growth and development based on defined bud stages 2 weeks following controlled freezing tests. Bud stages tested were chosen based on a phenology profile from each sampling date throughout the spring season. Previous year (overwintering) leaf freezing stress resistance was evaluated after both 2 days (injury) and 2 weeks (survival). The Gompertz function with a bootstrapping method was used to estimate the tissues' relative freezing stress resistance as the LT50. Bud injury levels (LT50) were expressed as the temperatures at which the mean potential regrowth capability was impaired by 50%, as compared with the unfrozen controls. In leaves, the LT50 is the temperature at which 50% injury (2-day evaluation) or survival (2-week evaluation) was modeled to occur. Dramatic changes in terminal bud relative freezing stress resistance occurred both within and between the tight and swollen bud stages. These results clearly show that seasonal changes in freezing stress resistance do not necessarily parallel changes in crop phenology and bud development. These results indicate that some physiological, biochemical, or fine anatomical changes may explain the seasonal loss in hardiness within a visual bud stage. Previous year leaves may possess the ability to recover from freeze-induced injury, as leaf survival was found to be the most reliable indicator of cranberry leaf hardiness. Major shifts in phenology and bud and leaf hardiness coincided with the rise of minimum canopy-level air temperatures to above freezing. The nonlinear regression technique utilized made it possible to estimate LT50 with data points comprising half or more of the sigmoidal dose response curve. Our study provides precise and quantitative estimates of the cold hardiness changes in cranberry terminal buds and leaves in spring. From precise estimates we were able to define critical temperatures for the impairment of cranberry bud growth. This is the first systematic study of cranberry terminal bud cold hardiness and spring bud development in relation to changes in the soil and air temperatures under natural conditions. Our study shows that regrowth assessment of the cranberry upright inherently describes the composite effects of freezing stress on plant health.

Long shoot terminal bud development and the differentiation of pollen- and seed-cone buds in Pinuscaribaea var. hondurensis

1992 ◽  
Vol 22 (11) ◽  
pp. 1656-1668 ◽  
Author(s):  
Derek L.S. Harrison ◽  
Mike U. Slee
Keyword(s):  
Growth Pattern ◽  
Shoot Growth ◽  
Bud Development ◽  
Late Flowering ◽  
Seed Cone ◽  
Terminal Bud ◽  
Caribbean Pine ◽  
Terminal Buds

Bud type differentiation and development were investigated in early and late flowering grafted clones of Pinuscaribaea Morelet var. hondurensis Barr. & Golf. (Caribbean pine) growing at two sites in the tropical north of Australia. Regardless of the early and late flowering tendencies, pollen- and seed-cone buds began to differentiate in middle and late March, respectively. Unlike the cone buds of temperate pines, there was no apparent pause in development between pollination and differentiation. The long shoot terminal bud organogenic sequence resembled that described in temperate pines and led to an episodic, monocyclic shoot growth pattern. The formation of up to several long shoot terminal buds between the onset of seed-cone-bud differentiation and flowering frequently resulted in multiple sets of seed cones.

Timing of defoliation and its effect on bud development, starch reserves, and sap sugar concentration in sugar maple

1986 ◽  
Vol 16 (1) ◽  
pp. 10-17 ◽  
Author(s):  
Robert A. Gregory ◽  
Philip M. Wargo
Keyword(s):  
Sugar Maple ◽  
Shoot Growth ◽  
Sugar Concentration ◽  
Starch Concentration ◽  
Bud Development ◽  
Late Season ◽  
Terminal Bud ◽  
Terminal Shoot ◽  
Terminal Buds ◽  
And Control

Sapling sugar maple (Acersaccharum Marsh.) trees were defoliated artificially at 10-day intervals beginning May 27 and ending August 5, 1981. Refoliation, terminal bud and shoot development, and xylem starch and sap sugar concentration were observed in defoliated and control trees. All defoliated trees refoliated, but decreasingly with later defoliation. Defoliation caused an acceleration in the rate of primordia initiation in terminal shoot apices. After early season defoliations, the developing buds in the axils of the removed leaves abscissed, but axillary and terminal buds on the refoliated terminal shoots survived through winter. In late season defoliation, most buds of refoliated shoots did not survive and the next year's growth depended on axillary buds formed prior to defoliation. Thus, when progressing from early to late defoliations, the next year's shoot growth depended decreasingly on the last-formed and increasingly on the first-formed portions of the previous year's shoot. Early October starch concentration in xylem decreased with later defoliation and was nearly absent in shoots and roots of trees defoliated in late July. There was not, however, a corresponding decrease in sap sugar concentration. Mortality occurred only in late defoliated trees and was associated with starch depletion.

Accumulation and Utilization of Carbohydrate Reserves in Shoot Growth of Pinusresinosa

1973 ◽  
Vol 3 (3) ◽  
pp. 346-353 ◽  
Author(s):  
M. O. Olofinboba ◽  
T. T. Kozlowski
Keyword(s):  
Shoot Growth ◽  
Shoot Elongation ◽  
Bud Development ◽  
Carbohydrate Reserves ◽  
Late Season ◽  
Phloem Translocation ◽  
Food Reserves

Evidence is presented which emphasizes the importance of food reserves and conditions controlling late-season photosynthesis (e.g. during bud development) to subsequent-year shoot growth ofPinusresinosa. By the end of August, after shoot elongation ceased, current 14C-photosynthate was mobilized by roots, stems, and twigs. Much of the currently produced photosynthate accumulated as reserves in roots, stems, and twigs. When phloem blocks were applied in March behind the prior-year internode of defoliated shoots, thereby preventing phloem translocation of currently produced photosynthate from old needles to the buds, considerable shoot expansion still occurred, indicating utilization of reserve photosynthates of the prior-year internode.

scholarly journals SHOOT GROWTH AND DEVELOPMENT OF `STARKSPUR SUPREME DELICIOUS' VARIES WITH ROOTSTOCK.

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1111f-1111
Author(s):  
Curt R. Rom
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Shoot Growth ◽  
Leaf Size ◽  
Dry Weight ◽  
Shoot Length ◽  
Internode Length ◽  
Terminal Bud ◽  
Shoot Growth Rate ◽  
Old Trees

Shoot growth `Starkspur Supreme Delirious' on 10 different rootstock was measured on 3-, 4- and 6-year-old trees at weekly intervals from budbreak until terminal bud formation. Spur density, spur development, and extension shoot leaf area development were measured in September. Growth rate was analyzed by regression against chronological time and accumulated growing degree days using linear and nonlinear statistics.Rootstock affected shoot length, leaf number, leaf area, leaf size, leaf dry weight/leaf area and internode length. Trees on M.4, M.7 EMLA, P-1 and seedling had the longest shoots and highest shoot growth rate. Trees on P16 had least leaves and leaf area per shoot and smallest shoot leaves. Leaf dry wt./area were negatively correlated to leaf size. Typically, trees with shortest shoot length and smallest internode length had greatest spur density. Rootstock affected both rate and duration of shoot growth. Shoots on trees with P22 and P2 rootstocks grew for the shortest duration while trees on M.4 and M.7 EMLA grew for the longest period.

Bud development in Picea glauca. I. Annual growth cycle of vegetative buds and shoot elongation as they relate to date and temperature sums

1977 ◽  
Vol 55 (21) ◽  
pp. 2728-2745 ◽  
Author(s):  
John N. Owens ◽  
Marje Molder ◽  
Hilary Langer
Keyword(s):  
Picea Glauca ◽  
Shoot Growth ◽  
Shoot Elongation ◽  
Growth Cycle ◽  
Bud Dormancy ◽  
Annual Growth ◽  
Bud Development ◽  
Leaf Initiation ◽  
Vegetative Buds ◽  
Vegetative Bud

Vegetative buds of Picea glauca (Moench) Voss were studied throughout the annual growth cycle in several trees in 1975 and 1976 and bud development was related to lateral vegetative shoot growth, date, and temperature sums.Vegetative buds became mitotically active in mid-April at lower elevations and about 6 weeks later at higher elevations. Shoot elongation was characterized by similar smooth sigmoid curves in both years. Shoot growth was slow for the 1st month, rapid during the 2nd month, and slow again for the 3rd month and ended by early August. Temperature sums related best to percentage of shoot elongation if the end of vegetative bud dormancy was used as the starting date and 5 °C was used as the threshold temperature. Arbitrarily chosen starting dates and threshold temperatures gave temperature sums which were related to shoot elongation only when shoot elongation was nearly completed. Generally, if the end of vegetative bud dormancy is known, the number of days from that time is nearly as accurate as the more complex use of temperature sums in predicting the percentage of shoot elongation or the stage of vegetative bud development.Bud-scale initiation occurred during shoot elongation. Axillary buds were initiated in mid-May and flushing occurred when shoots had elongated to about 30% of their final length in late May or early June. The end of shoot elongation coincided with the onset of leaf initiation on all trees in both years. The change from bud-scale initiation to leaf initiation was preceded by a marked increase in apical width and a slight increase in apical height and mitotic frequency. Leaf initiation was rapid for 6 weeks then slower for the last 4 weeks. Vegetative buds became dormant in mid-October.Vegetative bud development is closely related to shoot elongation. Breaking of vegetative bud dormancy was not affected by temperature but shoot elongation and flushing were affected by temperatures which occurred after dormancy was broken.

Water relations, cuticular transpiration, and bud characteristics of air-slit containerized Picea glauca seedlings in response to controlled irrigation regimes

2001 ◽  
Vol 31 (12) ◽  
pp. 2200-2212 ◽  
Author(s):  
Debra C Stowe ◽  
Mohammed S Lamhamedi ◽  
Hank A Margolis
Keyword(s):  
Picea Glauca ◽  
Maximum Modulus ◽  
Water Relation ◽  
Irrigation Regime ◽  
Seedling Morphology ◽  
Cuticular Transpiration ◽  
Bud Development ◽  
Irrigation Regimes ◽  
Terminal Bud ◽  
Needle Primordia

White spruce seedlings (Picea glauca (Moench) Voss) were grown in air-slit containers (IPL 25-350A) in a tunnel under four different irrigation regimes (IR-15%, IR-30%, IR-45%, and IR-60%, v/v; (cm H2O)3·(cm substrate)–3). At the end of the first growing season the water-relation variables of the shoots were determined. Seedling morphology, the rates of cuticular transpiration and terminal bud development, as well as the number of needle primordia were also measured. Irrigation regime had no significant effect on any of the water-relation variables. Seedlings grown under the IR-15% were smaller and completed bud development more quickly than seedlings grown under IR-30%, IR-45%, and IR-60%. The formation of needle primordia was enhanced under IR-30%. Both the irrigation regime and the amount of time the detached shoots were left to transpire had a significant effect on the rate of cuticular transpiration. A comparison of the water-relation variables at the end of the first (1998) and second (1999) growing seasons showed that the younger seedlings had more negative osmotic potential at tissue saturation and greater maximum modulus of elasticity values. None of the other water-relation variables were significantly affected by seedling age, but the absolute values of all the variables were greater in the younger (1+0) seedlings.

Heat tolerance of actively growing, bud-initiated, and dormant black spruce seedlings

1988 ◽  
Vol 18 (9) ◽  
pp. 1103-1105 ◽  
Author(s):  
R. S. Koppenaal ◽  
S. J. Colombo
Keyword(s):  
Heat Tolerance ◽  
Shoot Growth ◽  
Black Spruce ◽  
Test Chamber ◽  
Shoot Elongation ◽  
First Year ◽  
Main Shoot ◽  
Bud Development ◽  
Environmental Test ◽  
Heat Tolerant

To determine the effect of stage of bud development on heat tolerance, overwintered black spruce seedlings (Piceamariana (Mill.) B.S.P.) were (i) maintained in a dormant state, (ii) allowed to grow new shoots under favorable greenhouse conditions, or (iii) induced to initiate bud scales using short-photoperiod treatment following a period of new shoot elongation. Seedlings of the three shoot types were then exposed for 10 min to temperatures of 25, 42, 45, 50, or 55 °C in an environmental test chamber. Damage to the current-year shoot was lower in bud-initiated seedlings than in active seedlings, particularly at 42 °C, when 0 and 46%, respectively, of the length of the main shoot was damaged. The current-year shoot growth was much more sensitive to heat stress than the lignified first-year shoot, and therefore dormant seedlings, which had only first-year shoot growth, were most heat tolerant, showing damage only at 50 and 55 °C.

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