Syllepsis in Larixlaricina: analysis of tree leaders with and without sylleptic long shoots

1987 ◽  
Vol 17 (6) ◽  
pp. 490-498 ◽  
Author(s):  
G. R. Powell
Keyword(s):  
Developmental Pathways ◽  
Lateral Buds ◽  
Long Shoots ◽  
Short Shoots ◽  
Terminal Buds ◽  
Lateral Axis

Nonsylleptic and lightly, moderately, and heavily sylleptic leaders with 0 and 1–8, 9–17, and 18–38 sylleptic long shoots, respectively, were cut from 8-year-old Larixlaricina (Du Roi) K. Koch trees. The leaders showed considerable crookedness but degrees of crookedness were not significantly different among leader classes. Leaders of all classes bore sylleptic short shoots. These sylleptic short shoots were largest at midleader locations and larger on leaders with sylleptic long shoots than on nonsylleptic leaders. The terminal buds on many sylleptic short shoots were of long-shoot type. Some sylleptic short shoots with such buds occurred in mid- and proximal-leader positions, whereas lateral buds of the long-shoot type occurred only in distal-leader positions. Sylleptic long and short shoots greatly increased the numbers of leaves on the leaders. This leaf increase occurred principally on the proximal halves of the leaders where leader diameters also increased. Larger amounts of xylem accounted for most of the diameter increases. Subtending leaf to lateral axis distances increased acropetally among lateral buds and sylleptic shoots, but for the latter, these distances were greatest in the middle parts of the respective zones of occurrence. The large variety of developmental pathways for lateral axes on leaders was discussed.

Crown architecture of Larix laricina saplings: an analysis of higher order branching

1987 ◽  
Vol 65 (2) ◽  
pp. 268-279 ◽  
Author(s):  
W. R. Remphrey ◽  
G. R. Powell
Keyword(s):  
Simulation Modelling ◽  
Shoot Length ◽  
Larix Laricina ◽  
Structural Development ◽  
Short Shoot ◽  
Lateral Buds ◽  
Architectural Patterns ◽  
Long Shoots ◽  
Short Shoots ◽  
Terminal Shoot

Quantitative analysis and simulation modelling of Larix laricina (Du Roi) K. Koch branches revealed a complex system of architectural patterns and correlations. Numbers of lateral buds and long shoots were positively correlated with parent-shoot length, but the relationships varied among shoot orders and for sylleptic shoots. For order 2 and sylleptic shoots, numbers of lateral long shoots were also correlated with associated terminal-shoot lengths. Sylleptic shoots produced more lateral long shoots than equivalent proleptic shoots. Lateral long-shoot lengths decreased basipetally and were correlated with terminal-shoot lengths. Lengths of order 2 lateral long shoots also varied independently with crown position. Generally, the degree of apical control decreased and the proportion of short shoots increased with positions of less vigour in the crown. Terminal long-shoot lengths varied with parent-shoot length, location, and to some extent parent-axis leader length. Terminal short-shoot production was associated with shorter parent shoots. Shorter order 2 shoots (<60 mm) and most order 3 shoots produced no lateral long shoots. The net result was that branch structural development ceased in less vigorous crown positions. The spatial disposition of shoots, as defined by elevation and divergence angles, varied with position of origin around and along parent shoots. Although variable, elevation angles decreased and divergence angles increased basipetally.

An architectural analysis of Shepherdia canadensis and Shepherdia argentea: patterns of shoot development

1989 ◽  
Vol 67 (6) ◽  
pp. 1870-1877 ◽  
Author(s):  
P. A. Hayes ◽  
T. A. Steeves ◽  
B. R. Neal
Keyword(s):  
Seasonal Pattern ◽  
Shoot Development ◽  
Distinct Pattern ◽  
Bud Burst ◽  
Internodal Length ◽  
Architectural Analysis ◽  
Lateral Buds ◽  
Long Shoots ◽  
Short Shoots ◽  
Shepherdia Canadensis

In the context of an architectural analysis, the seasonal pattern of shoot development of Shepherdia canadensis and S. argentea (Elaeagnaceae) was examined. In both species floral bud burst was the first outward manifestation of seasonal activity. Vegetative shoots of S. canadensis expanded 3 – 5 pairs of preformed leaves during a period of 9 – 10 weeks. There was no pattern of internodal length that identified annual increments. In S. argentea, 6 – 18 pairs of leaves expanded during a period of 15 – 17 weeks, the variation being related to the extent of neoformation. There was a distinct pattern of internodal length, with a maximum in midseason, so that annual increments could be recognized subsequently. Lateral buds in S. canadensis expanded only proleptically as either short shoots or long shoots. Most had declining growth rates in the subsequent year and within 5 to 7 years had undergone abscission. In S. argentea. lateral buds expanded both sylleptically and proleptically as short shoots, long shoots, or thorns. The distribution pattern of these lateral types was related to the vigour of parent shoot growth. Some abscission of short shoots was noted. For each species a stochastic flow chart of shoot development was prepared and a computer program incorporating actual data was written that simulated shoot development for up to four generations of growth. Comparison of the two species indicates that S. argentea is more plastic in response to environmental conditions.

Crown architecture of Larix laricina saplings: shoot preformation and neoformation and their relationships to shoot vigour

1984 ◽  
Vol 62 (11) ◽  
pp. 2181-2192 ◽  
Author(s):  
W. R. Remphrey ◽  
G. R. Powell
Keyword(s):  
Leaf Primordia ◽  
Shoot Length ◽  
Larix Laricina ◽  
Crown Architecture ◽  
Short Shoot ◽  
Shoot Buds ◽  
Lateral Buds ◽  
Lateral Bud ◽  
Long Shoots ◽  
Terminal Buds

Resting buds from five locations on long shoots in each of six crown positions were compared for 30 Larix laricina (Du Roi) K. Koch saplings. At each locus, bud sizes, numbers of bud scales and preformed leaf primordia (basal and axial for long-shoot buds), and apical widths were positively related to parent-shoot length. Along individual shoots, (i) terminal and lateral long-shoot buds contained fewer basal-leaf primordia than the more proximal short-shoot buds; (ii) terminal buds contained the most bud scales and axial-leaf primordia; and (iii) numbers of bud scales increased, while numbers of axial-leaf primordia generally decreased, basipetally among lateral buds. Comparison of bud leaf content with leaves on elongated shoots by regression showed that numbers of preformed and neoformed leaves increased with shoot length, but numbers of neoformed leaves did so to a greater degree. Internode lengths, numbers of leaves per lateral bud produced, and leaf lengths were greater on neoformed than on preformed shoot segments. Because of their capacity for neoformed growth following preformed growth and because of increases in internode lengths among all axial leaves, shoots from subjacent lateral buds replaced experimentally decapitated tree leaders (terminal buds) in one season, with little or no loss of height growth.

Compensatory shoot growth in young black birch and red maple trees

1993 ◽  
Vol 23 (2) ◽  
pp. 302-306 ◽  
Author(s):  
Brayton F. Wilson
Keyword(s):  
Compensatory Growth ◽  
Shoot Growth ◽  
Shoot Length ◽  
Red Maple ◽  
Single Treatment ◽  
Frequency Distributions ◽  
Lateral Buds ◽  
Long Shoots ◽  
Short Shoots ◽  
Whole Tree

Black birch (Betulalenta L.) and red maple (Acerrubrum L.) trees 1.5–2 m tall responded by compensatory (increased) shoot growth following a single treatment where shoots on the whole tree were clipped. Total shoot length of clipped trees recovered to control levels after 1 year's growth. The remaining buds on clipped shoots grew more than they would have without clipping. Frequency distributions of shoot lengths shifted toward longer lengths in clipped trees in the 1st year, but were similar to controls 2 years after clipping. The longest shoots were as long, or longer, on clipped shoots as on unclipped shoots. The major compensatory growth mechanism was increased growth of lateral buds. Clipping induced a few preventi-tious buds to form shoots and a few unclipped short shoots to grow as long shoots.

scholarly journals Correlations among lateral shoots in young apple trees

2015 ◽  
Vol 28 (1) ◽  
pp. 131-149 ◽  
Author(s):  
H. Pilich ◽  
L. S. Jankiewicz ◽  
Bożena Borkowska ◽  
Alicja Moraszczyk
Keyword(s):  
Dry Weight ◽  
Feedback Mechanism ◽  
Special Treatment ◽  
Medium Size ◽  
Apple Trees ◽  
Lateral Buds ◽  
Long Shoots ◽  
Positive Feedback Mechanism ◽  
Short Shoots ◽  
One Year

Growth correlations among axillary buds and young shoots in one-year-old apple trees were investigated. Darkening of every second bud for 3-5 days during bursting time resulted in the formation of mainly short shoots. Thinning of part of the buds caused a higher percentage of the remaining ones to form long shoots. High nutrition level favored the formation of long shoots. When no special treatment was given to the trees, the initial size of the buds played an important role in the determination of future shoot vigor. The medium-size and large buds, in most cases, showed an ability to accumulate more <sup>32</sup>PO<sup>3-</sup><sub>4</sub> per unit of dry weight than did the smaller ones. This indicates that the initial differences among the buds are amplified by a positive feedback mechanism. In horizontally placed trees, the buds on the lower side showed inhibited phosphate uptake. Different growth regulators applied in very small amounts, in a droplet of water to every second bud or shoot tip, markedly changed the correlative interrelations among the developing shoots. The development of vascular connections between the main axis and the lateral buds and shoots of different sizes was investigated.

Annual cycle of shoot development in sugar maple

1980 ◽  
Vol 10 (3) ◽  
pp. 316-326 ◽  
Author(s):  
Robert A. Gregory
Keyword(s):  
Annual Cycle ◽  
Sugar Maple ◽  
Growing Season ◽  
Shoot Formation ◽  
Shoot Development ◽  
Bud Formation ◽  
Terminal Bud ◽  
Long Shoots ◽  
Short Shoots ◽  
Terminal Buds

Cytohistology and the development and morphogenesis of sugar maple (Acersaccharum Marsh.) shoots were studied. Three types were recognized: short shoots, long shoots entirely preformed in the bud (Epf long), and long shoots partially preformed in the bud (heterophyllous). The three shoot types varied not only in the size and number of internodes and leaves but also in the development of terminal buds. Terminal bud formation was delayed in heterophyllous shoots but because of a shorter plastochron, which extended later into the growing season, the terminal apices of these shoots were able to annually produce more primordia than in other shoot types. The beginning of embryonic shoot formation, however, began about the same time (late July) for all shoot types.

SEASONAL GROWTH CHARACTERISTICS OF LONG AND SHORT SHOOTS OF TAMARACK

1967 ◽  
Vol 45 (9) ◽  
pp. 1643-1651 ◽  
Author(s):  
J. Johanna Clausen ◽  
T. T. Kozlowski
Keyword(s):  
Seasonal Changes ◽  
Stem Elongation ◽  
Growth Characteristics ◽  
Weight Increase ◽  
Stem Length ◽  
Larix Laricina ◽  
Seasonal Growth ◽  
Long Shoots ◽  
Short Shoots ◽  
Food Reserves

Tamarack (Larix laricina (DuRoi) K. Koch) produces long shoots which bear two kinds of needles. Early needles are present in the bud and elongate rapidly after budbreak. Late needles, few of which are present in the bud, elongate later than early needles. Short shoots bear early needles only, and stem length seldom exceeds 1 mm. Seasonal changes in length and weight of needles and stems of both shoot types were measured. In long shoots, 75% of stem elongation, more than 70% of stem weight increment, and 65–70% of late needle elongation occurred after early needles were full-sized. Stem and late needle elongation ceased simultaneously, after which time needle weight decreased and stem weight increased. Early needles probably drew on food reserves while developing, and then themselves contributed to stem and late needle elongation. Final stem weight increase probably used photosynthate from both late and early needles of the current year.Shading of current and last year's needles showed that shoots in which photosynthesis was interrupted in this way produced shorter, lighter-weight stems than did control shoots.

Spatial distribution and morphology of shoots in the variant crown form of Rhododendron reticulatum

Botany ◽  
2010 ◽  
Vol 88 (11) ◽  
pp. 995-1005 ◽  
Author(s):  
Kenichi Yoshimura
Keyword(s):  
Spatial Distribution ◽  
Functional Differentiation ◽  
Forest Understory ◽  
Width Ratio ◽  
Crown Architecture ◽  
Western Japan ◽  
Long Shoots ◽  
Short Shoots ◽  
Lower Depth ◽  
Crown Form

Rhododendron reticulatum D. Don ex G.Don is a common understory shrub in western Japan that exhibits highly plastic crown architecture and occurs in various light environments. I investigated how functional differentiation and spatial distribution of long and short shoots contribute to the plasticity of crown architecture of R. reticulatum. Crown form was derived from the crown depth/width ratio. Crown depth/width ratio was higher in sun-lit crowns. In crowns with higher depth/width ratio, long shoots were distributed in upper positions of the crown. Long shoots grew vertically and horizontally. In crowns with lower depth/width ratio, long shoots were arranged in the outer position of the crown and grew outward. Within neighboring shoots, long shoots had less mass than their paired short shoots. Results suggest that long shoots of R. reticulatum function to expand the crown and to reduce leaf overlap in multilayer crowns, which are found in high-light environments, while both long and short shoots function to minimize leaf overlap in monolayer crowns, which are found in shaded environments. Plasticity of crown architecture by altering shoot position and shoot morphology allows growth under various light environments in the forest understory.

Leaf area development on different shoot types in a young aspen stand and its effect upon production

1970 ◽  
Vol 48 (10) ◽  
pp. 1801-1804 ◽  
Author(s):  
D. F. W. Pollard
Keyword(s):  
Leaf Area ◽  
Total Production ◽  
Short Shoot ◽  
Area Index ◽  
Young Leaves ◽  
Long Shoots ◽  
Short Shoots ◽  
Area Development ◽  
Leaf Area Development ◽  
Photosynthetic Efficiencies

Different shoot types in aspen crowns carried leaves of different ages; leaders continued to produce leaves until early August and always carried some young leaves, whereas short shoots completed development by mid-June. Development of foliage on long shoots was intermediate between that on leaders and short shoots. Leaf area index of the 6-year-old stand reached a maximum of 2.4, of which 2.1 was contributed by short-shoot foliage. The rest was formed by leaders and long shoots. Young leaves on leaders and long shoots were not sufficient to influence total production in the stand appreciably, even though young aspen leaves may have high photosynthetic efficiencies. These young leaves could, however, influence height growth and lateral development of the canopy.

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