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: 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.

Origin of the summer shoot of pinyon pines

1970 ◽  
Vol 48 (10) ◽  
pp. 1759-1765 ◽  
Author(s):  
Ronald M. Lanner
Keyword(s):  
Shoot Development ◽  
Two Stage ◽  
Dormant Bud ◽  
Terminal Bud ◽  
Long Shoots ◽  
Stage Process ◽  
Short Shoots ◽  
Lateral Branches

Shoot development in pines is usually a two-stage process, with buds formed in the summer and elongation delayed until the next spring. Summer shoots have been described which originate by precocious elongation of a bud, a process which may or may not be followed by organization of a new dormant bud. However, in several of the pinyon pines, and perhaps in other soft pines as well, summer shoots are formed without having first been present as a bud. These summer shoots are composed partially of internodes associated with terminal bud scales of the previous year, but mainly of internodes initiated and elongated concurrently in the spring and summer. The major lateral branches of the complex shoot have their origin in the summer shoots, laterals of the spring shoot apparently being inhibited. Short shoots and long shoots of the summer shoot have developmental schedules that contrast with those of the spring shoot.

An architectural analysis of Shepherdia canadensis and Shepherdia argentea (Elaeagnaceae): the architectural models

1990 ◽  
Vol 68 (4) ◽  
pp. 719-725 ◽  
Author(s):  
P. A. Hayes ◽  
T. A. Steeves ◽  
B. R. Neal
Keyword(s):  
Key Words ◽  
Growth Patterns ◽  
Seedling Stage ◽  
Architectural Analysis ◽  
Lateral Buds ◽  
Branching Patterns ◽  
Architectural Models ◽  
Morphology Development ◽  
Shepherdia Canadensis ◽  
Root Buds

The growth patterns of Shepherdia canadensis and S. argentea from seedling stage to adult thicket have been analyzed and compared. In S. canadensis, the seedling axis, originally erect, showed a tendency for early bending towards the horizontal, followed by vertical reorientation of the tip. This was coupled with the basitonic expansion of lateral buds. In contrast, the seedling axis of S. argentea remained erect and branching was predominately acrotonic. As plants of S. canadensis matured, successive branches repeated the seedling pattern, reorienting downward with the tip compensating to remain erect. Basal buds expanded to fill the gap in the canopy and these in turn reoriented downward, repeating the cycle and forming a thicket with the youngest shoots in the centre. Rooting of the horizontal axes was observed and in some cases new thickets could be inititated in this way. In S. argentea, however, shoots remained erect and thicket formation occurred by the expansion of ramets from root buds at the periphery of the thicket. The shoots at the centre were thus the oldest. These features, together with information on branching patterns previously reported, have been used to construct constrasting architectural models for the two species. Key words: Elaeagnaceae, Shepherdia, Buffaloberry, architecture, morphology, development.

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.

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.

Shoot development in Betula papyrifera. V. Effect of male inflorescence formation and flowering on long shoot development

1984 ◽  
Vol 62 (8) ◽  
pp. 1708-1713 ◽  
Author(s):  
J. Cartey Caesar ◽  
Alastair D. Macdonald
Keyword(s):  
Dry Weight ◽  
Shoot Development ◽  
Growth Potential ◽  
Bud Burst ◽  
Betula Papyrifera ◽  
Short Shoot ◽  
Shoot Buds ◽  
Long Shoots ◽  
One Year ◽  
Old Trees

One-year-old vegetative and reproductive long shoots of Betula papyrifera Marsh, were collected from 40-year-old trees when leaves were fully expanded. Leaf areas were significantly reduced on shoots bearing developing male inflorescences; late leaves were affected most. Late leaves were thinner than early leaves on vegetative shoots and thinnest on reproductive shoots. The effect of developing male inflorescences was most pronounced on the specific leaf area of early leaves, suggesting that inflorescences are strong sinks for assimilates being exported by early leaves. Two-year-old vegetative and reproductive branches were collected just after bud burst to determine mean bud dry weight. These values were highest for buds on vegetative long shoots, lower for buds on reproductive long shoots, and lowest for buds on reproductive long shoots bearing female short-shoot buds. Formation of male inflorescences reduced the growth potential of buds. Female short-shoot buds on reproductive long shoots and pseudoterminal buds positioned below male inflorescences exhibited reduced growth potentials. Mean total early leaf areas measured 3 weeks after flushing showed similar trends. Thus, development and flowering of male inflorescences lowered the growth potential and vigour of axillary buds and reduced canopy expansion.

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.

The population dynamics of metacercariae of Apatemon gracilis (Trematoda: Digenea) in three species of lake-dwelling leeches

Parasitology ◽  
1986 ◽  
Vol 93 (3) ◽  
pp. 517-530 ◽  
Author(s):  
S. M. Spelling ◽  
J. O. Young
Keyword(s):  
Population Dynamics ◽  
Relative Density ◽  
Sexual Maturity ◽  
Egg Production ◽  
Seasonal Pattern ◽  
Distinct Pattern ◽  
The Other ◽  
Mean Intensity ◽  
Density Values ◽  
Host Mortality

SUMMARYMonthly samples of the leeches Erpobdella octoculata, Glossiphonia complanata and Helobdella stagnalis were taken over a two-year period from an eutrophic, English lake to detect metacercariae of the trematode, Apatemon gracilis. In each cohort of each of the three leeches, prevalence was low in young individuals, rose to a peak in autumn/winter, and then declined until the cohort had almost died out; in E. octoculata and H. stagnalis a final brief increase occurred. Mean intensity and relative density values followed a similar seasonal pattern of change to that of prevalence in these last two species, but in G. complanata values fluctuated irregularly with no distinct pattern. The frequency distribution of the parasite in G. complanata was highly over-dispersed, but less so in the other two species. Infected E. octoculata reached sexual maturity. The parasite reduced egg production in G. complanata and H. stagnalis, but only by maximum values of 2·5 and 9% respectively. This reduction in fecundity is low compared to the subsequent high mortality, at 95% or more, of newly recruited young from as yet unidentified causes. Parasite-related host mortality was difficult to assess in young leeches, but there was some evidence for its occurrence in older leeches of E. octoculata and H. stagnalis. However, this is unlikely to play a prominent role in the control and regulation of lacustrine leech populations.

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