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.

Shoot development in Betula papyrifera. I. Short-shoot organogenesis

1983 ◽  
Vol 61 (12) ◽  
pp. 3049-3065 ◽  
Author(s):  
Alastair D. Macdonald ◽  
D. H. Mothersill
Keyword(s):  
Axillary Buds ◽  
Axillary Bud ◽  
Bud Burst ◽  
Betula Papyrifera ◽  
Short Shoot ◽  
Mature Trees ◽  
Shoot Buds ◽  
Female Inflorescence ◽  
Terminal Bud ◽  
Short Shoots

Buds and developing branches of Betula papyrifera were collected weekly from mature trees during three successive growing seasons. Material was prepared to show stages of bud inception, development, and flushing and female inflorescence inception. Short shoots develop from (i) proximal axillary buds on long shoots (ii) short-shoot terminal buds, or (iii) axillary buds on flowering short shoots. An axillary bud apex forms a terminal bud after bud burst. An axillary bud possesses one outer rudimentary leaf, but all other short-shoot buds have three outer rudimentary leaves. All short-shoot buds possess, in addition, one–three embryonic foliage leaves and, distally, three primordial rudimentary leaves which form the outermost appendages of the succeeding terminal bud. Rudimentary leaf stipules form the cataphylls. Foliage leaf primordia are initiated in May – early June and rudimentary leaves arise in late June – July. If a bud apex is initiated in year n, female inflorescence induction occurs in late June of year n + 1 or any succeeding year. An axillary bud develops on a short shoot as a consequence of flowering; it is initiated concurrently with inflorescence development and its development is completed during flowering and seed maturation. Short- and long-shoot buds can be distinguished, upon dissection, in mid-July when buds are forming. Hence, determination of potential long and short shoots occurs the year before bud burst.

Shoot development in Betula papyrifera. VI. Development of the reproductive structures

1987 ◽  
Vol 65 (3) ◽  
pp. 466-475 ◽  
Author(s):  
Alastair D. Macdonald ◽  
D. H. Mothersill
Keyword(s):  
Male Flower ◽  
Female Flower ◽  
Bud Burst ◽  
Betula Papyrifera ◽  
Short Shoot ◽  
Mature Trees ◽  
Male And Female ◽  
Shoot Bud ◽  
Growing Seasons ◽  
Northwestern Ontario

Reproductive buds and developing inflorescences were collected weekly from mature trees during three successive growing seasons in northwestern Ontario. Material was prepared to show all stages of inflorescence and flower development and meiosis. Male inflorescence induction, involving the long-shoot bud apex and one or two proximal axillary apices, occurred in early May, before bud burst. Female induction involved the short-shoot bud apex and occurred in late June – early July. Both male and female partial inflorescences resembled a simple dichasium. The male flower consisted of usually two stamens and two or three tepals variably arranged. Meiosis occurred in late July – early August. Each female flower consisted of two stigmas, two connate tepals that were not noticeable at maturity, and a parietal placenta bearing two unitegmic ovules. Meiosis occurred in mid-June, after pollination in mid-May. It is concluded that developmental data do not help elucidate whether the inferior portion of the gynoecial wall is cauline or appendicular and whether the placenta is derived from axial or carpellary tissue. It is suggested that the trigger(s) evoking male and female inflorescence induction may be different and that the metabolic prerequisites for induction and early development would be supplied by winter-stored material for male development and by current metabolic processes for female development.

Shoot development in Betula papyrifera. IV. Comparisons between growth characteristics and expression of vegetative long and short shoots

1984 ◽  
Vol 62 (3) ◽  
pp. 446-453 ◽  
Author(s):  
J. Cartey Caesar ◽  
Alastair D. Macdonald
Keyword(s):  
Growth Rates ◽  
Stem Elongation ◽  
Morphological Characteristics ◽  
Axillary Buds ◽  
Betula Papyrifera ◽  
Short Shoot ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Long Shoots ◽  
Short Shoots

Postflush observations on shoots of Betula papyrifera Marsh. indicated that long and short shoots differ in a range of morphological characteristics. Long shoots developed from distal axillary buds and short shoots developed from proximal axillary buds on the previous year's long shoots. Consequently, the potential of a bud to develop into a long shoot decreased basipetally. Potential long-shoot buds had higher bud-relative growth rates, stem-relative growth rates, leaf-relative growth rates, and stem dry weights during the course of postflush growth. Changes in leaf thickness, expressed in terms of specific leaf area and specific leaf weight, indicated that long shoots temporarily had thinner leaves than did short shoots a few weeks after flushing. Net assimilate requirements in long shoots for late leaf and internodal expansion may explain these observations. Nearing maturity, long-shoot early leaves became thicker, possibly owing to greater shoot vigour and (or) higher photosynthetic efficiency. Consequently, mature long-shoot early leaves possessed larger and thicker laminae, longer petioles, more side nerve pairs, and tended to grow more in length than width than short-shoot leaves on shoots of comparable age. Leaves of older short shoots, 2–10 years old, attained a greater size and had longer petioles than those of 1-year-old short shoots. Stem elongation and the development and expression of leaves in long shoots seemed to have a correlative influence on the overall vigour of long shoots.

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.

Promalin promotes lateral shoot development of young cherry trees

1981 ◽  
Vol 21 (113) ◽  
pp. 618 ◽  
Author(s):  
N Veinbrants ◽  
P Miller
Keyword(s):  
Shoot Growth ◽  
Shoot Development ◽  
Bud Burst ◽  
Lateral Shoot ◽  
Commercial Formulation ◽  
Total Length ◽  
Lateral Shoots ◽  
One Year ◽  
Cherry Trees

Promalin (a commercial formulation of N-(phenylmethy1)-1 H-purin-6-amine plus gibberellins A4 + A7) applied at bud swell and bud burst increased the number of spurs and lateral shoots on one-year-old wood of primary scaffold limbs of young cherry trees. Painted applications gave more consistent responses than sprayed applications. Total length of shoot growth on treated three-yearold cherry trees was more than double that of control trees and lateral shoots induced by Promalin had broad crotch angles.

scholarly journals Genotypic Differences in the Length-Diameter Relationship of Branches of One-year-old Peach and Nectarine Trees

1994 ◽  
Vol 119 (3) ◽  
pp. 616-619 ◽  
Author(s):  
Jocelyne Kervella ◽  
Loïc Pagès ◽  
Michel Génard
Keyword(s):  
Prunus Persica ◽  
Genotypic Differences ◽  
Breeding Programs ◽  
Basal Diameter ◽  
Long Shoots ◽  
Short Shoots ◽  
Thickness Variations ◽  
One Year ◽  
Old Trees ◽  
Relationship Of

Genotypic variations in the length-diameter relationship of branches among peach and nectarine [Prunus persica (L.) Batsch.] cultivars were investigated. The length and basal diameter of all undamaged first-order shoots from 1-year-old trees of 14 cultivars and one accession were measured. Statistical analysis of the allometric relationship between length and basal diameter of shoots provided evidence of genotypic differences for that relationship, although the diameter of very short shoots did not differ between genotypes. A gradient existed from `Armking' with thin shoots (9 mm in diameter for 85.5-cm-long shoots) to `Flavorcrest' with thick shoots (16.4 mm in diameter for 85.5-cm-long shoots). Early selection for shoot thickness should be possible in breeding programs. The likely consequences of observed shoot thickness variations on the mechanical and hydraulic properties of shoots are discussed.

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.

Shoot development in Betula papyrifera. II. Comparison of vegetative and reproductive short-shoot growth

1983 ◽  
Vol 61 (12) ◽  
pp. 3066-3071 ◽  
Author(s):  
J. Cartey Caesar ◽  
Alastair D. Macdonald
Keyword(s):  
Leaf Area ◽  
Shoot Growth ◽  
Inhibitory Influence ◽  
Betula Papyrifera ◽  
Short Shoot ◽  
Relative Growth ◽  
Shoot Buds ◽  
Mean Relative Growth Rate ◽  
Short Shoots ◽  
Terminal Buds

Short shoots of Betula papyrifera Marsh, may be vegetative or reproductive. The latter bear a female inflorescence. Early flushing and rapid growth of short-shoot buds depend on the age and position of the short shoot. Axillary short-shoot buds flush later than 2- to 4-year-old short-shoot terminal buds, which in turn flush later than 5- to 10-year-old shoots. Mean relative growth rate (RGR) of 5- to 10-year-old short-shoot buds is greater than that of younger short-shoot buds. It is suggested that older short-shoot buds are relatively autonomous and that the flushing long shoot exhibits an inhibitory influence on the proximal axillary buds and possibly on young short-shoot terminal buds. Reproductive short shoots differ from vegetative short shoots in that they have lower leaf area ratios and leaf RGR, higher specific leaf area, smaller leaf areas, and fewer side nerve pairs and they grow more in length than in width. These findings are related to reproductive cost. The developing inflorescences act as preferred "sinks" for resource allocation.

Occurrence and distribution of cones borne laterally on long shoots of Larix laricina

1984 ◽  
Vol 62 (4) ◽  
pp. 771-777 ◽  
Author(s):  
G. R. Powell ◽  
Kathleen J. Tosh ◽  
W. R. Remphrey
Keyword(s):  
Larix Laricina ◽  
Short Shoot ◽  
Shoot Buds ◽  
First Order ◽  
Long Shoots ◽  
Short Shoots

Trees of Larix laricina (Du Roi) K. Koch reaching the stage of first cone bearing tended to produce the majority of their seed cones, and many of their pollen cones, in lateral (axillary) positions along long shoots. In subsequent cone bearing, a greater proportion of the cones occurred in the typical (for the genus) position terminating short shoots. Some trees 2 to 4 m tall bore over 500 lateral seed cones. Lateral cones occurred on all kinds of long shoots, except sylleptic first-order shoots, produced in the 3-year-old portion of the crown. Lateral seed cones were borne on the morphogenically proximal halves of the long shoots and on all surfaces around the circumference of the shoots, but they were less frequent on upper surfaces than on other surfaces. Lateral pollen cones occurred in the proximal 10% of the lengths of the bearing shoots and were restricted to the undersurfaces or sides of the shoots. Lateral cone buds were distinctively larger and contained more bud scales than adjacent lateral short-shoot buds.

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.

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