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.

Crown architecture of Larix laricina saplings: quantitative analysis and modelling of (nonsylleptic) order 1 branching in relation to development of the main stem

1984 ◽  
Vol 62 (9) ◽  
pp. 1904-1915 ◽  
Author(s):  
W. R. Remphrey ◽  
G. R. Powell
Keyword(s):  
Morphological Variability ◽  
Natural Populations ◽  
Height Growth ◽  
Main Stem ◽  
Larix Laricina ◽  
Crown Architecture ◽  
Growth Increments ◽  
Long Shoots ◽  
Architectural Models ◽  
Short Shoots

The upper 5 years of crown growth in samples of Larix laricina (Du Roi) K. Koch (tamarack) saplings from natural populations in the Fredericton, N.B., area provided data to model architectural relationships describing patterns of (nonsylleptic) order 1 branching in relation to development of the main stem. The model was based on relationships between branch extension and height growth, and numbers and positions of order 1 branches. Elevation angles of shoots making up the branches, and conversion of order 1 long shoots to order 1 short shoots were also incorporated. Lengths of current shoots of major order 1 branches tended to decrease with increasing depth in the crown. Similar tendencies occurred among lengths of all current branch extensions within single height-growth increments, but the decreases in length became less regular with increasing age of branch. Because the relationships were complex, alternative approaches to modelling shoot lengths were adopted to enhance understanding of the patterns involved. Deterministic and stochastic elements were used in the overall model to account for significant proportions of morphological variability. Simulations based on the alternatives within the model were realistic in their interpretations of actual sapling crown architecture. Classification of L. laricina according to previously proposed architectural models that qualitatively describe general development was discussed.

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.

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.

Shoot type demography and dry matter partitioning: a morphometric approach in apple (Malus ×domestica)

2001 ◽  
Vol 79 (11) ◽  
pp. 1270-1273 ◽  
Author(s):  
Pierre-Éric Lauri ◽  
Jean-Jacques Kelner
Keyword(s):  
Leaf Area ◽  
Malus Domestica ◽  
Detrimental Effect ◽  
Canopy Structure ◽  
Short Shoot ◽  
Dry Matter Partitioning ◽  
Fruiting Branch ◽  
Long Shoots ◽  
Short Shoots ◽  
Time Required

In a study of the apple (Malus ×domestica Borkh.) canopy structure, 5-year-old 'Fuji' and 'Braeburn' trees grafted on a low-vigour rootstock (M9) were compared at both fruiting branch and shoot levels. Percentages of short ([Formula: see text]5 cm) shoots and short shoot leaf area were significantly higher on 'Braeburn' than on 'Fuji', (76.8% vs. 72.6% and 46.9% vs. 42.9% for 'Braeburn' and 'Fuji', respectively). This high percentage of short shoots as compared with literature data was probably due to the training method, which reduced vigour. At shoot level, the ratio between dry masses of axis and leaf, called the axialization index, was determined to compare short and long shoots. Axialization values were higher for 'Braeburn' than for 'Fuji'. Although overall and individual leaf area was greater on long shoots, long shoot axialization (0.64 and 0.54 for 'Braeburn' and 'Fuji', respectively) was approximately twice that of short shoots (0.36 and 0.24, respectively). Therefore, for short shoots, the reduced carbon investment in supporting tissues may explain the significant role short shoots played in supporting early fruit development. For long shoots, the longer time required to reach the autotrophic and then exporting stage as well as the detrimental effect of early extension shoot development on fruit set might be explained by greater axialization.Key words: long shoot, short shoot, axialization index, apple, Malus ×domestica, biomass partitioning.

Branch architecture of sagebrush and bitterbrush: use of a branch complex to describe and compare patterns of growth

1991 ◽  
Vol 69 (6) ◽  
pp. 1288-1295 ◽  
Author(s):  
C. J. Bilbrough ◽  
J. H. Richards
Keyword(s):  
Growth Form ◽  
Artemisia Tridentata ◽  
Growth Patterns ◽  
Developmental Morphology ◽  
Branch Architecture ◽  
Purshia Tridentata ◽  
Shoot Production ◽  
Long Shoots ◽  
Repeated Structure ◽  
Short Shoots

The concept of the modularity of plant growth form was incorporated with the fates of buds and used as a framework to describe the typical branch-level developmental morphology of sagebrush (Artemisia tridentata ssp. vaseyana (Rydb.) Beetle) and bitterbrush (Purshia tridentata (Pursh) D.C.). Typical branches included one 2-year-old long shoot and all 1-year-old long shoots originating from that twig. Growth patterns were examined by position along each long shoot within the experimental branches. Shoot fates were recorded for each node and biomass production was estimated. Both species had specific locations where vegetative long shoot production was higher than any other location within the experimental branches. Sagebrush had an overall linear (excurrent) growth form, with the leader long shoot much larger than lateral long shoots. Sagebrush produced many lateral long shoots and few short shoots. In contrast, bitterbrush had a branched (decurrent) growth form, with few long shoots and many short shoots. The leader rarely grew and was no larger than laterals. Knowledge of the location, frequency, and size of vegetative long shoot production within a branch complex provides an understanding of the repeated structure of plants. The branch-level approach provides the information necessary before the effects of environmental factors on growth patterns can be determined. Key words: Artemisia tridentata ssp. vaseyana (Rybd.) Beetle, branch architecture, bud fates, developmental morphology, Purshia tridentata (Pursh) D.C., shrub.

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.

scholarly journals Comparison of flower bud development in almond, apricot and peach genotypes

2006 ◽  
Vol 12 (2) ◽  
Author(s):  
L. Szalay
Keyword(s):  
Alternative Methods ◽  
Flower Bud ◽  
Continuous Space ◽  
Bud Development ◽  
Fruit Species ◽  
Long Shoots ◽  
Floral Primordia ◽  
Short Shoots ◽  
Pistil Development ◽  
Flower Bud Development

The phenological processes of flower bud development of stone fruits during dormancy are not thoroughly known. The yield of these species, especially of almond, apricot and peach is determined basically by dormancy of flower buds, the survival rate of buds during winter frosts and by their ability to develop normal floral organs in the next spring. After the initiation of floral primordia, flower bud development is taking place in continuous space until blooming, though at different speed characteristic to the species. To study flower bud development during dormancy we applied two alternative methods in different genotypes of almond, apricot and peach: (1) examination of pollen development (microsporogenesis), and (2) the measurement of pistil length. The samples were collected from the central part of Hungary during the dormancy period of 2004/2005. The three fruit species differed significantly in the speed of flower bud development, it was the quickest in almond, followed by apricot and peach. In addition to the species, there were significant differences in the process of microsporogenesis and pistil development between genotypes within species and also between the different types of shoots on which the buds were located. On short shoots buds developed at a higher speed, than on long shoots. Based on our observations, on the short shoots the period of endodormancy was shorter with 5-30 days, according to genotypes, compared to the long shoots. This difference, however, decreased to 2-3 days by the time of blooming.

scholarly journals In Vitro Responses of Tissues from Rhododendron Plants With and Without Tissue Proliferation

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 873D-873
Author(s):  
Yiqin Ruan ◽  
Mark H. Brand
Keyword(s):  
Growth Rates ◽  
Woody Plant ◽  
Shoot Tips ◽  
Shoot Cultures ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Tissue Proliferation ◽  
Long Shoots ◽  
Short Shoots

Rhododendron `Montego' shoot cultures initiated from plants with and without tissue proliferation (TP and NTP) served as explant sources for all studies (Note: in vitro TP shoot cultures produce primarily dwarf shoots, some long shoots, and stem tumors). Calli induced from TP leaves and tumors and NTP leaves were cultured on woody plant (WP) medium containing NAA and 2-iP. During the first 4 weeks of culture, calli from NTP leaves had higher relative growth rates than calli from TP leaves or tumors. However, calli from TP leaves and tumors grew faster than calli from NTP leaves for all subculture periods that followed. Shoot tips (5 mm) were excised from TP dwarf shoots, TP long shoots, and NTP shoots and were cultured on WP medium with or without 15 μM 2-iP. Shoot tips from TP dwarf and long shoots multiplied on medium without 2-iP, averaging 18.4 and 1.7 shoots per shoot tip in 12 weeks, respectively. Shoot tips from NTP shoots only multiplied when maintained on 2-iP-containing medium. When placed on 2-iP-containing medium, both types of TP shoot tips produced clusters of callus-like nodules that gave rise to highly tumorized, short shoots or leafy meristems.

Sign in / Sign up

Export Citation Format

Share Document