Shoot morphology and fate of buds in relation to crown location in young Fraxinus pennsylvanica var. subintegerrima

2002 ◽  
Vol 80 (12) ◽  
pp. 1274-1282 ◽  
Author(s):  
William R Remphrey ◽  
Grant A Bartlett ◽  
Campbell G Davidson
Keyword(s):  
Simulation Model ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Shoot Morphology ◽  
Shoot Bud ◽  
Lateral Shoots ◽  
Shoot Size ◽  
Shoot Position ◽  
Morphological Patterns

The relationships between shoot size and morphological patterns and crown location were investigated in 6-year-old green ash (Fraxinus pennsylvanica var. subintegerrima (Vahl) Fern.). In general, shoots were shorter in the inner part of the crown compared with either the top or bottom near the periphery. The differences were related to a reduction in both metamer number and length. In some cases the lower crown location was similar to the upper; in other cases it was similar to the inside. The fate of buds along a shoot was generally dependent on shoot position in the crown. A greater proportion of buds became lateral shoots and inflorescences in the top compared with the bottom of the crown, and the fewest developed towards the inside location. As the number of metamers per shoot increased, there was an increase in the proportion of lateral shoots produced and a decrease in the proportion of inflorescences and (or) aborted buds. For shoots with the same number of metamers per shoot, those in the top produced a greater proportion of inflorescences and lateral shoots compared with the bottom or inside. In all crown locations, the highest number of buds aborted near the base, the greatest proportion of inflorescences occurred in mid-shoot regions, and the largest proportion of lateral shoots occurred near the tip. The information presented in this paper will be used as a component in developing a simulation model of crown development.Key words: architecture, shoot, bud fate, green ash, metamer.

An analysis of architectural parameters of male and female Fraxinus pennsylvanica in relation to crown shape and crown location

1990 ◽  
Vol 68 (9) ◽  
pp. 2035-2043 ◽  
Author(s):  
Campbell G. Davidson ◽  
William R. Remphrey
Keyword(s):  
Principal Component ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Male And Female ◽  
Lateral Shoots ◽  
Crown Shape ◽  
Sampling Height ◽  
Shape Class ◽  
Key Variables ◽  
Oval Shape

Architectural variables from male and female green ash (Fraxinus pennsylvanica var. subintergerrima (Vahl) Fern.) comprising three different crown-shape classes were analyzed at four different crown levels to determine which variables influenced crown shape. The narrow conical shape class had the largest mid shoot diameters and the smallest shoot tip abortion frequencies. The broad to round shape class had greater abortion frequency overall. In addition, there was less difference in shoot length between the top and bottom of the crown. The more oval shape class was intermediate for both shoot diameters and abortion frequency. Parent and daughter shoot lengths were longer, midshoot diameters larger, and elevation angles greater with increasing sampling height in the tree. Male trees had shorter shoot lengths and shorter and fewer daughter lateral shoots than female trees. Principal component analysis was used to identify shoot lengths, elevation angles, and abortion frequencies as potentially key variables in understanding crown shape in green ash. Interrelationships of many of the architectural variables suggest that a significant change in one may lead to changes in others, which ultimately would lead to changes in overall crown shape.

scholarly journals The effect of nitrogen on growth and architecture of Fraxinus pennsylvanica 'Patmore' (green ash) in Field-grow containers at two sites in Manitoba, Canada

1996 ◽  
Vol 76 (4) ◽  
pp. 825-833 ◽  
Author(s):  
W. R. Remphrey ◽  
C. G. Davidson
Keyword(s):  
Growth And Development ◽  
Growth Increment ◽  
Height Growth ◽  
Shoot Length ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Growing Seasons ◽  
Lateral Shoots ◽  
N Treatment ◽  
Four Levels

Fraxinus pennsylvanica var. subintegerrima (Vahl) Fern. 'Patmore' green ash was established at two sites in southern Manitoba. Four levels of N fertilizer (4.5–400 ppm) were applied during two growing seasons. Growth and development of the trees was dependent on the site and local environmental conditions. At Morden, the annual height growth increment was greater with lower levels of N applications and declined at higher levels, while at Winnipeg higher levels resulted in greater growth. Stem diameter changes followed a similar pattern. The numbers of lateral shoots per parent shoot were only weakly affected by N treatment and any differences appeared to be an indirect effect of parental shoot length. The Field-grow containers at the Winnipeg site were installed in crass-sod which penetrated the containers and appeared to result in competition for N resources. The Morden site was kept cultivated and thus there was no such competition. At Morden, it is possible that wicking from the surrounding soil may have moved excessive salts into the containers resulting in high conductivity values and toxicity. Key words: Field-grow, biomass, roots, architecture, fertilization, Fraxinus pennsylvanica

Branch architecture and its relation to shoot-tip abortion in mature Fraxinus pennsylvanica

1992 ◽  
Vol 70 (6) ◽  
pp. 1147-1153 ◽  
Author(s):  
W. R. Remphrey ◽  
C. G. Davidson
Keyword(s):  
Shoot Length ◽  
Shoot Tip ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Annual Increment ◽  
Tree Form ◽  
Apical Control ◽  
Lateral Shoots ◽  
Crown Shape ◽  
Shape Class

The architecture of branch complexes, 10 to 14 years old, from mature male and female green ash trees (Fraxinus pennsylvanica var. subintegerrima (Vahl) Fern.) of two crown shapes was analyzed. Shoot length (annual increment of extension growth) declined with increasing order of branching and 47% of the shoots were less than 30 mm. Although variable, shoot length also tended to decrease along an axis. There was a consistent positive correlation between lengths and numbers of daughter shoots and lengths of parent shoots, but for a given parent length the predicted values declined proportionately with increasing order. An index of apical control comparing the lengths of terminal shoots with the longest lateral shoots revealed weaker apical control with increasing branch order in the broad, rounded crown shape class compared with the narrow shape class. Elevation angles of terminal daughter shoots were highly correlated with that of the parent shoot. When a shoot tip aborted, the terminal was replaced, but a weakening of apical control resulted in the modification of branch development and the formation of forks in certain axes. There was a reduction in the angle of divergence of lateral shoots in response to shoot-tip abortion, the terminal replacements being the most acute. Key words: crown architecture, shoot-tip abortion, green ash, Fraxinus, tree form, branching pattern.

scholarly journals Desiccation Tolerance of Green Ash and Sugar Maple Fine Roots

2009 ◽  
Vol 27 (4) ◽  
pp. 229-233 ◽  
Author(s):  
Gary W. Watson
Keyword(s):  
Root Growth ◽  
Fine Roots ◽  
Acer Saccharum ◽  
Sugar Maple ◽  
Fine Root ◽  
Cell Damage ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Root Electrolyte Leakage ◽  
Bare Root

Abstract Exposed fine roots are subject to desiccation, which may affect their survival as well as new root growth following bare root transplanting. Fine roots of dormant 1-year-old green ash (Fraxinus pennsylvanica) and sugar maple (Acer saccharum) seedlings, subjected to desiccation treatments of 0, 1, 2, or 3 hours in December and March, lost up to 82 percent of their water. Root electrolyte leakage, a measure of cell damage, tripled after three hours of desiccation. The increase was moderately, but significantly, greater in March for both species. Desiccation treatments had no effect on fine root survival. Growth of new roots (RGP) was also unaffected by desiccation treatments. RGP of maple was greater in March than December, but not ash.

Tolerance of Planed Hardwoods to Spring Flooding

1977 ◽  
Vol 1 (3) ◽  
pp. 23-25 ◽  
Author(s):  
James B. Baker
Keyword(s):  
Populus Deltoides ◽  
Growing Season ◽  
Liquidambar Styraciflua ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Nyssa Aquatica ◽  
Eastern Cottonwood ◽  
Platanus Occidentalis ◽  
Water Tupelo ◽  
Root Collar

Abstract Cuttings of eastern cottonwood (Populus deltoides) and seedlings of sweetgum (Liquidambar styraciflua), water tupelo (Nyssa aquatica), American sycamore (Platanus occidentalis), and green ash (Fraxinus pennsylvanica) were planted on a slackwater clay (Vertic Haplaquept) in western Mississippi in two consecutive years and inundated soon after foliation. During each of the two years, survival following flooding was consistently high for water tupelo, green ash, and sycamore, low for cottonwood, and intermediate for sweetgum. With the exception of green ash, however, all species lost their leaves and died back to the root collar during flooding. Thus trees, other than ash, that were living at the end of the growing season had originated from root collar sprouts.

Sex Differences in Green Ash

1979 ◽  
Vol 3 (4) ◽  
pp. 173-174
Author(s):  
John T. Talbert ◽  
Robert D. Heeren
Keyword(s):  
Sex Differences ◽  
First Generation ◽  
Tree Improvement ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Improvement Program ◽  
Male And Female ◽  
Sufficient Variation ◽  
Natural Stands ◽  
Male Superiority

Abstract A disproportionately large number of first-generation selections from natural stands of green ash (Fraxinus pennsylvanica Marsh.) have been male. A study was undertaken to determine if male and female green ash differed in several important economic characteristics. Only straightness differences could be shown to be statistically significant, and, even for this trait, several opinions were needed to detect male superiority. Sufficient variation should exist in natural stands to allow inclusion of superior individuals of both sexes in a tree-improvement program.

Heteroblastic seedlings of green ash. I. Predictability of leaf form and primordial length

1986 ◽  
Vol 64 (11) ◽  
pp. 2645-2649 ◽  
Author(s):  
E. K. Merrill
Keyword(s):  
Leaf Development ◽  
Leaf Growth ◽  
Leaf Primordia ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Leaf Form ◽  
Compound Leaf ◽  
Controlled Conditions ◽  
Plastochron Index

Green ash (Fraxinus pennsylvanica var. subintegerrima) seedlings are heteroblastic; during development they produce two types of leaves, simple and compound. When grown under controlled conditions, the sequence of leaf types is predictable. Simple leaves are always at the first four nodes; compound leaves are always at node 8 and above. Nodes 5 through 7 have progressively fewer simple leaves and more compound leaves. Leaf growth on seedlings meets the preconditions of the plastochron index and leaf plastochron index. These indices, as well as the length of single expanding leaves, can be used to predict lengths of leaf primordia at nodes 4 and 8 so that early, simple and compound leaf development can be compared in further studies of green ash.

Shoot ontogeny in Fraxinus pennsylvanica (green ash). II. Development of the inflorescence

1989 ◽  
Vol 67 (7) ◽  
pp. 1966-1978 ◽  
Author(s):  
W. R. Remphrey
Keyword(s):  
Fruit Set ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Dioecious Species ◽  
Male And Female ◽  
Floral Buds ◽  
Growing Seasons ◽  
Female Inflorescence ◽  
Mature Flower ◽  
Floral Apex

From initiation to fruit set, which occurs over three growing seasons, eight stages are recognized in the development of axillary inflorescences in the dioecious species Fraxinus pennsylvanica var. subintegerrima (Vahl) Fern, (green ash). In the first season, buds are initiated in the axils of foliage leaves. As the shoots expand in the following spring, the buds complete their development. Although similar at first, differences begin to emerge between vegetative and inflorescence buds in that the latter produce robust second-order meristems, the incipient paracladia, protruding close to the original apex. After about 3–4 weeks, when the initiation of such buds is complete, the terminal and subtending lateral meristems present on each axis develop into a three-membered cluster of floral buds. There was a mean of 214.3 ± 12.2 floral buds initiated per female inflorescence, and the number generally increased with the length of the associated shoot. A ridge, the incipient perianth, begins to form around the periphery of each rounded floral apex. Male and female floral buds are not distinguishable at this stage, but the inflorescence buds are distinctly different from vegetative buds. The male and female buds then diverge in their development in that an identation forms at the summit of the incipient gynoecium and male buds initiate two or three anthers. By autumn, the gynoecium is distinctly conical, with an orifice at its summit, and the anthers are lobed. There is lobing of the perianth ridge, but in the mature flower distinct organs traceable to such lobes could not readily be identified.

scholarly journals Variation in Aggressiveness of Ash Yellows Phytoplasmas

Plant Disease ◽  
2000 ◽  
Vol 84 (3) ◽  
pp. 282-288 ◽  
Author(s):  
W. A. Sinclair ◽  
H. M. Griffiths
Keyword(s):  
Fragment Length Polymorphism ◽  
Initial Strain ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Long Distance ◽  
Rapid Multiplication ◽  
Pcr Rflp ◽  
Polymerase Chain ◽  
Different Strains ◽  
Long Distance Movement

Twelve strains of phytoplasmas belonging to the ash yellows (AshY) group, from across the known range of AshY and representing six host species, were assessed for differences in ability to suppress growth and cause chlorosis in graft-inoculated Fraxinus pennsylvanica (green ash) and Catharanthus roseus (periwinkle). In each of two experiments with ash and one with periwinkle, different strains caused significantly different degrees of growth suppression and loss of foliar greenness. These growth and color impacts were positively and significantly correlated among experiments and between ash and periwinkle, indicating strain variation in aggressiveness. After two strains that differed in aggressiveness were coinoculated to periwinkle plants, polymerase chain reaction/restriction fragment length polymorphism (PCR/RFLP) assays of DNA from leaves remote from the inoculation sites revealed the presence of the aggressive strain sooner and more frequently than that of the less aggressive strain. Thus, aggressiveness was associated with more rapid multiplication and/or movement than was achieved by the less aggressive strain. When either strain was inoculated 11 weeks before the other into the same plant, only the initial strain could be detected after a further 12 weeks of incubation. Thus, the initial strain or its effect on the host may have interfered with multiplication and/or long-distance movement of the second strain. A concept of preemptive dominance is proposed to account for detection by primary PCR of only single phytoplasma strains in plants that may harbor two or more strains.

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