Initiation and development of leaves in Douglas fir

1968 ◽  
Vol 46 (3) ◽  
pp. 271-278 ◽  
Author(s):  
John N. Owens
Keyword(s):  
Cell Division ◽  
Shoot Apex ◽  
Growing Season ◽  
Douglas Fir ◽  
Intercalary Cell ◽  
Short Time ◽  
Peripheral Cells ◽  
Marginal Meristem ◽  
Growth Periodicity ◽  
Fall Growth

The initiation and development of the leaves of Douglas fir is described in detail. Leaf initiation is similar to that of other foliar organs and involves both protodermal and peripheral cells of the apex. Apical and subapical initials are present but active for only a short time. Most enlargement is a result of intercalary cell division and enlargement. A limited marginal meristem is present. No differentiation of tissues occurs before bud dormancy in the fall. Growth following dormancy shows the various tissues to mature at different rates and all tissues are fully mature when the leaf becomes dormant in the fall. Growth periodicity of the shoot apex and the length of the growing season are discussed. Initiation and development of leaves in relation to all other foliar organs in Douglas fir are compared.

Electronmicroscopic localization of ribonucleic acids in ciliate Bursaria truncatella during cell division

1990 ◽  
Vol 48 (3) ◽  
pp. 132-133
Author(s):  
Vladimir Popenko ◽  
Natalya Cherny ◽  
Maria Yakovleva
Keyword(s):  
Cell Division ◽  
High Specificity ◽  
Longitudinal Axis ◽  
Gold Complexes ◽  
Somatic Nucleus ◽  
Ribonucleic Acids ◽  
Biological Meaning ◽  
Bivalent Cations ◽  
Lowicryl K4m ◽  
Short Time

Highly polyploid somatic nucleus (macronucleus) of ciliate Bursaria truncatella under goes severe changes in morphology during cell division. At first, macronucleus (Ma) condences, diminishes in size and turns perpendicular to longitudinal axis of the cell. After short time, Ma turns again, elongates and only afterwards the process of division itself occurs. The biological meaning of these phenomena is not clear.Localization of RNA in the cells was performed on sections of ciliates B. truncatella, embedded in “Lowicryl K4M” at various stages: (1) before cell division (Figs. 2,3); (11) at the stage of macronucleus condensation; (111) during elongation of Ma (Fig.4); (1111) in young cells (0-5min. after division). For cytochemical labelling we used RNaseAcolloidal gold complexes (RNase-Au), which are known to bind to RNA containing cell ularstructures with high specificity. The influence of different parameters on the reliability and reproducibility of labelling was studied. In addition to the factors, discussed elsewhere, we found that the balance of mono- and bivalent cations is of great significance.

Morphogenesis in hydra

Development ◽  
1970 ◽  
Vol 24 (1) ◽  
pp. 21-32
Author(s):  
Sondra C. Corff ◽  
Allison L. Burnett
Keyword(s):  
Nervous System ◽  
Cell Division ◽  
Hydrostatic Pressure ◽  
Low Temperature ◽  
Low Temperatures ◽  
Mitotic Division ◽  
Basal Disc ◽  
Dividing Cells ◽  
Short Time ◽  
Disc Formation

When Hydra oligactis is excised below the tentacles and incubated for a short time in concentrations of colchicine that inhibit spindle formation in dividing cells, a peduncle and basal disc subsequently form at the cut distal end, where hypostome and tentacles normally form (Corff & Burnett, 1969). Since recent reports suggest a similarity in the action of colchicine and low temperature, in this study the effects of low temperatures on regenerating hydra were investigated. High hydrostatic pressure and low temperature have been shown to act synergistically with colchicine to inhibit the first mitotic division in sea urchin eggs (Marsland, 1968). Colchicine and cooling have also been shown to cause disintegration of the microtubule system in Actinosphaerium (Tilney, 1965). We have previously discussed peduncle and basal disc formation at the distal end in terms of colchicine inhibition of cell division and the possible action of colchicine on the nervous system (Corff & Burnett, 1969).

Some observations on the shoot growth of pine seedlings

1976 ◽  
Vol 6 (3) ◽  
pp. 341-347 ◽  
Author(s):  
S. Thompson
Keyword(s):  
Scots Pine ◽  
Shoot Apex ◽  
Shoot Growth ◽  
Lodgepole Pine ◽  
Growing Season ◽  
Pine Seedlings ◽  
Terminal Bud

Sequential observations in lodgepole pine (Pinuscontorta Dougl.) and Scots pine (P. sylvestris L.) showed that the second season's shoot was not produced solely from stem units in the terminal resting bud as previously assumed. The stem units held in the rosette of primary needles surrounding the terminal bud elongated to form most of the second season's shoot. The terminal bud only contributed 29 to 54% of the stem units. There was a marked difference between an inland and a coastal provenance of lodgepole pine in the appearance of the shoot apex at the end of the first growing season.

Ectomycorrhizae and growth of Douglas-fir seedlings preinoculated with Rhizopogonvinicolor and outplanted on eastern Vancouver Island

1993 ◽  
Vol 23 (8) ◽  
pp. 1711-1715 ◽  
Author(s):  
S.M. Berch ◽  
A.L. Roth
Keyword(s):  
Cold Storage ◽  
Growing Season ◽  
Vancouver Island ◽  
Douglas Fir ◽  
The Other ◽  
Field Soil ◽  
Field Season ◽  
Ectomycorrhizal Colonization ◽  
Growth Differences ◽  
And Control

Ectomycorrhizal colonization of container-grown Pseudotsugamenziesii (Mirb.) Franco (Douglas-fir) inoculated with Rhizopogonvinicolor A.H. Smith was determined after cold storage and after one growing season on a clearcut on eastern Vancouver Island. Inoculated Douglas-fir seedlings were taller than noninoculated controls when outplanted but, perhaps because of browse damage, no growth differences were found after one field season. Rhizopogonvinicolor colonized all of the inoculated but none of the control seedlings examined after cold storage. Volunteer Thelephoraterrestris Fr. colonized almost half of the control and 10% of the inoculated seedlings before outplanting. After one field season, inoculated and control seedlings were colonized by 15 ectomycorrhizal fungi each, only eight of which were found on both. Rhizopogonvinicolor persisted on the roots of inoculated plants, but was also present in the field soil since the control seedlings also bore these mycorrhizae after one growing season. The relative abundance of T. terrestris decreased from the nursery to the field. The other common ectomycorrhizae in the field included Myceliumradicisatrovirens Melin, Cenococcumgeophilum Fr., and types resembling Tuber and Endogone.

Carbon and nitrogen allocation patterns of Douglas-fir seedlings fertilized with nitrogen in autumn. II. Field performance

1986 ◽  
Vol 16 (5) ◽  
pp. 903-909 ◽  
Author(s):  
H. A. Margolis ◽  
R. H. Waring
Keyword(s):  
Free Amino ◽  
Shoot Growth ◽  
Field Performance ◽  
Growing Season ◽  
Frost Damage ◽  
Douglas Fir ◽  
Summer Drought ◽  
Tree Roots ◽  
Relative Growth ◽  
Relative Growth Rates

October-fertilized and unfertilized 2-0 Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings were outplanted the following February. Half of each planting block was seeded with grass to induce water stress during the typical summer drought. Sucrose was applied to soil around each seedling to limit availability of nitrogen to tree roots. Fertilized seedlings broke bud 9–10 days earlier, produced more shoot growth, and, as shown in later harvests, had higher relative growth rates than unfertilized seedlings. However, initial differences in growth response were due primarily to the earlier budbreak. Seedlings growing with grass had predawn water potentials of −1.5 MPa by early August; by September 3, unfertilized seedlings growing with grass were significantly more stressed than any others. Although free amino acid and total nitrogen concentrations were higher in fertilized than unfertilized seedlings when planted, they became equal by the end of one growing season. However, fertilized seedlings contained more free amino acids and nitrogen because of their greater size. Grass competition affected both seedling nitrogen and carbohydrate chemistry. After one growing season, fertilized seedlings had greater height increment, shoot growth, leaf area, relative growth rate, and production per unit nitrogen. Although autumn fertilization benefited these Douglas-fir seedlings, negative effects could result from carbohydrate depletion because of increased respiration or from frost damage because of earlier budbreak.

Bulldozing stumps and nitrogen fertilization affect growth of Douglas-fir seedlings

1988 ◽  
Vol 18 (6) ◽  
pp. 803-806 ◽  
Author(s):  
W. G. Thies ◽  
E. E. Nelson
Keyword(s):  
Ammonium Nitrate ◽  
Nitrogen Fertilization ◽  
Growing Season ◽  
Douglas Fir ◽  
Olympic Peninsula ◽  
Diameter At Breast Height ◽  
Clear Cut ◽  
Breast Height ◽  
Growing Seasons ◽  
Growth Of Seedlings

Eight treatments involving stump removal by bulldozing in combination with nitrogen fertilization were applied to 0.04-ha circular plots in a clear-cut on the Olympic Peninsula, Washington. Treatments included stump removal (either all stumps removed or the plot left undisturbed) and broadcast fertilization with ammonium nitrate (0, 336, 672, or 1345 kg N ha−1). Diameter at breast height and height of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings, planted several months after treatment, were recorded five and eight seasons after outplanting. The results showed that either bulldozing stumps from the site or fertilizing with ammonium nitrate increased growth of seedlings through their eighth growing season. After eight growing seasons, bulldozing had increased seedling height by 23% and diameter at breast height by 43%; fertilizing produced increases of 13% in height and 17% in diameter at breast height.

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