Effect of nursery culture on morphological development of western hemlock seedlings during field establishment. II. Survival, shoot length components, and needle length

1994 ◽  
Vol 24 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Conor O'Reilly ◽  
J.N. Owens ◽  
J.T. Arnott ◽  
B.G. Dunsworth
Keyword(s):  
Shoot Growth ◽  
Unit Length ◽  
Moisture Stress ◽  
Western Hemlock ◽  
Morphological Development ◽  
Needle Length ◽  
Nursery Culture ◽  
Reverse Pattern ◽  
Dormancy Induction ◽  
Short Days

Western hemlock (Tsugaheterophylla (Raf.) Sarg.) seedlings grown in two different container cavities that received four different dormancy induction treatments, short (SD) or long days (LD) in combination with moisture stress (D) or no stress (W) in the greenhouse, and lifted and placed in cold storage (November, January, or March), were planted on two adjacent coastal reforestation sites in British Columbia and monitored for survival and morphological development. Survival was greatest in seedlings grown in the larger cavities in the greenhouse, in seedlings lifted in March, and in seedlings not treated to moisture stress. Seedling shoots had more stem units on the southeast than the northwest site, but the amount varied with nursery treatment. Seedlings from the LD treatments produced more stem units during free growth and lammas growth than those from the SD treatment. Nevertheless, most shoot growth was predetermined in the buds during nursery culture, accounting for a minimum of 67% of the final number of stem units. Stem unit length (SUL) was longer in seedlings on the southeast site than on the northwest site for those treated to LD in the nursery. Seedlings treated to short days showed the reverse pattern (SDW) to this, or were unaffected by site (SDD). Shoots and needles were shortest for seedlings from the SDD treatment and for those lifted in November. Shoot growth was greatest for seedlings lifted in March and for those treated with LD, mainly owing to their longer SUL. Lammas growth was most frequent in seedlings from the smaller cavities, and in those from the November and March lifts.

Effect of nursery culture on morphological development of western hemlock seedlings during field establishment. I. Flushing, shoot elongation, and bud development

1994 ◽  
Vol 24 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Conor O'Reilly ◽  
J.N. Owens ◽  
J.T. Arnott ◽  
B.G. Dunsworth
Keyword(s):  
Cold Storage ◽  
Growing Season ◽  
Shoot Elongation ◽  
Moisture Stress ◽  
Western Hemlock ◽  
Morphological Development ◽  
Cavity Size ◽  
Bud Development ◽  
Nursery Culture ◽  
Dormancy Induction

Western hemlock (Tsugaheterophylla (Raf.) Sarg.) seedlings grown in two different container cavity sizes that received four different dormancy induction treatments, short (SD) or long days (LD), in combination with moisture stress (D) or no moisture stress (W), in the greenhouse, and lifted and placed in cold storage (November, January, or March) were planted on two adjacent coastal reforestation sites on Vancouver Island, British Columbia, and monitored for phenological responses during the first growing season. The SD seedlings flushed sooner and began bud development later than the LD seedlings, although the effect on flushing was small for those lifted in March. Moisture stress and SD together in the greenhouse reduced shoot elongation rates but had little impact on field bud development. Cold storage of seedlings lifted in November and January delayed flushing, reduced shoot elongation rates, and advanced bud development compared with the March-lifted stock. The influence of cavity size was generally small on most variables measured. Shoot elongation was slightly faster on the southeast site than on the northwest site, whereas bud development was more rapid on the northwest site. The effect of site on date of flushing varied with nursery treatment.

Early growth of planted spruce

1984 ◽  
Vol 14 (5) ◽  
pp. 644-651 ◽  
Author(s):  
A. N. Burdett ◽  
L. J. Herring ◽  
C. F. Thompson
Keyword(s):  
Root Growth ◽  
Shoot Growth ◽  
Slow Release ◽  
Unit Length ◽  
White Spruce ◽  
Early Growth ◽  
Height Growth ◽  
Needle Length ◽  
Growth Capacity ◽  
Root Growth Capacity

Observations were made on the growth of white spruce (Piceaglauca (Moench) Voss) and Engelmann spruce (P. engelmanni Parry), each planted at a single location in the interior of British Columbia. In both species bareroot stock (either 2 + 0 seedlings or 2 + 1 transplants) with a low root growth capacity made only limited height growth during the first two seasons after planting. In the first season, many short stem units were formed, whereas in the second season, stem units were much longer but many fewer. The length of needles formed after planting by the bareroot trees was, in the first season, only about half that of needles formed the previous year in the nursery. Needle length increased slightly in the 2nd year. Container-grown trees (1 + 0 seedlings from 336-mL containers), which had a high root growth capacity, made relatively good height growth in the first season when they formed long needles and stem units. Height growth by these seedlings was much less in the second season, however, as were needle length and stem unit number, but not stem unit length. Application of slow release N,P, and K fertilizer at planting improved shoot growth by bareroot trees more in the second season than the first. In contrast, the container-grown stock made a large shoot growth response to fertilization in both the first and the second seasons. The results are consistent with the hypothesis that, as root establishment proceeds, shoot growth tends to be limited by the supply, first of water, then of mineral nutrients. This implies that the early growth of planted spruce can be maximized by using stock with a high root growth capacity, or other adaptations to drought, and applying slow release fertilizer at planting. Observations on the white spruce revealed an acceleration in shoot growth by both stock types during the third season. This followed the establishment, by the end of the second season, of root systems several metres in diameter. A large difference in height: diameter ratio, observed at the time of planting, between the container-grown and bareroot white spruce disappeared entirely in the course of the first three growing seasons.

Effects of photoperiod and moisture availability on shoot growth, seedling morphology, and cuticle and epicuticular wax features of container-grown western hemlock seedlings

1989 ◽  
Vol 19 (1) ◽  
pp. 122-131 ◽  
Author(s):  
Conor O'Reilly ◽  
J. T. Arnott ◽  
John N. Owens
Keyword(s):  
Shoot Growth ◽  
Moisture Stress ◽  
Epicuticular Wax ◽  
Stress Conditions ◽  
Western Hemlock ◽  
Seedling Morphology ◽  
Growth Cessation ◽  
Moderate Drought ◽  
Morphological Variables ◽  
Collar Diameter

The influence of short-day and long-day photoperiods, and moderate drought stress (−1.0 MPa), all applied for 4 weeks beginning in mid-July, 1986, was studied on greenhouse-grown western hemlock (Tsugaheterophylla (Raf.) Sarg.) seedlings cultured in two Styroblock container cavity sizes. Shoot growth, morphology, and cuticle and epicuticular wax features were investigated. Weekly measurements of shoot growth were made from early June until growth cessation in October. Root collar diameter, shoot length, numbers of branches and needles, and needle lengths were recorded after shoot growth cessation in another subsample of trees. Shoot growth rapidly ceased under short days, whereas free growth continued under long days. Moisture stress had no effect on shoot growth phenology but significantly reduced final values for all morphological variables. The trends were similar in seedlings from both container sizes, but values were greater in those from the larger containers. Long days increased the total number of leaves and branches, especially under no moisture stress conditions. Under long days, stem unit and needle lengths were increased in the proximal portion of the shoot, whereas moisture stress alone reduced these values in the distal section of the shoot. Dormancy induction treatments had little effect on needle cuticle and epicuticular wax features, although fusion of wax rodlets in the stomata was less common under moisture stress conditions.

Bud development in coastal Douglas-fir seedlings in response to different dormancy-induction treatments

1993 ◽  
Vol 71 (10) ◽  
pp. 1280-1290 ◽  
Author(s):  
Joanne E. MacDonald ◽  
John N. Owens
Keyword(s):  
Cell Walls ◽  
Moisture Stress ◽  
Douglas Fir ◽  
Bud Development ◽  
Stress Treatment ◽  
Leaf Initiation ◽  
Short Day ◽  
Long Day ◽  
Dormancy Induction ◽  
Short Days

Bud development in response to different dormancy-induction treatments in coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) seedlings was investigated under commercial greenhouse conditions. There were three treatments: short day without moisture stress, short day with moisture stress, and long day with moisture stress. Within the first week in the short day treatments, neoformed-leaf initiation ended and bud-scale initiation began and ended. Rapid leaf initiation began in week 1 and was completed by week 5 for the short day with moisture stress treatment and week 6 for the short day without moisture stress treatment. Slow leaf initiation was completed by week 13. Crown cells became apparent within the pith during weeks 3–6; cell walls thickened between weeks 8 and 13. Within the first week of the long day with moisture stress treatment, neoformed-leaf initiation ended and bud-scale initiation began. Bud-scale initiation ended by week 3 or 4. Then slow leaf initiation began and continued until week 6. Rate of leaf initiation was rapid during weeks 8–10 and decreased slightly during weeks 10–13. By week 13, apical height had decreased markedly, indicating an imminent end to leaf initiation. Crown cells became apparent within the pith during weeks 5–13; cell walls thickened between weeks 10 and 13. Key words: bud development, dormancy induction, short days, moisture stress, Douglas-fir, seedlings.

Influence of dormancy induction treatments on western hemlock seedlings. I. Seedling development and stock quality assessment

1991 ◽  
Vol 21 (2) ◽  
pp. 164-174 ◽  
Author(s):  
S. C. Grossnickle ◽  
J. T. Arnott ◽  
J. E. Major ◽  
T. J. Tschaplinski
Keyword(s):  
Water Movement ◽  
Seedling Development ◽  
Western Hemlock ◽  
Root Temperature ◽  
Turgor Loss Point ◽  
Short Day ◽  
Long Day ◽  
Osmotic Potentials ◽  
Dormancy Induction ◽  
Needle Primordia

Western hemlock (Tsugaheterophylla (Raf.) Sarg.) seedlings were grown in a greenhouse and subjected to four dormancy induction treatments (DIT) (i.e., long-day dry, long-day wet, short-day dry, and short-day wet) during midsummer. In the late summer and fall, seedling development was monitored and it was found that (1) short-day DIT caused a rapid cessation of shoot growth; (2) short-day DIT caused rapid fall development of needle primordia, while long-day DIT took until midwinter to produce the same number of needle primordia; and (3) short-day DIT seedlings had lower saturated and turgor loss point osmotic potentials and greater maximum modulus of elasticity in October than long-day DIT. Seedlings were tested with a comprehensive stock quality assessment procedure just before late winter field planting. These tests showed the following: (1) morphological parameters: short-day DIT reduced shoot to root ratios; (2) pressure–volume analysis: short-day wet seedlings had the lowest osmotic potentials at saturation and turgor loss point; (3) soluble sugar analysis: greater levels of total soluble sugars were found in non water stressed DIT compared with water stressed DIT seedlings; (4) seedling water movement: short-day DIT seedlings had the lowest resistance to water movement at low root temperature (5 °C); (5) low root temperature response: short-day compared with long-day DIT seedlings had greater photosynthesis and stomatal conductance at low root temperatures; (6) root growth capacity: seedlings from all DIT were capable of growing roots at optimum root temperature (22 °C), but short-day compared with long-day DIT had greater root growth at low root temperatures; (7) drought stress response: short-day wet seedlings had the highest photosynthesis and stomatal conductance levels as predawn shoot water potentials decreased; and (8) frost hardiness: short-day wet seedlings had the least needle damage when tested at temperatures of −15 and −18 °C.

The growth of lodgepole pine seedlings raised under clear polythene cloches at five seedbed densities

1980 ◽  
Vol 10 (3) ◽  
pp. 426-428
Author(s):  
S. Thompson
Keyword(s):  
Plant Height ◽  
Dry Matter ◽  
Shoot Growth ◽  
Lodgepole Pine ◽  
Unit Length ◽  
Dry Weight ◽  
Dry Matter Production ◽  
Matter Production ◽  
Pine Seedlings ◽  
Foliage Weight

The components of shoot growth and dry matter production in 1 + 0 lodgepole pine (Pinuscontorta Dougl. ex Loud. spp. contorta) seedlings raised under clear polythene cloches for 12 weeks at five seedbed densities (180–720 plants/m2) were studied. The greater plant height found at the highest seedbed density was the result of increased stem unit length, not increased number of stem units. The increase in plant dry weight as seedbed density decreased was largely due to greater dry weight of roots, branchwood, and branch foliage, and not to increases in stemwood and stem foliage weight. Seedbed densities of less than 460 seedlings/m2 are required to produce yields of suitably sturdy seedlings in excess of 50% of the crop.

scholarly journals Night Interruption Lighting Is Beneficial in the Production of Plugs of Dahlia `Sunny Rose'

HortScience ◽  
2000 ◽  
Vol 35 (7) ◽  
pp. 1244-1246
Author(s):  
Garry Legnani ◽  
William B. Miller
Keyword(s):  
Shoot Growth ◽  
Physiological State ◽  
Dry Weight ◽  
Photon Flux ◽  
Photosynthetic Photon Flux ◽  
Fibrous Root ◽  
Shoot Dry Weight ◽  
Total Plant ◽  
Short Days ◽  
Foliar N Concentration

Experiments were conducted to evaluate effects of photoperiod on growth and dry-weight partitioning in Dahlia sp. `Sunny Rose' during both seedling (plug) production and subsequent production in 10-cm pots. Plugs were grown under short days [9-hour natural photosynthetic photon flux (PPF)] or long days (same 9-hour PPF plus a 4-hour night interruption with incandescent light). Total plant dry weight was unaffected by photoperiod; however, long days (LD) inhibited tuberous root development and increased shoot dry weight, fibrous root dry weight, leaf area, shoot length, and number of leaf pairs. Long days reduced plug production time by ≈1 week compared with short days (SD). Following transplanting to 10-cm pots, shoot growth and foliar development were superior under LD. There was no effect of photoperiod on foliar N concentration. The superior growth of LD plugs following transplanting can be attributed to the plant being in a physiological state conducive to shoot expansion instead of storage.

Embryo transcriptome and miRNA analyses reveal the regulatory network of seed dormancy in Ginkgo biloba

2020 ◽  
Author(s):  
Zhichao Jia ◽  
Beibei Zhao ◽  
Sian Liu ◽  
Zhaogeng Lu ◽  
Bang Chang ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Ginkgo Biloba ◽  
Regulatory Network ◽  
Regulatory Mechanism ◽  
Morphological Development ◽  
Morphophysiological Dormancy ◽  
Tree Seeds ◽  
Dormancy Induction ◽  
Release Processes

Abstract Seed dormancy is crucial for plant survival and prevents seed germination out of season. However, little is known about the regulatory mechanism of morphophysiological seed dormancy. Ginkgo biloba L. is one of the most ancient gymnosperms, and the completion of seed germination in this species requires cold and moist stratification. Here, we observed that at the mature seed stage, the embryo was not fully developed in G. biloba seeds. During dormancy stages, the length and weight of the embryo significantly increased, and nutrients accumulated in cotyledons. We further found that abscisic acid (ABA), gibberellic acid (GA), cytokinin and ethylene were integrated in the seed dormancy induction, maintenance and release processes, and GA biosynthesis and signaling transduction specifically act on dormancy release. Combining mRNA and miRNA analyses, we demonstrated that miRNA156 is involved in the regulation of morphophysiological dormancy. Our analyses revealed that G. biloba seed dormancy belongs to the ancestral morphophysiological dormancy type, which is not only regulated by the balance of ABA/GA, but also by other hormones associated with embryo morphological development, as well as genes related to embryo differentiation and development. These findings helped with elucidating the comprehensive regulatory network of morphophysiological dormancy in tree seeds.

The effect of reduced quantities of photosynthetically active radiation on Fraxinus pennsylvanica growth and architecture

1998 ◽  
Vol 76 (8) ◽  
pp. 1359-1365 ◽  
Author(s):  
G A Bartlett ◽  
W R Remphrey
Keyword(s):  
Photosynthetically Active Radiation ◽  
Shoot Growth ◽  
Unit Length ◽  
Shoot Biomass ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Seedling Morphology ◽  
Active Radiation ◽  
Shade Tolerant Species ◽  
Light Quantity

The quantity and quality of light have significant effects on tree growth and architecture that can be highly variable depending on the shade tolerance of the species. A study was conducted to determine the effect of decreased availability of photosynthetically active radiation (PAR) on the growth and architecture of green ash (Fraxinus pennsylvanica var. subintegerrima (Vahl) Fern.), a moderately shade-tolerant species. Twenty-four seedlings were planted in each of five shade treatments (4, 8, 20, 40, and 100% of full sun, respectively). Measurements made over a 2-year period revealed that with decreased PAR levels there was generally a reduction in leaf thickness, number of shoot units per shoot, shoot-unit length, shoot growth, branching frequency, lateral shoot growth, and shoot biomass. However, in moderate reductions of PAR, there were increases in shoot unit numbers, overall shoot length, and branch numbers. The overall effect of heavy shading was to produce a tree with little height growth and a poorly developed crown.Key words: Fraxinus, shading, seedling morphology, shoot unit, light quantity, architecture.

Influence of photoperiod and temperature on growth, gas exchange, and cold hardiness of yellow cypress stecklings

1994 ◽  
Vol 24 (8) ◽  
pp. 1608-1616 ◽  
Author(s):  
P. Puttonen ◽  
J.T. Arnott
Keyword(s):  
Cold Hardiness ◽  
Photosynthetic Efficiency ◽  
Shoot Growth ◽  
Net Photosynthesis ◽  
Height Growth ◽  
Morphological Development ◽  
Cool Temperature ◽  
Common Environment ◽  
Rooted Cuttings ◽  
H 20

Yellow cypress (Chamaecyparisnootkatensis (D. Don) Spach) stecklings (rooted cuttings) were acclimated for approximately 8 weeks under one of the following photoperiod–temperature treatments: 18 h/10 °C, 18 h/20 °C, 9 h/10 °C, 9 h/20 °C followed by deacclimation in a common environment of 12 h/20 °C for approximately 6 weeks. During acclimation and deacclimation, steckling morphological development, net photosynthesis, transpiration and leaf conductance, and midday shoot water potential were measured. Hardiness was determined by freeze-induced electrolyte leakage. Shoot growth was reduced more by short photoperiods (9 h) than by cool temperature (10 °C) as were net photosynthesis, stomatal conductance, transpiration, and photosynthetic efficiency. Photoperiod-induced cold hardening of shoots and height growth cessation were reversible in warm temperatures (20 °C) and 12-h days, indicating that hardiness induction treatments had no lasting effects on the growth or cold hardiness of this tree species.

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