The acceleration of jack pine seed development

1987 ◽  
Vol 17 (11) ◽  
pp. 1408-1415 ◽  
Author(s):  
Robert A. Cecich ◽  
Edmund O. Bauer
Keyword(s):  
Reproductive Cycle ◽  
Shoot Elongation ◽  
Growth Conditions ◽  
Jack Pine ◽  
Growing Seasons ◽  
Natural Photoperiod ◽  
Germination Success ◽  
Accelerated Growth ◽  
Terminal Shoot ◽  
Viable Seeds

The time from emergence of an ovulate strobilus to collection of viable seeds can be reduced to as little as 9 months instead of the usual 16 months spread over two growing seasons. The procedure is called the "shortened reproductive cycle." Two-year-old jack pine (Pinusbanksiana Lamb.) seedlings, grown under accelerated growth conditions, were brought into a greenhouse in the fall, where the environment simulated natural photoperiod and temperature conditions encountered during a growing season, including the approach of fall and winter. Ovulate strobili that subsequently emerged were pollinated and "2nd-year" cones, derived from those strobili, were collected the following September. The yield of filled seeds per cone was low and germination success was variable. The seedlings derived from the shortened reproductive cycle appeared to be normal and produced their own ovulate strobili 14 months after germination. Exposure to the greenhouse environment stimulated pollen production but decreased production of ovulate strobili 1 year after transplanting to the nursery. Flowering during the shortened reproductive cycle procedure was further promoted with gibberellin A4/7 application at the end of terminal shoot elongation in the greenhouse during the winter. Ovulate strobili were observed 6 months later in the nursery.

Applied gibberellin A4/7 increases ovulate strobili production in accelerated growth jack pine seedlings

1981 ◽  
Vol 11 (3) ◽  
pp. 580-585 ◽  
Author(s):  
Robert A. Cecich
Keyword(s):  
Growth Conditions ◽  
Jack Pine ◽  
Fourfold Increase ◽  
Pine Seedlings ◽  
Accelerated Growth

Jack pine (Pinusbanksiana Lamb.) seeds were sown in October, January, and March, and the seedlings were cultured under accelerated growth conditions in a greenhouse. At biweekly intervals, from May 15 to August 15, they were transplanted to a nearby nursery and sprayed with GA4/7 or GA4/7 + NAA. The following spring a fourfold increase in flowering was noted in trees receiving either of the GA4/7 treatments. Trees in the March sowing did not flower. The data suggest that the increased flowering was caused by GA4/7-mediated differentiation of lateral long-branch primordia into ovulate strobili.

Flowering in a jack pine seedling seed orchard increased by spraying with gibberellin A4/7

1983 ◽  
Vol 13 (6) ◽  
pp. 1056-1062 ◽  
Author(s):  
Robert A. Cecich
Keyword(s):  
Growing Season ◽  
Seed Orchard ◽  
Shoot Elongation ◽  
Jack Pine ◽  
Ethanol Solution ◽  
Bud Development ◽  
Seedling Seed Orchard ◽  
Female Flowering ◽  
Accelerated Growth ◽  
Control Tree

Jack pine (Pinusbanksiana Lamb.), in a 3-year-old orchard established with accelerated-growth seedlings, were sprayed with gibberellin A4/7 (GA4/7) in an Aromox–ethanol solution during the 1981 growing season. Seven treatment periods were evaluated: the entire growing season, shoot elongation, bud development, early (first half) and late (second half) shoot elongation, and early and late bud development. Three concentrations of GA4/7 (200, 400, and 600 mg•L−1) were applied in all combinations with treatment periods. Three treatments increased female flowering: 400 and 600 mg•L−1 GA4/7 sprayed the entire growing season and 600 mg•L−1 sprayed during bud development. The number of pollen clusters was increased by spraying 400 and 600 mg•L−1 GA4/7 during any treatment period except early shoot elongation and late bud development or during shoot elongation (400 mg•L−1 only). The 200 mg•L−1 GA4/7 increased pollen clusters only if sprayed during early bud development or the entire growing season. The percentage of trees bearing pollen increased with all concentrations of GA4/7. The 1982 shoot growth of trees sprayed in 1981 during shoot elongation or the entire growing season (all GA4/7 levels pooled) was significantly less than control-tree growth or that of trees in the other treatment periods. The best treatment for increasing both male and female strobili was 600 mg•L−1 GA4/7 sprayed during bud development.

scholarly journals Grain yield and competitive ability against weeds in modern and heritage common wheat cultivars are differently influenced by sowing density

2017 ◽  
Vol 11 ◽  
Author(s):  
Mariateresa Lazzaro ◽  
Ambrogio Costanzo ◽  
Dalia Hosam Farag ◽  
Paolo Bàrberi
Keyword(s):  
Grain Yield ◽  
Common Wheat ◽  
Weed Suppression ◽  
Strong Impact ◽  
Wheat Cultivars ◽  
Modern Cultivar ◽  
Weed Biomass ◽  
Growing Seasons ◽  
Viable Seeds ◽  
Crop Stand

Sowing density can have a strong impact on crop stand development during wheat growing cycle. In organic and low-input agriculture, and therefore with minimum or nil use of chemical herbicides, increased sowing density is expected to affect not only grain yield but also weed suppression. In this study we tested, under Mediterranean conditions, six common wheat cultivars (three modern and three heritage) and two three-component mixtures (arranged by combining the three modern or the three heritage cultivars). The different crop stands were tested at sowing densities of 250 (low) and 400 (high, similar to standard sowing density used by local farmers) viable seeds m-2 for two growing seasons. We did not detect a significant effect of crop stand diversity (single cultivars vs mixtures) on grain yield and weed suppression. Differences were ascribed to type of cultivars used (heritage vs modern). Compared to high sowing density, in modern cultivars grain yield did not decrease significantly with low sowing density whereas in heritage cultivars it increased by 15.6%, possibly also because of 21.5% lower plant lodging. Weed biomass increased with low sowing density both in heritage and modern cultivar crop stand types. However, heritage crop stands had, on average, a lower weed biomass (56%) than modern crop stands. Moreover, weed biomass in heritage crop stands at low density (6.82 ± 1.50 g m-2) was lower than that of modern cultivars at the same sowing density (15.54 ± 3.35 g m-2), confirming the higher suppressive potential of the former. We can conclude that lower sowing density can be advisable when using heritage crop stands as it keeps productivity while decreasing plant lodging and maintaining weeds under control.

The effects of summer shoot production on height growth components of seedlings of California red and white fir

1992 ◽  
Vol 22 (5) ◽  
pp. 690-698 ◽  
Author(s):  
Stephen W. Hallgren ◽  
John A. Helms
Keyword(s):  
Soil Moisture ◽  
Growing Season ◽  
Shoot Elongation ◽  
Height Growth ◽  
Shoot Morphology ◽  
Apical Dome ◽  
White Fir ◽  
Shoot Production ◽  
Terminal Shoot ◽  
Needle Primordia

Morphogenesis of the terminal shoot was studied in 2-year-old seedlings of California red fir (Abiesmagnifica A. Murr.) and two elevational sources of white fir (Abiesconcolor (Gord. & Glend.) Lindl.). Seedlings were either watered or left unwatered during the growing season in order to produce different shoot morphologies and seedlings with and without a summer shoot. Under favorable soil moisture, the frequency of summer shoot production was 32, 53, and 82% for red fir and high- and low-elevation white fir, respectively. Drought from mid-May to mid-September reduced summer shoot production to less than 1% in both species. Spring shoot morphology was not an indicator of capacity to produce a summer shoot. Rate of primordium production was directly related to apical dome diameter. However, when the normal spring increase in apical dome diameter was arrested by summer shoot elongation, the rate of primordium production appeared to be unaffected. Although the apical and subapical meristems were active at the same time, they did not appear to be antagonistic. The major effects of producing a summer shoot were as follows: (i) elongation of 60–120% more intemodes in the current growing season, (ii) production of 15–40% more needle primordia in the overwintering bud, (iii) production of 30–60% more primordia annually, and (iv) increase in the percentage of total primordium production that developed into needles from 60% to 75–80%.

scholarly journals Gen dan QTL Pengendali Umur pada Kedelai

2016 ◽  
Vol 9 (2) ◽  
pp. 85
Author(s):  
I Made Tasma
Keyword(s):  
Flowering Time ◽  
Germplasm Collection ◽  
Reproductive Traits ◽  
Floral Organ ◽  
Growth Conditions ◽  
Gene Markers ◽  
Soybean Germplasm ◽  
Growing Seasons ◽  
Short Period ◽  
Model Plant Arabidopsis Thaliana

<p>Traits that control time of flowering and<br />maturity in soybean determine harvesting time of a soybean<br />cultivar. In Indonesia, early maturing soybean cultivars are<br />important at short period growing seasons due to the water<br />shortage in dry planting season. Shorter period of growing<br />season would increase the crop harvest index. Genetic<br />diversity of the present soybean germplasm collection is<br />low. Diversity improvement through introduction from<br />countries with four seasons faced difficulty due to<br />differences in growth adaptability. Technology for developing<br />germplasm with a broader adaptation will facilitate<br />germplasm movement from a more diverse environmental<br />growth. The objective of this review was to describe how<br />the time of flowering and maturity are controlled in soybean.<br />The review is supported by flowering time mechanism of<br />the model plant Arabidopsis thaliana as the genetics of<br />flowering time has been intensively studied in this model<br />plant. Transition from vegetative to reproductive development<br />is the outcome of the activation of genes responsible<br />for floral organ formation. Initial activation is generally the<br />result of environmental cues indicating the appropriate time<br />to flower. Studies from Arabidopsis showed that transition<br />from vegetative to reproductive stage is complex involving<br />many genes and several genetic pathways. In soybean, time<br />of flowering and maturity are controlled by at least nine<br />genes, E1 to E8 and Dt1. The genes interact with daylength<br />and temperature. Major and minor QTLs controlling the<br />traits were identified using various mapping populations.<br />The major QTLs were detected at various populations with<br />diverse genetic backgrounds tested at diverse environmenttal<br />conditions. Some of the QTLs were associated with the E<br />genes and some others were not. Several Arabidopsis<br />flowering gene homologous sequences were also mapped<br />on the soybean genome. The E gene markers and the QTLs<br />with large effect for reproductive traits are breeder targets<br />for breeding and development of soybean photoperiod<br />insensitive germplasm. Genes for flowering time isolated<br />from Arabidopsis can be used to develop transgenic<br />soybean with broader adaptation. Technology for development<br />of soybean germplasm with broader adaptation will<br />facilitate the soybean germplasm movement from diverse<br />environmental growth conditions to support systematic and<br />sustainable national soybean breeding programs.</p>

Early Survival and Growth of Russian Pinus sylvestris L. in Canada

1970 ◽  
Vol 46 (4) ◽  
pp. 325-328
Author(s):  
A. H. Teich ◽  
M. J. Holst
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
High Performance ◽  
Jack Pine ◽  
Stem Form ◽  
Growth And Survival ◽  
Growing Seasons ◽  
Survival And Growth ◽  
Continental Climate ◽  
Better Than

Scots pine provenances from Russia were grown in Ontario at Longlac, Dorset and Chalk River, and in Saskatchewan at Prince Albert and Indian Head. After eight growing seasons in the field all provenances survived well. The three tallest, Orel, Woronesh and Kiev provenances, grew considerably taller than the others, and at Prince Albert, where native jack pine was also grown, the growth and survival of these provenances was also better than that of jack pine. If further studies show that this high performance persists and that stem form is commercially acceptable, seedlings from these three provenances may be useful for reforestation in those parts of Canada with a continental climate.

scholarly journals Five Years of Vegetation Succession Following Vegetation Management Treatments in a Jack Pine Ecosystem

2000 ◽  
Vol 17 (3) ◽  
pp. 100-109 ◽  
Author(s):  
D.G. Pitt ◽  
Andrée E. Morneault ◽  
Philip Bunce ◽  
F.Wayne Bell
Keyword(s):  
Pinus Banksiana ◽  
Jack Pine ◽  
Height Growth ◽  
Volume Index ◽  
Deciduous Tree ◽  
Stem Volume ◽  
Deciduous Trees ◽  
Growing Seasons ◽  
Fern Species ◽  
Crown Closure

Abstract Five years of data on vegetation dynamics and succession are provided for six operational release treatments applied to three 2- to 4-yr-old jack pine (Pinus banksiana Lamb.) plantations in central Ontario. Treatments included 3 yr of annual noncrop vegetation removal, conventional aerial spray with glyphosate (1.42 kg ae/ha), ground application of glyphosate with a mist blower, basal-bark application of triclopyr, motor-manual cutting (brush saw), and no treatment. Conventional aerial spraying and annual removal resulted in the greatest jack pine crop growth, with trees exceeding 90% crown closure, 7 cm in groundline diameter, and 3 m in height (stem volume index = 5.1 dm³) after 5 growing seasons. The cover of herbaceous plants was highest (30–50%) in the aerial spray plots during the observation period. Deciduous tree, shrub, and fern species remained well represented on these plots, although total cover and height were low (≤ 35% and 1 m, respectively). Mist-blower and brush-saw plots contained mid-sized pine (3.5 dm³) with 69% crown closure. In contrast, untreated and basal-bark plots contained the smallest pine (2.3 dm3 and 31% crown closure), likely caused by heavy competition and herbicide damage, respectively. On mist-blower and basal-bark plots, good height growth was observed on untreated deciduous trees; low-shrub and fern cover remained high (46 and 30%, respectively); and herbaceous cover increased gradually to 22%. On brush-saw plots, recovery of woody cover was rapid, but height growth was relatively slow. Deciduous trees and tall shrubs dominated untreated sites (> 70% cover) by the end of the fifth growing season. Successional trends suggest that aerial spray and annual removal treatments will produce pure jack pine stands at maturity; mist blower, basal bark, and brush-saw treatments may produce mixedwood stands; and untreated plots will likely be dominated by hardwoods. North. J. Appl. For. 17(3):100–109.

scholarly journals Jack Pine Regeneration Following Postcut Burning under Seed Trees in Central Saskatchewan

1988 ◽  
Vol 64 (4) ◽  
pp. 315-319 ◽  
Author(s):  
Z. Chrosciewicz
Keyword(s):  
Populus Tremuloides ◽  
Growth Rates ◽  
Pinus Banksiana ◽  
Forest Regeneration ◽  
Black Spruce ◽  
Timber Harvest ◽  
Jack Pine ◽  
Growing Seasons ◽  
Pine Regeneration ◽  
Slash Burning

An experimental burn in conjunction with a seed-tree system was successful in regenerating jack pine (Pinus banksiana Lamb.) on a fresh to somewhat moist upland, loamy till, cutover site in central Saskatchewan. About 20 well-formed, uniformly spaced seed trees per hectare were left standing during timber harvest. The ignition of logging slash was carried out under preselected weather and fuel conditions so that favorable seedbeds and adequate seed dispersal from the seed trees were produced. Four growing seasons after burning, jack pine stocking by 4-m2 quadrats was 90% with 12 195 seedlings/ha. Aspen (Populus tremuloides Michx.), to a lesser degree black spruce (Picea mariana [Mill.] B.S.P.), and other companion tree species also regenerated with the pine. Various seedbed and regeneration characteristics as well as height growth rates are discussed. Key words: Pinus banksiana, slash burning, seed-tree system, forest regeneration, growth rates, central Saskatchewan.

Multiple-trait selection in jack pine

1991 ◽  
Vol 21 (4) ◽  
pp. 439-445 ◽  
Author(s):  
G. W. Adams ◽  
E. K. Morgenstern
Keyword(s):  
Genetic Relationships ◽  
Selection Index ◽  
Genetic Correlations ◽  
Jack Pine ◽  
Height Growth ◽  
Quality Traits ◽  
Multiple Trait ◽  
Growing Seasons ◽  
Stem Straightness ◽  
Variance And Covariance Components

Open-pollinated jack pine (Pinusbanksiana Lamb.) families were evaluated at four sites in New Brunswick after seven growing seasons for height growth, crown quality, stem straightness, branch angle, and relative branch diameter. Variance and covariance components were estimated to determine heritability of traits and genetic correlations between traits. Results indicated that there is a negative genetic correlation between height growth and all other traits. Selection based on height growth alone would result in degradation of quality traits of secondary economic importance at this age. A restricted selection index approach was examined for family roguing in seedling seed orchards because of the adverse genetic relationships between traits. Such an approach may be used to hold secondary quality traits constant, although some loss in maximum potential genetic gain in height at 7 years is incurred.

Shoot morphology and shoot growth potential in 1-year-old Scots pine seedlings

1981 ◽  
Vol 11 (4) ◽  
pp. 789-795 ◽  
Author(s):  
S. Thompson
Keyword(s):  
Scots Pine ◽  
Shoot Growth ◽  
Growing Season ◽  
Shoot Elongation ◽  
Growth Potential ◽  
Shoot Morphology ◽  
Growing Seasons ◽  
Pine Seedlings

When seedlings of a single seed source of Scots pine (Pinussylvestris L.) were raised for 26 weeks in a naturally lit, heated greenhouse, two types of shoot morphology were observed. Type 1 was that normally found in 1-year-old seedlings. Type 2 had a shoot morphology similar to that of seedlings raised outdoors for two growing seasons. When compared with type 1 plants, type 2 plants had an earlier start to shoot elongation, set their buds earlier, and stopped shoot elongation sooner. After one growing season, type 2 plants were shorter, had fewer stem units for shoot elongation in the second season, but carried a greater foliage biomass than 1-year-old type plants. After two seasons they remained shorter. Thus, plant rearing practices which result in the production of seedlings with this type of shoot morphology arc undesirable.The relationship between early "budsct," shoot morphology, and plant height suggests that the proportion of seedlings with a 2-year-old shoot morphology after one growing season in a heated greenhouse may be used as an early test for height growth potential in seed origins and possibly in progenies of north temperate pine species.

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