Female gametophyte and embryo development of black spruce along a shore-hinterland climatic gradient of a recently created reservoir, northern Quebec

1999 ◽  
Vol 77 (1) ◽  
pp. 61-69 ◽  
Author(s):  
Luc Sirois ◽  
Yves Bégin ◽  
Johanne Parent
Keyword(s):  
Embryo Development ◽  
Picea Mariana ◽  
Female Gametophyte ◽  
Black Spruce ◽  
Growing Season ◽  
Seed Maturation ◽  
Cooling Effect ◽  
Sigmoid Function ◽  
Embryo Maturation ◽  
Degree Days

The development of female gametophytes and embryos in relation to cumulative growing degree-days was followed to see if the postulated cooling influence of the Robert-Bourassa reservoir (LG2, northern Quebec) slowed the reproductive process of black spruce (Picea mariana (Mill.) B.S.P.). During the 1996 growing season, three to five developing seed cones were harvested 11 times on nine trees distributed along a shore-hinterland gradient of the northern shore of the reservoir. The daily thermal sum (degree-days > 5°C) in the seed cone zone of the same trees was also monitored to describe the female gametophyte and embryo development of this species as a function of heat sum. The 23 developmental stages identified in this study confirm that the female gametophyte and embryo of P. mariana develop according to the same pattern exhibited by other Picea spp. These stages, although unequal in duration, succeeded each other according to a sigmoid function of the temperature sum. Direct temperature measurements taken 0, 25, and 100 m from the shore of the Robert-Bourassa reservoir suggest the interior trees experienced 107 more degree-days > 5°C than the shoreline trees during seed maturation. Although gametophyte development of the shoreline trees was delayed early in the growing season (Kruskall-Wallis, p = 0.05), this delay does not persist afterward. Despite the net cooling effect of the Robert-Bourassa reservoir, all studied trees achieved embryo maturation in 1996. During this growing season, the warmest since 1977, it took embryos 800-940 degree-days to mature. The shoreline trees reached this temperature threshold later than interior trees. It is suggested that the cooling effect of the Robert-Bourassa reservoir could contribute to the inhibition of embryo maturation in shoreline trees during growing seasons with less than 800 degree-days.Key words: black spruce, climate change, cone development, northern boreal forests, Picea mariana, seed maturation.

scholarly journals LEAFY COTYLEDON1 expression in the endosperm enables embryo maturation in Arabidopsis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jingpu Song ◽  
Xin Xie ◽  
Chen Chen ◽  
Jie Shu ◽  
Raj K. Thapa ◽  
...  
Keyword(s):  
Seed Development ◽  
Embryo Development ◽  
Growth Regulators ◽  
Seed Maturation ◽  
Embryo Maturation ◽  
Leafy Cotyledon1 ◽  
Functional Relevance ◽  
Necessary And Sufficient ◽  
Zygote Stage

AbstractThe endosperm provides nutrients and growth regulators to the embryo during seed development. LEAFY COTYLEDON1 (LEC1) has long been known to be essential for embryo maturation. LEC1 is expressed in both the embryo and the endosperm; however, the functional relevance of the endosperm-expressed LEC1 for seed development is unclear. Here, we provide genetic and transgenic evidence demonstrating that endosperm-expressed LEC1 is necessary and sufficient for embryo maturation. We show that endosperm-synthesized LEC1 is capable of orchestrating full seed maturation in the absence of embryo-expressed LEC1. Inversely, without LEC1 expression in the endosperm, embryo development arrests even in the presence of functional LEC1 alleles in the embryo. We further reveal that LEC1 expression in the endosperm begins at the zygote stage and the LEC1 protein is then trafficked to the embryo to activate processes of seed maturation. Our findings thus establish a key role for endosperm in regulating embryo development.

OCCURRENCE OF DEATHWATCH CONE BEETLE, ERNOBIUS BICOLOR WHITE (COLEOPTERA: ANOBIIDAE), IN CONES OF BLACK SPRUCE, PICEA MARIANA (MILL.) B.S.P., IN NOVA SCOTIA

1993 ◽  
Vol 125 (2) ◽  
pp. 403-404 ◽  
Author(s):  
J.D. Sweeney ◽  
G. Gesner ◽  
G. Smith
Keyword(s):  
Nova Scotia ◽  
Picea Mariana ◽  
Black Spruce ◽  
Growing Season ◽  
Extensive Survey ◽  
Seed Yields

An extensive survey of black spruce, Picea mariana (Mill.) B.S.P., in Newfoundland in 1978 disclosed that up to 50% of the old cones remaining on the trees were damaged by the deathwatch cone beetle, Ernobius bicolor White (Schooley 1983; White 1983). This beetle infests black spruce cones produced in the previous year's growing season and also damages cones in storage. Eggs are deposited between the scales and larvae feed within the cone and pupate in the fall or the following spring; their feeding can reduce extracted seed yields by one-half (Schooley 1983).

Comparison of growth and physiology of layers and naturally established seedlings of black spruce in a boreal cutover in Quebec

1999 ◽  
Vol 29 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Raynald Paquin ◽  
Hank A Margolis ◽  
René Doucet ◽  
Marie R Coyea
Keyword(s):  
Water Potential ◽  
Picea Mariana ◽  
Black Spruce ◽  
Net Photosynthesis ◽  
Growing Season ◽  
Height Growth ◽  
Total Height ◽  
Acclimation Period ◽  
Use Efficiency ◽  
Growth Of Seedlings

Growth and physiology of layers versus naturally established seedlings of boreal black spruce (Picea mariana (Mill.) BSP) were compared 15 years after a cutover in Quebec. During the first 8 years, height growth of seedlings was greater than that of layers, averaging 10.4 and 7.0 cm/year, respectively. For the last 5 years, annual height growth of layers and seedlings did not differ (25 cm/year; p > 0.05). Over the entire 15-year period, total height growth of seedlings (251 cm) was greater than that of layers (220 cm), although total height did not differ (p > 0.05) over the last 6 years. During the 15th growing season, there were no differences (p > 0.05) for predawn shoot water potential, stomatal conductance, net photosynthesis, intercellular to ambient CO2 ratio, water use efficiency, and hydraulic conductance between layers and seedlings. For diurnal shoot water potential, seedlings showed slightly less stress than layers on two of the four sampling dates. Thus, in the first few years following the cutover, the slower growth observed for layers indicated that they had a longer acclimation period following the cutover. Afterwards, similar height growth, total height, and physiological characteristics of the two regeneration types indicated that layers can perform as well as naturally established seedlings.

scholarly journals RELATIONSHIP BETWEEN SITE INDEX AND FOLIAGE NITROGEN AT TWO CROWN LEVELS FOR MATURE BLACK SPRUCE

1964 ◽  
Vol 40 (2) ◽  
pp. 169-174 ◽  
Author(s):  
J. D. Gagnon
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Growing Season ◽  
Site Index ◽  
Site Quality

The concentration of nitrogen in current year lateral needles of 122 mature dominant and codominant black spruce trees (Picea mariana Mill.) growing on different site qualities has been studied. Analyses carried out on needles collected at the end of the growing season and within two feet of both the top and base of the crown indicated that samples obtained from either position on the crown can be related to site index or site quality. It seems, therefore, that the concentration of nitrogen in needles from the lower branches is as good a criterion of growth or productivity as that in the needles from the upper branches.

Somatic embryo maturation, germination, and soil establishment of plants of black and white spruce (Picea mariana and Picea glauca)

1990 ◽  
Vol 68 (12) ◽  
pp. 2583-2589 ◽  
Author(s):  
S. M. Attree ◽  
T. E. Tautorus ◽  
D. I. Dunstan ◽  
L. C. Fowke
Keyword(s):  
Abscisic Acid ◽  
Somatic Embryo ◽  
Picea Mariana ◽  
Picea Glauca ◽  
Black Spruce ◽  
White Spruce ◽  
Embryo Maturation ◽  
Black And White ◽  
Somatic Embryo Maturation

Somatic embryo maturation, germination, and soil establishment frequencies were compared for two conifer species, white and black spruce (Picea glauca and Picea mariana). The comparison of the two species regenerated and established in soil under the same conditions showed black spruce to be the most responsive. Shorter exposure times to 32 μM abscisic acid were not as effective as maturation on a medium containing 16 μM abscisic acid for 28 days. This gave similar maturation frequencies for the two species (6–8%), and germination frequencies of 64% for white spruce and over 73% for black spruce. Over 1800 black and white spruce plantlets were recovered, and more than 400 were transferred from in vitro to nonsterile conditions. Sixty percent (160) of the black spruce plantlets survived transfer and continued to grow vigorously. By comparison only 18% (29) of the white spruce plantlets survived, and half of these rapidly produced dormant buds and underwent no further shoot growth. White spruce plants that did not produce dormant buds grew vigorously. These results indicate that there are large differences in the ability of these closely related species to respond to plantlet establishment following regeneration from somatic embryos, and that black spruce is highly responsive to micropropagation by this method. Key words: Picea glauca, Picea mariana, somatic embryogenesis, maturation, germination, soil establishment.

Seasonal growth of black spruce and tamarack roots in an Alberta peatland

1993 ◽  
Vol 71 (2) ◽  
pp. 359-360 ◽  
Author(s):  
Timothy S. S. Conlin ◽  
Victor J. Lieffers
Keyword(s):  
Root Growth ◽  
Key Words ◽  
Picea Mariana ◽  
Black Spruce ◽  
Growing Season ◽  
Plant Roots ◽  
Larix Laricina ◽  
Soil Cores ◽  
Seasonal Growth

Seasonal growth of black spruce (Picea mariana Mill. BSP) and tamarack (Larix laricina (Du Roi) K. Koch) roots in an Alberta peatland were assessed by measuring growth into emplaced soil cores that did not contain plant roots. Five cores were positioned 1 m from the base of each tree and 10 replicates of this treatment were used for each species. Sequential lifting of these cores during the growing season showed that root growth by these species did not begin until midsummer. Tamarack root growth was restricted to August and September, while black spruce root growth continued into October. Key words: flooding, Larix laricina, peatland, phenology, Picea mariana, temperature, root growth.

Photosynthesis of black spruce, jack pine, and trembling aspen after artificially induced frost during the growing season

1998 ◽  
Vol 28 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Manuel Lamontagne ◽  
Hank Margolis ◽  
Francine Bigras
Keyword(s):  
Populus Tremuloides ◽  
Picea Mariana ◽  
Tree Species ◽  
Pinus Banksiana ◽  
Black Spruce ◽  
Recovery Period ◽  
Growing Season ◽  
Jack Pine ◽  
Trembling Aspen ◽  
Monitoring Period

Light-saturated photosynthesis following artificial frosts was monitored for black spruce (Picea mariana (Mill.) BSP), jack pine (Pinus banksiana Lamb.), and trembling aspen (Populus tremuloides Michx.). None of the species exposed to -9°C in May or to -6 and -9°C in August recovered within the 23- and 14-day monitoring periods, respectively. Black spruce and jack pine treated at -6°C in May recovered within 5 and 23 days, respectively. Black spruce treated at -3°C in August recovered within 10 days. Frosts were applied to the upper and lower canopies of mature black spruce and jack pine in June and to mature trembling aspen in July. For black spruce, the lower canopy did not recover whereas the upper canopy partially recovered over the 10-day monitoring period. For jack pine and trembling aspen, there were no differences in recovery between canopy levels. Jack pine treated at -5.5°C recovered within the 10-day monitoring period whereas at -8.5°C, it only partially recovered. Although recovery period varied with species, phenological state, and frost temperature, gradual recovery of photosynthesis over 5-21 days seems a reasonable modelling algorithm for boreal tree species when growing season frosts lower than -3°C occur. However, cooling rates in our experiments were greater than those that normally occur in nature.

Spatial analysis of black spruce (Picea mariana (Mill.) B.S.P.) radial growth response to climate in northern Québec – Labrador Peninsula, Canada

2015 ◽  
Vol 45 (3) ◽  
pp. 343-352 ◽  
Author(s):  
A. Nicault ◽  
E. Boucher ◽  
D. Tapsoba ◽  
D. Arseneault ◽  
F. Berninger ◽  
...  
Keyword(s):  
Cluster Analysis ◽  
Boreal Forest ◽  
Spatial Scale ◽  
Tree Ring ◽  
Tree Rings ◽  
Picea Mariana ◽  
Black Spruce ◽  
Growing Season ◽  
Positive Influence ◽  
Large Spatial Scale

The aim of this study is to analyze the relationships between black spruce (Picea mariana (Mill.) B.S.P.) growth and climate at a large spatial scale in North America’s northeastern boreal forest. The study area (approximately 700 000 km2) is located in the taiga zone of the Quebec – Labrador Peninsula. A network of tree-ring chronologies from 93 black spruce populations was developed. A hierarchical cluster analysis was conducted to analyze tree-ring series affinities, and response functions were calculated to analyze relationships between tree rings and climate. The cluster analysis results showed well-marked spatial affinities among the tree-ring series. These affinities were strongly linked with the spatial variability of the relationships between tree rings and climate. The interannual growth variations were governed mainly by the temperature variables that preceded the growing season (November (negative influence), December–January (positive influence), and April (positive influence)). The growing-season temperature (July temperature) mainly influenced the northernmost populations. Relationships between tree rings and climate in the northeastern boreal forest varied at a large spatial scale. This variability was expressed by a north–south contrast, which appears to be related to a temperature gradient, and an east–west contrast linked to a humidity gradient, which favors winter snow cover.

Stabilité mécanique et caractéristiques racinaires de plants de fortes dimensions de Picea mariana produits en récipients ou à racines nues

2010 ◽  
Vol 86 (4) ◽  
pp. 469-476 ◽  
Author(s):  
Nelson Thiffault
Keyword(s):  
Picea Mariana ◽  
Mechanical Stability ◽  
Black Spruce ◽  
Growing Season ◽  
Diameter Ratio ◽  
Soil Scarification ◽  
Root Stock ◽  
Stock Type ◽  
Nursery Practices ◽  
Bare Root

In Québec (Canada), large planting stock are used for reforestation of high-competition sites, sometimes in combination with soil scarification. Large conifer seedlings are typically produced in containers >300 cm3, or as bare-root stock. Nursery practices are expected to influence seedling mechanical stability. We measured large containerized and bare-root black spruce (Picea mariana) seedling stability (resistance to winching), and characterized their root architecture, during their seventh growing season since planting in scarified or non-scarified plots devoid of any competing vegetation. We detected no significant stock type or scarification effect on seedling height, diameter, height/diameter ratio, stability, total number of roots and adventive roots. Occurrences of root deformations, as well as vertical and horizontal root distributions, were not influenced significantly by the treatments. The height/diameter ratio was the sole significant predictor of the resistance to winching. Our results indicate that the use of either large containerized or large bare-root stock has limited silvicultural consequences. In this context, the choice of large stock type should be based on other factors, such as handling constraints.Key words: black spruce, reforestation, stock type, scarification, root system

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