Pollen-ovule ratios in seven species of Vaccinium (Ericaceae) and stamen structure in Vaccinium myrtilloides and Vaccinium vitis-idaea1This article is part of a Special Issue entitled “Pollination biology research in Canada: Perspectives on a mutualism at different scales”.

Botany ◽  
2012 ◽  
Vol 90 (7) ◽  
pp. 599-614 ◽  
Author(s):  
Danielle T. Stephens ◽  
Danielle E. Levesque ◽  
Arthur R. Davis
Keyword(s):  
Pollen Grains ◽  
Western Canada ◽  
Eastern Canada ◽  
Viscin Threads ◽  
Total Pollen ◽  
Vaccinium Myrtilloides ◽  
Facultative Xenogamy ◽  
Biology Research ◽  
Cell Thickness

Pollen-ovule (P/O) ratios were determined for five Vaccinium species (Ericaceae) native to eastern Canada (Nova Scotia: V. angustifolium, V. boreale, V. caespitosum, V. corymbosum, V. uliginosum), one in western Canada (Saskatchewan: V. myrtilloides), and one (V. vitis-idaea) from both provinces. Pollen, released at maturity as tetrads, was converted to total pollen grains per flower to yield P/O ratios ranging from 238 (V. caespitosum) to 2008 (V. vitis-idaea), but 736 for the latter in Saskatchewan. These P/O ratios are indicative of facultative autogamy to facultative xenogamy. Additionally, the structure of mature stamens and pollen tetrads was studied in V. myrtilloides and V. vitis-idaea. Each anther was functionally bilocular; had a single-cell thickness (i.e., epidermis) with regularly occurring papillae; lacked an endothecium; and possessed two distal, hollow tubules each terminating in a pore. Overall pollen grain viability was 76%–97% (V. myrtilloides) and 51%–93% (V. vitis-idaea), with about 20% of tetrads having only 1–3 grains viable, and 12% and 27% of tetrads entirely nonviable in V. myrtilloides and V. vitis-idaea, respectively. Pollen tetrads occasionally were connected by a sticky substance resembling pollenkitt, but viscin threads were absent. One instance of precocious (in situ) germination of tetrads was recorded within anthers of V. myrtilloides.

scholarly journals Some cytological, ecological and evolutionary aspects of pollination

2014 ◽  
Vol 65 (1-2) ◽  
pp. 11-16 ◽  
Author(s):  
Ettore Pacini ◽  
Gian G. Franchi
Keyword(s):  
Pollen Grains ◽  
Pollen Exine ◽  
Cohesive Forces ◽  
Viscin Threads ◽  
Tapetal Cells ◽  
Different Types ◽  
Pollen Diameter ◽  
Evolutionary Aspects

Different types of pollen dispersing units are described. The pollen of angiosperms may be dispersed in monads, tetrads, polyads, massulae or compact pollinia. The monads and tetrads may form larger clumps of pollen with the aid of the following substances: a) pollenkitt, a product of <em>in situ</em> degeneration of the tapetum; b) tryphine, a product of tapetal extra situm degeneration, found only in <em>Cruciferae</em>; c) elastoviscin, a highly viscous product of the degeneration of a limited number of tapetal cells, found only in certain <em>Orchidaceae</em>; d) viscin threads or sporopollenin filaments arising from the pollen exine. The number of pollen grains composing the clumps depends on pollen diameter and the cohesive forces holding the pollen grains together. The various types of pollen dispersing unit are discussed in relation to the type of pollination and number of ovules per ovary.

The High-Frequency Decay Slope of Spectra (Kappa) for M≥3.5 Earthquakes on Rock Sites in Eastern and Western Canada

2020 ◽  
Vol 110 (2) ◽  
pp. 471-488 ◽  
Author(s):  
Samantha M. Palmer ◽  
Gail M. Atkinson
Keyword(s):  
Ground Motion ◽  
Classical Method ◽  
Vertical Component ◽  
Western Canada ◽  
S Wave ◽  
Motion Modeling ◽  
Eastern Canada ◽  
General Observation ◽  
Anelastic Attenuation ◽  
Two Parameters

ABSTRACT Spectral decay of ground-motion amplitudes at high frequencies is primarily influenced by two parameters: site-related kappa (κ0) and regional Q (quality factor, inversely proportional to anelastic attenuation). We examine kappa and apparent Q-values (Qa) for M≥3.5 earthquakes recorded at seismograph stations on rock sites in eastern and western Canada. Our database contains 20 earthquakes recorded on nine stations in eastern Canada and 404 earthquakes recorded on eight stations in western Canada, resulting in 105 and 865 Fourier amplitude spectra, respectively. We apply two different methods: (1) a modified version of the classical S-wave acceleration method; and (2) a new stacking method that is consistent with the use of kappa in ground-motion modeling. The results are robust with respect to the method used and also with respect to the frequency band selected, which ranges from 9 to 38 Hz depending on the region, event, and method. Kappa values obtained from the classical method are consistent with those of the stacked method, but the stacked method provides a lower uncertainty. A general observation is that kappa is usually larger, and apparent Q is smaller, for the horizontal component in comparison to the vertical component. We determine an average regional κ0=7  ms (horizontal) and 0 ms (vertical) for rock sites in eastern Canada; we obtain κ0=19  ms (horizontal) and 14 ms (vertical) for rock sites in western Canada. We note that kappa measurements are quite sensitive to details of data selection criteria and methodology, and may be significantly influenced by site effects, resulting in large site-to-site variability.

Correlation of Grassy Lake and Cedar Lake ambers using infrared spectroscopy, stable isotopes, and palaeoentomology

2008 ◽  
Vol 45 (9) ◽  
pp. 1061-1082 ◽  
Author(s):  
Ryan C. McKellar ◽  
Alexander P. Wolfe ◽  
Ralf Tappert ◽  
Karlis Muehlenbachs
Keyword(s):  
Stable Isotopes ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Late Cretaceous ◽  
Western Canada ◽  
Long Distance ◽  
Geochemical Fingerprinting ◽  
Long Distance Transport ◽  
Distance Transport

The Late Cretaceous Grassy Lake and Cedar Lake amber deposits of western Canada are among North America’s most famous amber-producing localities. Although it has been suggested for over a century that Cedar Lake amber from western Manitoba may be a secondary deposit having originated from strata in Alberta, this hypothesis has not been tested explicitly using geochemical fingerprinting coupled to comparative analyses of arthropod faunal content. Although there are many amber-containing horizons associated with Cretaceous coals throughout Alberta, most are thermally mature and brittle, thus lacking the resilience to survive long distance transport while preserving intact biotic inclusions. One of the few exceptions is the amber found in situ at Grassy Lake. We present a suite of new analyses from these and other Late Cretaceous ambers from western Canada, including stable isotopes (H and C), Fourier transform infrared (FTIR) spectra, and an updated faunal compendium for the Grassy and Cedar lakes arthropod assemblages. When combined with amber’s physical properties and stratigraphic constraints, the results of these analyses confirm that Cedar Lake amber is derived directly from the Grassy Lake amber deposit or an immediate correlative equivalent. This enables the palaeoenvironmental context of Grassy Lake amber to be extended to the Cedar Lake deposit, making possible a more inclusive survey of Cretaceous arthropod faunas.

Kernel colour varies with cultivars and environments in barley

1998 ◽  
Vol 78 (2) ◽  
pp. 217-222 ◽  
Author(s):  
M. J. Edney ◽  
T. M. Choo ◽  
D. Kong ◽  
T. Ferguson ◽  
K. M. Ho ◽  
...  
Keyword(s):  
Hordeum Vulgare ◽  
Key Words ◽  
Western Canada ◽  
Net Blotch ◽  
Hordeum Vulgare L ◽  
Eastern Canada ◽  
Key Words Barley

Kernel colour is an important marketing trait for both malting and feed barleys. Therefore a study was initiated to investigate the kernel colour of 75 Canadian barley (Hordeum vulgare L.) cultivars at three locations (Charlottetown, Ottawa and Bentley) across Canada in 1991 and 1992. Kernel colour was measured by an Instrumar Colormet Spectrocolorimeter. Kernel colour was found to be brighter at the two locations in eastern Canada (Charlottetown and Ottawa) than at the location in western Canada (Bentley). Two-row cultivars on average were more discoloured than six-row cultivars; eastern two-row were more discoloured than western two-row. Covered barleys were less discoloured than hulless barleys in five of the six environments, but covered barleys at Bentley in 1992 were more discoloured than hulless barleys. Kernel discolouration appeared to be associated with susceptibility to net blotch for six-row cultivars. More studies are needed on kernel discolouration of barley. Key words: Barley, Hordeum vulgare, kernel colour

scholarly journals First Report of Phytophthora infestans Genotype US23 Causing Late Blight in Canada

Plant Disease ◽  
2011 ◽  
Vol 95 (7) ◽  
pp. 873-873 ◽  
Author(s):  
L. M. Kawchuk ◽  
R. J. Howard ◽  
R. D. Peters ◽  
K. I. Al-Mughrabi
Keyword(s):  
United States ◽  
Late Blight ◽  
Phytophthora Infestans ◽  
The United States ◽  
Western Canada ◽  
Eastern Canada ◽  
Disease Symptoms ◽  
Metalaxyl Sensitivity ◽  
Epidemiological Characteristics

Late blight is caused by the oomycete Phytophthora infestans (Mont.) de Bary and is one of the most devastating diseases of potato and tomato. Late blight occurs in all major potato- and tomato-growing regions of Canada. Its incidence in North America increased during 2009 and 2010 (2). Foliar disease symptoms appeared earlier than usual (June rather than July) and coincided with the identification of several new P. infestans genotypes in the United States, each with unique characteristics. Prior to 2007, isolates collected from potato and tomato crops were mainly US8 or US11 genotypes (1). However, P. infestans populations in the United States have recently experienced a major genetic evolution, producing isolates with unique genotypes and epidemiological characteristics in Florida and throughout the northeastern states (2). Recent discoveries of tomato transplants with late blight for sale at Canadian retail outlets prompted an examination of the genotypes inadvertently being distributed and causing disease in commercial production areas in Canada. Analysis of isolates of P. infestans from across Canada in 2010 identified the US23 genotype for the first time from each of the four western provinces (Manitoba, Saskatchewan, Alberta, and British Columbia) but not from eastern Canada. Allozyme banding patterns at the glucose phosphate isomerase (Gpi) locus indicated a 100/100 profile consistent with US6 and US23 genotypes (4). Mating type assays confirmed the isolates to be A1 and in vivo metalaxyl sensitivity was observed. Restriction fragment length polymorphic analysis of 50 isolates from western Canada with the multilocus RG57 sequence and EcoRI produced the DNA pattern 1, 2, 5, 6, 10, 13, 14, 17, 20, 21, 24, 24a, 25 that was indicative of US23 (3). The recently described P. infestans genotype US23 appears to be more aggressive on tomato, and although isolates were recovered from both tomato and potato, disease symptoms were often more severe on tomato. Results indicate that movement and evolution of new P. infestans genotypes have contributed to the increased incidence of late blight and that movement of the pathogen on retail plantlets nationally and internationally may provide an additional early season source of inoculum. A major concern is that the introduced new A1 populations in western Canada have established a dichotomy with the endogenous A2 populations in eastern Canada, increasing the potential for sexual recombination producing oospores and additional genotypes should these populations merge. References: (1) Q. Chen et al. Am. J. Potato Res. 80:9, 2003. (2) K. Deahl. (Abstr.) Phytopathology 100(suppl.):S161, 2010. (3) S. B. Goodwin et al. Curr. Genet. 22:107, 1992. (4) S. B. Goodwin et al. Phytopathology 88:939, 2004.

scholarly journals Airborne Pollen Records of Shomolu Local Government Area in Lagos State

2014 ◽  
Vol 6 (4) ◽  
pp. 428-432 ◽  
Author(s):  
Tiwalade A. ADENIYI ◽  
Peter A. ADEONIPEKUN ◽  
James D. OLOWOKUDEJO ◽  
Idowu S. AKANDE
Keyword(s):  
Local Government ◽  
Airborne Pollen ◽  
Pollen Grains ◽  
State University ◽  
Current Trends ◽  
Pollen Content ◽  
Lagos State ◽  
Total Pollen ◽  
Pollen Distribution ◽  
The Town

Data on the prevalence of pollen in the atmosphere is limited and almost non-existent for Lagos State and Nigeria. Pollen grains are known to be highly allergenic and thus they are potential causes of respiratory diseases. To investigate airborne incidence of pollen, so as to construct a pollen calendar and contribute to current trends in the development of aeropalynology/allergy study in Nigeria, three highly populated locations in Shomolu Local Government areas of Lagos State: University of Lagos, Bariga and Gbagada, were sampled. Aero-samplers were harvested monthly from January 2013 to December 2013. After acetolysis treatment and analysis, the total pollen count was 4393, belonging to 38 pollen taxa and 29 families. The main taxa include Poaceae, Cyperaceae, Amaranthaceae, Ludwigia and Alchornea. Monthly pollen counts were highest in October and lowest in June. Almost three-quarters of the total pollen content came from grasses and weeds. This composition reflects the ornamental and grassland flora of the town, as well as the natural vegetation surrounding the urban area. The total pollen concentration correlates positively with the temperature and negatively with the wind, rainfall and relative humidity, which was similar in the dominant taxa Amaranthaceae and Alchornea. Dominant taxa Cyperaceae and Ludwigia have significant positive correlation with wheezing cough. Results from this work will form the basis for a forecast service required to inform and educate the general public and allergy sufferers about pollen distribution in Lagos State.

L’ORGE DE PRINTEMPS SOPHIE

1981 ◽  
Vol 61 (1) ◽  
pp. 153-156
Author(s):  
C. A. ST-PIERRE ◽  
G. J. PELLETIER ◽  
J. P. DUBUC ◽  
H. R. KLINCK
Keyword(s):  
Powdery Mildew ◽  
Leaf Rust ◽  
Research Station ◽  
Western Canada ◽  
Barley Cultivar ◽  
Net Blotch ◽  
Average Yield ◽  
Eastern Canada ◽  
Breeder Seed ◽  
Late Maturity

In the Eastern Canada Co-op Barley test, Sophie has given an average yield of grain 1% higher than Mingo and Laurier, 3% higher than Bruce and 13% higher than Conquest. In the 1979 regional trials, it has given yields comparable to those of Loyola, the most widely grown cultivar in Quebec. From 295 comparisons with check cultivars, its yield was superior (P = 95%) in 23% of the comparisons, equal in 69% and inferior in 8% of the cases. This cultivar has also given higher yields than the checks in Western Canada. It is different mainly because of its late maturity. It is, on the average, 4 days later than the checks. It is also more resistant to lodging than Loyola and Laurier. Its straw strength is inferior to that of Bruce but almost equal to that of Conquest. Its weight per 1000 grains is higher than that of Conquest or Bruce, similar to that of Loyola or Mingo, and smaller than that of Laurier. It is moderately susceptible to powdery mildew. Bruce is, however, more resistant to this disease. Sophie had shown more resistance to leaf rust than the checks. It is also moderately susceptible to net blotch. This feed grain barley cultivar is a joint release between Laval University and the Agriculture Canada Research Station of Ste-Foy, Quebec. Breeder seed will be maintained by Université Laval at Ste-Foy.

Problematical taxonomic criteria in the Chytridiales: comparative morphology of 10 Entophlyctis sp. isolates

1971 ◽  
Vol 49 (6) ◽  
pp. 977-987 ◽  
Author(s):  
Tom Booth
Keyword(s):  
Synthetic Medium ◽  
Pollen Grains ◽  
Comparative Morphology ◽  
Western Canada ◽  
Review Of The Literature ◽  
Single Spore ◽  
Exact Identification ◽  
Established Species ◽  
Size And Structure

The criteria generally used in distinguishing taxa among the Chytridiales are size and structure of the zoospores, sporangium wall ornamentations, discharge papillae and tubes, presence or absence and structure of apophyses, nature and structure of rhizoids and number and position of rhizoidal axes, thallus development and relation to the substratum, monocentricity or polycentricity, and operculation. A review of the literature, however, reveals that these criteria are not sharply defined but highly variable and unstable for purposes of exact identification. This variability has become evident from a study of 10 single spore isolates of an Entophlyctis species collected in western Canada and the U.S.A. and grown on pollen grains and a synthetic medium. A comparison of the variations common to all isolates relates this species to several different established species of the genus which grade into one another and result in only three valid taxa, E. apiculata, E. crenata, and E. reticulospora. Also, the variations of the isolates relate this Entophlyctis sp. to different genera, subfamilies, families, and series, and make various current taxonomic dispositions and concepts of little value.

scholarly journals Apatite Stimulates the Deposition of Glomalin-Related Soil Protein in a Lowbush Blueberry Commercial Field

Agriculture ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 52 ◽  
Author(s):  
Maxime Paré ◽  
Pierre-Luc Chagnon ◽  
Joane Plourde ◽  
Valérie Legendre-Guillemin
Keyword(s):  
Mycorrhizal Fungi ◽  
Deposition Rates ◽  
Lowbush Blueberry ◽  
Protein Pool ◽  
Direct Linkage ◽  
Field Incubation ◽  
Vaccinium Myrtilloides ◽  
First Time ◽  
Soil Protein

Many wind-sensitive and unproductive soils could benefit from increased glomalin-related soil protein (GRSP), an operationally defined soil protein pool known to improve soil quality and nutrient storage. We expect at least part of this GRSP fraction to originate from fungal biomass. Although P-rich minerals such as apatite are known to increase C allocation from plants to mycorrhizal fungi, there are no studies directly linking apatite with GRSP. We investigated the effect of apatite on GRSP deposition rates in a cultivated field of wild lowbush blueberry (Vaccinium angustifolium Aiton; Vaccinium myrtilloides Michx.) in the Saguenay‒Lac-Saint-Jean region of Quebec (Canada). A field incubation technique (145 days) using sterilized porous sand bags (50 µm pores) was used to measure in situ easily extractable GRSP (EE-GRSP) deposition rates from bags with (n = 10) and without (n = 10) apatite. Half of the bags (n = 10) were also soaked in Proline® 480 SC (Bayer CropScience, Calgary, Alberta, Canada) (Prothioconazole) to determine if EE-GRSP deposition rates were affected by this commonly applied fungicide. Our results indicated that adding apatite into sand bags significantly increased (+70%) EE-GRSP deposition rates, whereas soaking the bags in fungicide had no significant effect. Although the direct linkage between GRSP and lowbush blueberry plants remains to be detailed, our study reports for the first time GRSP concentrations from lowbush blueberry soils. Implications of these findings are discussed.

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