STUDIES ON FUNGUS PARASITES OF STRAWBERRY LEAVES IN ONTARIO

1951 ◽  
Vol 29 (4) ◽  
pp. 299-315 ◽  
Author(s):  
Joan Fall
Keyword(s):  
North America ◽  
Seasonal Distribution ◽  
Symptom Expression ◽  
Middle Aged ◽  
Lesion Formation ◽  
Field Surveys ◽  
Leaf Blotch ◽  
Growing Seasons ◽  
Dendrophoma Obscurans ◽  
Mycosphaerella Fragariae

Four fungi were isolated from lesions on strawberry foliage in Ontario during the growing seasons of 1948 and 1949. They are Mycosphaerella fragariae (Tul.) Lindau. Diplocarpon carliana (Ell. & Ev.) Wolf, Dendrophoma obscurans (Ell. & Ev.) H. W. And., and Gnomonia fructicola (Arnaud) n. comb. (Zythia fragariae Laibach), and they cause the diseases known as leaf spot, leaf scorch, leaf blight and leaf blotch respectively. Apparently this is the first report of Zythiae fragariae in North America and of Dentrophoma obscurans in Canada. From field surveys, strawberry varieties were found to vary in resistance, especially to spot and scorch, and market differences in seasonal distribution of the diseases were also evident. Spot was most prevalent in the spring and fall; scorch increased in severity during the warmer months; and blight became prominent after the cropping period. As a result of inoculation with M. fragariae only the middle-aged leaves of vigorously growing strawberry plants developed lesions. Premier plants, although resistant to spot in the field, proved susceptible when artificially inoculated. Penetration by M. fragariae may occur without lesion formation if the temperature is below 15 °C. Symptom expression was best within the 20°–25 °C range. Adding strips of strawberry leaves to a suspension of conidia of Diplocarpon earliana greatly enhanced spore germination. Only leaves which are old or middle-aged develop scorch lesions, and these may be blotchy or diffuse depending on the variety. Dendrophoma obscurans appears to attack mainly the older leaves near the margins. The conidiophores are long and branched, the conidia slightly pointed, and the pyenidia are dark, leathery, and clumped in culture. Zythia fragariae has simple conidiophores, biguttulate conidia with rounded ends, and soft light brown pyenidia. The name Gnomonia fructicola is proposed for the fungus Gnomonia fragariae Klebahn form fructicola Arnaud because it is considered to be a different species from Gnomonia fragariae Klebahn.

scholarly journals The duration of the active phase on surge-type glaciers: contrasts between Svalbard and other regions

1991 ◽  
Vol 37 (127) ◽  
pp. 388-400 ◽  
Author(s):  
Julian A. Dowdeswell ◽  
Gordon S. Hamilton ◽  
Jon Ove Hagen
Keyword(s):  
Time Series ◽  
North America ◽  
Active Phase ◽  
Aerial Photographs ◽  
Polar Ice ◽  
Phase Duration ◽  
Field Surveys ◽  
The World ◽  
Glacier Surges ◽  
Fast Motion

AbstractMany glaciers in Svalbard and in other glacierized areas of the world are known to surge. However, the time series of observations required to assess the duration of fast motion is very restricted. Data on active-phase duration in Svalbard come from aerial photographs, satellite imagery, field surveys and airborne reconnaissance. Evidence on surge duration is available for eight Svalbard ice masses varying from 3 to 1250 km2. Worldwide, active-phase duration is recorded for less than 50 glaciers. Few observations are available on high polar ice masses. The duration of the active phase is significantly longer for Svalbard glaciers than for surge-type glaciers in other areas from which data are available. In Svalbard, the active phase may last from 3 to 10 years. By contrast, a surge duration of 1–2 years is more typical of ice masses in northwest North America, Iceland and the Pamirs. Ice velocities during the protracted active phase on Svalbard glaciers are considerably lower than those for many surge-type glaciers in these other regions. Mass is transferred down-glacier more slowly but over a considerably longer period. Svalbard surge-type glaciers do not exhibit the very abrupt termination of the active phase, over periods of a few days, observed for several Alaskan glaciers. The duration of the active phase in Svalbard is not dependent on parameters related to glacier size. The quiescent phase is also relatively long (50–500 years) for Svalbard ice masses. Detailed field monitoring of changing basal conditions through the surge cycle is required from surge-type glaciers in Svalbard in order to explain the significantly longer length of the active phase for glaciers in the archipelago, which may also typify other high polar ice masses. The finding that surge behaviour, in the form of active-phase duration, shows systematic differences between different regions and their environments has important implications for understanding the processes responsible for glacier surges.

Widespread infection of the Eastern red-spotted newt (Notophthalmus viridescens) by a new species of Amphibiocystidium, a genus of fungus-like mesomycetozoan parasites not previously reported in North America

Parasitology ◽  
2007 ◽  
Vol 135 (2) ◽  
pp. 203-215 ◽  
Author(s):  
T. R. RAFFEL ◽  
T. BOMMARITO ◽  
D. S. BARRY ◽  
S. M. WITIAK ◽  
L. A. SHACKELTON
Keyword(s):  
New Species ◽  
North America ◽  
Infectious Diseases ◽  
Emerging Infectious Diseases ◽  
Seasonal Distribution ◽  
Notophthalmus Viridescens ◽  
Amphibian Species ◽  
Mortality And Morbidity ◽  
Causative Agents ◽  
A New Species

SUMMARYGiven the worldwide decline of amphibian populations due to emerging infectious diseases, it is imperative that we identify and address the causative agents. Many of the pathogens recently implicated in amphibian mortality and morbidity have been fungal or members of a poorly understood group of fungus-like protists, the mesomycetozoans. One mesomycetozoan, Amphibiocystidium ranae, is known to infect several European amphibian species and was associated with a recent decline of frogs in Italy. Here we present the first report of an Amphibiocystidium sp. in a North American amphibian, the Eastern red-spotted newt (Notophthalmus viridescens), and characterize it as the new species A. viridescens in the order Dermocystida based on morphological, geographical and phylogenetic evidence. We also describe the widespread and seasonal distribution of this parasite in red-spotted newt populations and provide evidence of mortality due to infection.

Ascochyta paspali. [Descriptions of Fungi and Bacteria].

1985 ◽  
Author(s):  
E. Punithalingam
Keyword(s):  
New Zealand ◽  
North America ◽  
South America ◽  
Geographical Distribution ◽  
Paspalum Dilatatum ◽  
Leaf Blotch ◽  
Rain Splash

Abstract A description is provided for Ascochyta paspali. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Paspalum dilatatum (dallis grass), (and P. floridanum var. glabratum). DISEASE: Leaf blotch or streak of Paspalum spp. The visible symptoms are yellowish brown to grey lesions developing at the leaf tip and subsequently involving the entire leaf and sometimes the sheath. GEOGRAPHICAL DISTRIBUTION: Australasia (New Zealand); South America (Argentina) and North America (? USA). TRANSMISSION: The fungus occurs in Paspalum as an endophyte (Buchanan, 1984). The mycelium has been reported to grow systemically in xylem vessels of roots, leaves and inflorescences. Conidia are dispersed by rain splash and the fungus has been isolated from seeds. It has been suggested that the fungus might overwinter as mycelium within roots, crowns and infected seeds.

Seasonal distribution of the long-nosed bat (Leptonycteris curasoae) in North America: does a generalized migration pattern really exist?

1999 ◽  
Vol 26 (5) ◽  
pp. 1065-1077 ◽  
Author(s):  
Alberto Rojas-Martínez ◽  
Alfonso Valiente-Banuet ◽  
María del Coro Arizmendi ◽  
Ariel Alcántara-Eguren ◽  
Héctor T. Arita
Keyword(s):  
North America ◽  
Seasonal Distribution ◽  
Migration Pattern ◽  
Leptonycteris Curasoae

scholarly journals The duration of the active phase on surge-type glaciers: contrasts between Svalbard and other regions

1991 ◽  
Vol 37 (127) ◽  
pp. 388-400 ◽  
Author(s):  
Julian A. Dowdeswell ◽  
Gordon S. Hamilton ◽  
Jon Ove Hagen
Keyword(s):  
Time Series ◽  
North America ◽  
Active Phase ◽  
Aerial Photographs ◽  
Polar Ice ◽  
Phase Duration ◽  
Field Surveys ◽  
The World ◽  
Glacier Surges ◽  
Fast Motion

AbstractMany glaciers in Svalbard and in other glacierized areas of the world are known to surge. However, the time series of observations required to assess the duration of fast motion is very restricted. Data on active-phase duration in Svalbard come from aerial photographs, satellite imagery, field surveys and airborne reconnaissance. Evidence on surge duration is available for eight Svalbard ice masses varying from 3 to 1250 km2. Worldwide, active-phase duration is recorded for less than 50 glaciers. Few observations are available on high polar ice masses. The duration of the active phase is significantly longer for Svalbard glaciers than for surge-type glaciers in other areas from which data are available. In Svalbard, the active phase may last from 3 to 10 years. By contrast, a surge duration of 1–2 years is more typical of ice masses in northwest North America, Iceland and the Pamirs. Ice velocities during the protracted active phase on Svalbard glaciers are considerably lower than those for many surge-type glaciers in these other regions. Mass is transferred down-glacier more slowly but over a considerably longer period. Svalbard surge-type glaciers do not exhibit the very abrupt termination of the active phase, over periods of a few days, observed for several Alaskan glaciers. The duration of the active phase in Svalbard is not dependent on parameters related to glacier size. The quiescent phase is also relatively long (50–500 years) for Svalbard ice masses. Detailed field monitoring of changing basal conditions through the surge cycle is required from surge-type glaciers in Svalbard in order to explain the significantly longer length of the active phase for glaciers in the archipelago, which may also typify other high polar ice masses. The finding that surge behaviour, in the form of active-phase duration, shows systematic differences between different regions and their environments has important implications for understanding the processes responsible for glacier surges.

scholarly journals The Role of Micropropagation in Producing Specific Pathogen-tested Plants

HortScience ◽  
2008 ◽  
Vol 43 (1) ◽  
pp. 74-77 ◽  
Author(s):  
Adam Dale ◽  
Becky R. Hughes ◽  
Danielle Donnelly
Keyword(s):  
North America ◽  
Bacterial Pathogens ◽  
Visual Symptoms ◽  
Growing Seasons ◽  
Specific Pathogen

Micropropagation of strawberries is an extremely effective tool to rid strawberry plants of Colletotrichum infections. The continued health of these plants depends on a vigorous sanitation program throughout the nursery system in North America. Propagating healthy strawberry plants requires a series of steps: plants are micropropagated, virus-tested, screened for fungal and bacterial pathogens, and finally grown under strict guidelines for two growing seasons in propagator's fields. In the propagator's fields, the plants are inspected for visual symptoms of diseases and checked for trueness-to-type. This paper reviews the protocols used to develop specific pathogen-tested strawberry plants in Ontario and, where appropriate, discusses alternate techniques.

scholarly journals Distribution and identification of luteovirids affecting chickpea in Sudan

2021 ◽  
Vol 60 (2) ◽  
pp. 199-214
Author(s):  
Abdulrahman MOUKAHEL ◽  
Safaa G. KUMARI ◽  
Abdelmagid Adlan HAMED ◽  
Murray SHARMAN ◽  
Seid AHMED
Keyword(s):  
Phylogenetic Analyses ◽  
Dwarf Virus ◽  
Molecular Tools ◽  
High Similarity ◽  
Field Surveys ◽  
Growing Seasons ◽  
Chickpea Plant ◽  
Polymerase Chain ◽  
Pepper Vein Yellows Virus ◽  
Cotton Leafroll Dwarf Virus

In Sudan yellowing viruses are key production constraints in pulse crops. Field surveys were carried out to identify luteovirids affecting chickpea crops in the major production regions (Gezira Scheme and River Nile State). A total of 415 chickpea plant samples with yellowing and stunting symptoms were collected during the 2013, 2015 and 2018 growing seasons. Serological results (Tissue-blot immunoassays) showed that Luteoviridae and Chickpea chlorotic dwarf virus (CpCDV, genus Mastrevirus, family Geminiviridae) were the most common viruses, with rare infections with Faba bean necrotic yellows virus (FBNYV, genus Nanovirus, family Nanoviridae). Some samples reacted only with a broad-spectrum luteovirid monoclonal antibody (5G4-MAb), and others showed cross reactions between the specific monoclonal antibodies, suggesting the occurrence of new luteovirid variants. Serological results were confirmed by amplification with reverse transcription-polymerase chain reaction (RT-PCR) and sequencing of the partial coat protein gene. Molecular analyses provided a basic, sufficient and reliable characterization for four viruses affecting chickpea that belong to Polerovirus (family Luteoviridae). These were Cucurbit aphid-borne yellows virus (CABYV), Pepper vein yellows virus (PeVYV), Pepo aphid-borne yellows virus (PABYV) and Cotton leafroll dwarf virus (CLRDV), that shared high similarity with the type sequences. Phylogenetic analyses also revealed high similarity to luteovirid species. This study has established reliable, rapid and sensitive molecular tools for the detection of luteovirid species.

scholarly journals Survival and Growth of Amur maackia Seedlings Across North America

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 508B-508
Author(s):  
Anthony S. Aiello ◽  
William R. Graves
Keyword(s):  
North America ◽  
Field Trials ◽  
Stem Length ◽  
Site Location ◽  
Growing Seasons ◽  
Survival And Growth ◽  
Sibling Group ◽  
Selection Of ◽  
Half Sibling ◽  
Sibling Groups

Amur maackia (Maackia amurensis Rupr. & Maxim.) has potential for use in small, urban, or cold landscapes. Although Amur maackia is becoming increasingly popular, plants are currently grown from open-pollinated seed populations, and there has been no selection of cultivars. We have addressed the effects of climate on growth and have begun field trials for selection of horticulturally superior genotypes. In May 1995, a field trial near Ames was begun with 337 plants. These were selected from more than 2000 greenhouse-grown seedlings to represent 32 half-sibling seed groups from 16 arboreta across North America. After two growing seasons, the increase in stem length among seed groups ranged from 3% to 75%. Survival rate did not vary with seed group. In a related study, 30 plants from six half-sibling groups have been established at each of 10 sites in the U.S. and four in Canada to assess effects of location on survival and growth. The influence of seed group on survival after 1 year varied with the trial site location. Survival among combinations of half-sibling group and trial location ranged from 0% to 100% (mean = 54%). Half-sibling group and trial location affected growth without interaction. The greatest growth across locations, an 83% increase in stem length, was shown by seeds that originated from a tree at the Arnold Arboretum. At the 14 locations, changes in stem length over half-sibling groups varied from <0% in Ithaca, N.Y., to 179% in Puyallup, Wash.

Guignardia aesculi. [Descriptions of Fungi and Bacteria].

1993 ◽  
Author(s):  
E. Punithalingam
Keyword(s):  
Nova Scotia ◽  
North America ◽  
New Brunswick ◽  
Geographical Distribution ◽  
Horse Chestnut ◽  
Black Rot ◽  
Leaf Blotch ◽  
Main Host ◽  
Aesculus Glabra ◽  
Water Borne

Abstract A description is provided for Guignardia aesculi. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Aesculus glabra, A. hippocastanum (main host) (Hippocastanaceae). Several other species of Aesculus and subspecies including A. ambigua, A. arnoldiana, A. bushii, A. carnea, A. discolor, A. dupontii, A. hybrida, A. mississippiensis, A. mutabilis, A. neglecta, A. octandra, A. pavia, A. splendens, A. turbinata and A. woerlitzensis have been reported to be susceptible (Neely & Himelick, 1963; 50, 2509). DISEASE: Leaf blotch or black rot of Aesculus hippocastanum (horse chestnut) and other Aesculus species (5, 706; 28, 38; 64, 4521). GEOGRAPHICAL DISTRIBUTION: Europe (Austria, Belgium, France, Germany, Italy, Netherlands, Portugal, Romania, Switzerland, U.K., Yugoslavia); North America (Canada: Manitoba, New Brunswick, Nova Scotia, Ontario, Quebec; U.S.A. : Eastern U.S.A). TRANSMISSION: Presumably by water-borne conidia during wet conditions. Ascomata are produced on leaves left to over winter outside and both conidia and ascospores discharged from over wintered leaves have been reported to infect leaves of seedlings and produce blotch symptoms (Hudson, 1987).

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