THE IDENTIFICATION AND DISTRIBUTION OF PHYSIOLOGIC RACES OF ASCOCHYTA PISI LIB. IN CANADA

1957 ◽  
Vol 37 (4) ◽  
pp. 337-341 ◽  
Author(s):  
V. R. Wallen

Based upon the reactions of seven pea varieties selected for their suitability as differential hosts, four distinct physiologic races of Ascochyta pisi Lib. were found among 80 isolates of the fungus obtained from diseased pea plants and infected seeds from six provinces in Canada. The geographic distribution of each of the races was as follows: I and II from the Prairie Provinces; III the Georgian Bay area and central Ontario, and IV the Ottawa Valley and to a lesser extent central and western Ontario, Quebec, and Nova Scotia.

1990 ◽  
Vol 20 (12) ◽  
pp. 1859-1863 ◽  
Author(s):  
K. I. Mallett

A survey to identify Armillaria root rot pathogens, their host range, and geographic distribution was conducted in the Canadian prairie provinces. Collections of basidiocarps and isolates from the wood of gymptomatic or dead trees were made. Armillaria species were identified by interfertility testing and by the L-DOPA method. Three Armillaria species, A. ostoyae (Romagn.) Herink, A. sinapina Bérubé & Dessureault, and A. calvescens Bérubé & Dessureault, were identified. Armillariaostoyae was the most common species in both the subalpine and boreal forests and was found on a wide variety of coniferous and deciduous host species. Armillariasinapina was in both the boreal and subalpine forests but occurred primarily on deciduous host species. Armillariacalvescens was rare and was found only in the boreal forest on both coniferous and deciduous host species.


1946 ◽  
Vol 24c (2) ◽  
pp. 26-38 ◽  
Author(s):  
Margaret Newton ◽  
T. Johnson

During the period 1919 to 1944, 65 physiologic races were identified from a total of 4543 isolates derived from uredial collections of Puccinia graminis Pers. var. Tritici Erikss. & Henn. Forty-nine races were obtained in the Prairie Provinces from a study of 3475 isolates; 40 in Eastern Canada from 1013 isolates, and 12 in British Columbia from 55 isolates. During this period, the predominant races have shown notable fluctuations in their prevalence. Races 36, 17, and 21 were the most common races until shortly after 1930 and were largely responsible for the severe rust losses suffered by Marquis and other common wheats during the decade preceding that year. Races 34 and 49 were collected frequently from 1927 to about 1935. All of these races diminished greatly in their prevalence between 1930 and 1936, whereas race 56, which was first collected in Canada in 1931, has become the predominant race since 1934. It was this race that played a major part in the stem rust epiphytotic of 1935. Another recent change in the racial population was a recrudescence in 1940 of race17, which for several previous years had been of minor importance. In 1941 this race challenged the pre-eminent position of race 56 but receded again in succeeding years to minor significance.The distribution of races is somewhat similar but not identical in different parts of Canada. Races 36 and 21 have been relatively more common in the Prairie Provinces than in Eastern Canada, while the contrary is true of race 38. Only about a dozen of the 65 races collected in Canada have thus far assumed much economic importance, a few others may be considered of minor significance, but at least two-thirds of the races have been found only occasionally and have, for reasons not fully understood, failed to gain even a limited distribution.A comparison of the number of physiologic races collected in Eastern Canada and the Prairie Provinces, respectively, has indicated a somewhat greater variety of physiologic races in the former region, a condition that may perhaps be explained by the presence of the common barberry in many localities in Eastern Canada.


2019 ◽  
pp. 001-055
Author(s):  
Carmen Álvarez-Vázquez

This paper presents a taxonomic revision of filicopsid taxa from the lower to middle Westphalian strata of Nova Scotia and New Brunswick, Maritime Provinces of Canada. Most of the material represents sporadic historical collecting by Geological Survey of Canada (GSC) personnel, and specimens are in the GSC collections in Ottawa. Additional specimens are in the New Brunswick Museum at Saint John, the Fundy Geological Museum at Parrsboro, and the Joggins Fossil Institute at Joggins. Two specimens from outside Canada clarify specific characteristics. The revision involved the detailed examination of 20 adpression (mainly impression) taxa, of which one, Germera brousmicheae, is new. Detailed synonymy lists, with particular focus on records from Canada and the USA, facilitate a refinement of the stratigraphic and geographic distribution of these species. Most of the taxa from the Maritimes are the same as those from other parts of the paleoequatorial belt of Pennsylvanian times. The Maritimes record of filicopsid taxa closely resembles the filicopsid floras of western Europe, most notably the British Isles.


1954 ◽  
Vol 32 (4) ◽  
pp. 506-522 ◽  
Author(s):  
T. Johnson

Forty-two cultures of wheat stem rust (Puccinia graminis var. tritici Erikss. and Henn.), comprising 34 physiologic races, were subjected to selfing studies each of which involved the inoculation of barberry plants with the sporidia of a race, and the determination of the races in the uredial cultures derived from the aeciospores. In all of the cultures studied, the pathogenic properties expressed on the differential hosts appeared to be inherited according to the same principles. On the varieties Marquis and Kota (Triticum vulgare), pathogenicity of the races in the progeny tended to resemble that of the parent race. On Reliance (T. vulgare), avirulence was a dominant character, virulence a recessive one. On the durum wheats Arnautka, Mindum, and Spelmar, virulence was a dominant and avirulence a recessive character. On Einkorn (T. monococcum) and on Vernal (T. dicoccum), avirulence was dominant to virulence. In the progenies of some races, pathogenic variation occurred though it did not transgress the circumscribed limits of the parent race; the population therefore consisted chiefly of substrains (biotypes) of the same race.


Check List ◽  
2014 ◽  
Vol 10 (2) ◽  
pp. 397
Author(s):  
Robert G. Forsyth ◽  
Michael J. Oldham

The geographic distribution of Strobilops aeneus Pilsbry, 1926, a rare species in Canada, is reviewed and all known records are mapped. Two recent records, the only ones since 1941, are reported from the province of Ontario. One of these records represents a small range extension ca. 85 km north of the closest previous site. Specimens identified as S. aeneus from Ontario, New Brunswick, and Nova Scotia were re-examined and found to be another species.


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