SEARCH FOR BIOLOGICAL RACES IN AMPHOROPHORA AGATHONICA HOTTES ON RED RASPBERRIES

1971 ◽  
Vol 51 (2) ◽  
pp. 81-85 ◽  
Author(s):  
R. H. CONVERSE ◽  
HUGH A. DAUBENY ◽  
R. STACE-SMITH ◽  
LOUISE M. RUSSELL ◽  
E. J. KOCH ◽  
...  
Keyword(s):  
Natural Populations ◽  
Statistical Analyses ◽  
Red Raspberry ◽  
Amphorophora Agathonica

The red raspberry cultivars ’Latham,’ ’Viking,’ ’Newburgh,’ ’Willamette,’ ’Sumner,’ ’Rideau’ and ’Lloyd George’ were tested for their differential abilities to support colonies of the aphid Amphorophora agathonica. These cultivars were grown at Agassiz, B.C. and Burlington, Vt., and counts of the natural populations of A. agathonica that developed on each cultivar except Lloyd George were subjected to statistical analyses. Latham, Viking, and Newburgh differed significantly in relative numbers of aphids between the two locations. The numbers on Willamette and Sumner were relatively similar. Rideau and Lloyd George were immune at each location. This suggests that the populations at the two locations belonged to the same race with respect to their ability to colonize red raspberry cultivars. The differences observed in Latham, Viking, and Newburgh might relate to variations in genotypes of the race.

Location of the Mechanism of Resistance to Amphorophora agathonica (Hemiptera: Aphididae) in Red Raspberry

2012 ◽  
Vol 105 (4) ◽  
pp. 1465-1470 ◽  
Author(s):  
D. M. Lightle ◽  
M. Dossett ◽  
E. A. Backus ◽  
J. C. Lee
Keyword(s):  
Red Raspberry ◽  
Mechanism Of Resistance ◽  
Amphorophora Agathonica

scholarly journals Biotypic Diversity and Resistance to the Raspberry Aphid Amphorophora agathonica in Pacific Northwestern North America

2012 ◽  
Vol 137 (6) ◽  
pp. 445-451 ◽  
Author(s):  
Michael Dossett ◽  
Chaim Kempler
Keyword(s):  
British Columbia ◽  
North America ◽  
North American ◽  
Rubus Idaeus ◽  
Red Raspberry ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Production Region ◽  
Northwestern North America ◽  
Amphorophora Agathonica

Resistance to colonization by the raspberry aphid (Amphorophora agathonica Hottes) has been an important objective in North American red raspberry (Rubus idaeus L.) breeding programs since the 1930s because of its effectiveness in controlling the spread of aphid-transmitted viruses in red raspberry. The most widely used source of resistance in North America has been the gene Ag1 from ‘Lloyd George’. The widespread use of Ag1 to control aphids led to the appearance of a resistance-breaking biotype in British Columbia, Canada, in 1990. Our objective was to identify biotypes of A. agathonica present in the commercial red raspberry production region of southwestern British Columbia and northwestern Washington and determine what sources of resistance may still be effective against this pest. We collected 12 aphid isolates and screened them against 15 raspberry cultivars and four selections. Although it has been widely believed that only two biotypes (regular and Ag1-breaking) of A. agathonica were present in the region, we identified six distinct biotypes and characterized them by their ability or inability to colonize a differential set of raspberry cultivars. This has confirmed the loss of previously recognized and unrecognized sources of resistance in some cultivars. The data also support the presence of a seventh biotype that has not yet been observed. In addition, we confirmed resistance from three sources of wild North American red raspberries that hold up to each of these biotypes. Our results will serve as a guide for future efforts to characterize the prevalence of different aphid biotypes in the region and the identification of new sources of resistance for breeding.

High-voltage electron microscopy of maxillary gland of spirochete-infected brine shrimp: lesion of efferent tubule

1988 ◽  
Vol 46 ◽  
pp. 362-363
Author(s):  
G. E. Tyson ◽  
M. J. Song
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Brine Shrimp ◽  
Natural Populations ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Infected Adult

Natural populations of the brine shrimp, Artemia, may possess spirochete- infected animals in low numbers. The ultrastructure of Artemia's spirochete has been described by conventional transmission electron microscopy. In infected shrimp, spirochetal cells were abundant in the blood and also occurred intra- and extracellularly in the three organs examined, i.e. the maxillary gland (segmental excretory organ), the integument, and certain muscles The efferent-tubule region of the maxillary gland possessed a distinctive lesion comprised of a group of spirochetes, together with numerous small vesicles, situated in a cave-like indentation of the base of the tubule epithelium. in some instances the basal lamina at a lesion site was clearly discontinuous. High-voltage electron microscopy has now been used to study lesions of the efferent tubule, with the aim of understanding better their three-dimensional structure.Tissue from one maxillary gland of an infected, adult, female brine shrimp was used for HVEM study.

Effect of acid deposition on trichome morphology and dogwood anthracnose biology

1992 ◽  
Vol 50 (1) ◽  
pp. 840-841
Author(s):  
Kyle T. Thornham ◽  
R. Jay Stipes ◽  
Randolph L. Grayson
Keyword(s):  
Acid Deposition ◽  
Disease Incidence ◽  
Natural Populations ◽  
Tree Disease ◽  
Flowering Dogwood ◽  
Discula Destructiva ◽  
Disease Induction ◽  
Dogwood Anthracnose ◽  
Trichome Morphology ◽  
Precipitation Events

Dogwood anthracnose, caused by Discula destructiva (1), is another new catastrophic tree disease that has ravaged natural populations of the flowering dogwood (Cornus florida) in the Appalachians over the past 15 years, and the epidemic is prognosticated to continue (2). An estimated 9.5 million acres have been affected, primarily in the Appalachian Mountains, from VA southwards, alone, and an estimated 50% of all dogwoods in PA have been killed. Since acid deposition has been linked experimentally with disease induction, and since the disease incidence and severity are more pronounced at higher elevations where lower pH precipitation events occur, we investigated the effect of acidic foliar sprays on moiphologic changes in the foliar cuticle and trichomes (3), the initial sites of infection and foci of Discula sporulation.

Structuring Situational Information

2015 ◽  
Vol 20 (3) ◽  
pp. 176-189 ◽  
Author(s):  
John F. Rauthmann
Keyword(s):  
Statistical Analyses ◽  
Current Work ◽  
Common Language ◽  
Road Map ◽  
Taxonomic Approach ◽  
Situational Information

Abstract. There is as yet no consensually agreed-upon situational taxonomy. The current work addresses this issue and reviews extant taxonomic approaches by highlighting a “road map” of six research stations that lead to the observed diversity in taxonomies: (1) theoretical and conceptual guidelines, (2) the “type” of situational information studied, (3) the general taxonomic approach taken, (4) the generation of situation pools, (5) the assessment and rating of situational information, and (6) the statistical analyses of situation data. Current situational taxonomies are difficult to integrate because they follow different paths along these six stations. Some suggestions are given on how to spur integrated taxonomies toward a unified psychology of situations that speaks a common language.

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