Evaluation of Soybean Germplasm Accessions for Resistance to Phakopsora pachyrhizi Populations in the Southeastern United States, 2009-2012

Crop Science ◽  
2014 ◽  
Vol 54 (4) ◽  
pp. 1673-1689 ◽  
Author(s):  
David R. Walker ◽  
Donna K. Harris ◽  
Zachary R. King ◽  
Zenglu Li ◽  
H. Roger Boerma ◽  
...  
Keyword(s):  
United States ◽  
Southeastern United States ◽  
Phakopsora Pachyrhizi ◽  
Soybean Germplasm ◽  
Germplasm Accessions

scholarly journals Epidemiology of Soybean Rust in Soybean Sentinel Plots in Florida

Plant Disease ◽  
2011 ◽  
Vol 95 (6) ◽  
pp. 744-750 ◽  
Author(s):  
Heather M. Young ◽  
James J. Marois ◽  
David L. Wright ◽  
Dario F. Narváez ◽  
G. Kelly O'Brien
Keyword(s):  
United States ◽  
Growth Stage ◽  
Disease Incidence ◽  
Southeastern United States ◽  
Tropical Storm ◽  
Environmental Data ◽  
Soybean Rust ◽  
Phakopsora Pachyrhizi ◽  
Maturity Group ◽  
Rain Events

Since its discovery in the southeastern United States in 2004, soybean rust (SBR) has been variable from year to year. Caused by Phakopsora pachyrhizi, SBR epidemics in Florida are important to understand, as they may serve as an inoculum source for other areas of the country. This study examined the first disease detection date, incidence, and severity of SBR in relation to environmental data, growth stage, and maturity group (MG3, MG5, MG7) in soybean sentinel plots (225 m2) across north Florida from 2005 through 2008. The majority (91%) of the initial infections were observed in MG5 and MG7 soybeans, with plots not becoming infected until growth stage R4 or later. Precipitation was the principle factor affecting disease progress, where disease increased rapidly after rain events and was suppressed during dry periods. On average, plots became infected 30 days earlier in 2008 than 2005. In 2008, there was a significant increase in disease incidence and severity associated with the occurrence of Tropical Storm Fay, which deposited up to 380 mm of rainfall in north Florida. The results of this study indicate that climatic and environmental factors are important in determining the development of SBR in north Florida.

scholarly journals Comparative Susceptibility of Kudzu Accessions from the Southeastern United States to Infection by Phakopsora pachyrhizi

Plant Disease ◽  
2009 ◽  
Vol 93 (6) ◽  
pp. 593-598 ◽  
Author(s):  
M. R. Bonde ◽  
S. E. Nester ◽  
W. F. Moore ◽  
T. W. Allen
Keyword(s):  
United States ◽  
Southeastern United States ◽  
Average Diameter ◽  
Economic Loss ◽  
The United States ◽  
Soybean Rust ◽  
Phakopsora Pachyrhizi ◽  
Wide Range ◽  
The Individual ◽  
A Site

Soybean rust, caused by Phakopsora pachyrhizi, was first discovered in the continental United States in the fall of 2004. The potential for economic loss in the United States hinges largely on whether or not the pathogen can survive winters in the absence of soybean. Kudzu (Pueraria lobata) is known to be a host for P. pachyrhizi in Asia and South America and is widely distributed in the southern United States. This study examined reactions of kudzu collected from several areas of the southeastern United States to three isolates of P. pachyrhizi, one each from Alabama, Louisiana, and Brazil. Susceptible tan (TAN) lesions, resistant reddish-brown (RB) lesions, and immune (IM) response, previously described on soybean, were produced on kudzu based on the evaluation of 125 plants. However, in contrast to soybean, the RB response on kudzu was common, with approximately 50% frequency. IM responses to at least one isolate were observed on five individual plants, and two plants were immune to all three pathogen isolates used in the test. TAN lesions averaged 3.2 uredinia per lesion with an average diameter per uredinium of 121 μm. In contrast, RB lesions had an average of 0.3 uredinia per lesion with an average uredinial diameter of 77 μm. In 25 of 39 (64%) instances in which multiple plants were tested from a site, each reacted the same to the individual pathogen isolates. This suggested a tendency for plants at specific sites to be genetically identical with respect to rust reaction. Only 19 of 125 (15%) individual plants produced a different reaction to one isolate than to the other two isolates. When four kudzu plants previously shown to produce only TAN lesions to P. pachyrhizi isolates Alabama 04-1, Brazil 01-1, and Louisiana 04-1 were inoculated with eight additional isolates from several areas of the world, all 11 isolates produced only TAN lesions. Likewise, when five other plants previously shown to produce only RB lesions when inoculated with the three isolates were inoculated with the 11 isolates, all produced only RB lesions. These results suggest that susceptibility or resistance to P. pachyrhizi in individual kudzu plants often is broad, extending over a wide range of P. pachyrhizi isolates.

Evaluation of USDA Soybean Germplasm Accessions for Resistance to Soybean Rust in the Southern United States

Crop Science ◽  
2011 ◽  
Vol 51 (2) ◽  
pp. 678-693 ◽  
Author(s):  
D. R. Walker ◽  
H. R. Boerma ◽  
D. V. Phillips ◽  
R. W. Schneider ◽  
J. B. Buckley ◽  
...  
Keyword(s):  
United States ◽  
Soybean Rust ◽  
Southern United States ◽  
Soybean Germplasm ◽  
Germplasm Accessions

scholarly journals Effects of Daily Temperature Highs on Development of Phakopsora pachyrhizi on Soybean

2012 ◽  
Vol 102 (8) ◽  
pp. 761-768 ◽  
Author(s):  
M. R. Bonde ◽  
S. E. Nester ◽  
D. K. Berner
Keyword(s):  
United States ◽  
Southeastern United States ◽  
The United States ◽  
Daily Temperature ◽  
Soybean Rust ◽  
Limiting Factor ◽  
Climatic Data ◽  
Phakopsora Pachyrhizi ◽  
Diurnal Temperature ◽  
National Climatic Data Center

Although considerable information exists regarding the importance of moisture in the development of soybean rust, little is known about the influence of temperature. The purpose of our study was to determine whether temperature might be a significant limiting factor in the development of soybean rust in the southeastern United States. Soybean plants infected with Phakopsora pachyrhizi were incubated in temperature-controlled growth chambers simulating day and night diurnal temperature patterns representative of the southeastern United States during the growing season. At 3-day intervals beginning 12 days after inoculation, urediniospores were collected from each plant and counted. The highest numbers of urediniospores were produced when day temperatures peaked at 21 or 25°C and night temperatures dipped to 8 or 12°C. When day temperatures peaked at 29, 33, or 37°C for a minimum of 1 h/day, urediniospore production was reduced to 36, 19, and 0%, respectively, compared with urediniospore production at the optimum diurnal temperature conditions. Essentially, no lesions developed when the daily temperature high was 37°C or above. Temperature data obtained from the National Climatic Data Center showed that temperature highs during July and August in several southeastern states were too high for significant urediniospore production on 55 to 77% of days. The inhibition of temperature highs on soybean rust development in southeastern states not only limits disease locally but also has implications pertaining to spread of soybean rust into and development of disease in the major soybean-producing regions of the Midwestern and northern states. We concluded from our results that temperature highs common to southeastern states are a factor in the delay or absence of soybean rust in much of the United States.

Does Enhancing Mind Perception Affect Conspiracy Belief?

2019 ◽  
Author(s):  
Jorge Noguera
Keyword(s):  
United States ◽  
Southeastern United States ◽  
Social Discourse ◽  
Psychological Processes ◽  
Social Psychological ◽  
Conspiracy Theories ◽  
Mind Perception ◽  
Mixed Anova ◽  
Interaction Term ◽  
The Mind

This study was conducted to determine the effectiveness of a novel mind perception manipulation. Mind perception is currently theorized to be an essential aspect of a number of human social psychological processes. Thus, a successful manipulation would allow for the causal study of those processes. This manipulation was created in an attempt to explore the downstream impact of mind perception on the endorsement of conspiracy theories. Conspiracy theories are steadily becoming more and more prominent in social discourse. Endorsement of conspiracy theories are beginning to show real world ramifications such as a danger to human health (e.g., in the anti-vaccination movement). A sample of college students (valid N = 53) from a large rural institution in the southeastern United States participated for course credit. These participants completed a mind perception pretest, were randomly assigned to either the manipulation in question (in which participants are asked to consider the ‘mind’ of several targets and write their thoughts about them) or the control condition, and then they completed a posttest. The mixed ANOVA revealed that the interaction term between Time and Condition was not significant. Because the manipulation did not work, other analyses were aborted, in accord with the pre-registration. My Discussion focuses on the procedures and potential shortcomings of this manipulation, in an effort to lay the groundwork for a successful one.

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