scholarly journals Survival of Oospores of Phytophthora capsici in Soil

Plant Disease ◽  
2013 ◽  
Vol 97 (11) ◽  
pp. 1478-1483 ◽  
Author(s):  
M. Babadoost ◽  
C. Pavon
Keyword(s):  
Phytophthora Capsici ◽  
Soil Surface ◽  
Soil Samples ◽  
Burial Depth ◽  
Infested Soil ◽  
University Of Illinois ◽  
Field Environment ◽  
Dry Soil ◽  
The University ◽  
Depth Of Burial

This study assessed survival of Phytophthora capsici oospores in soil in Illinois. Soils differing in texture and other characteristics were collected from four Illinois Counties (Champaign, Gallatin, Madison, and Tazewell), equilibrated to –0.3 MPa, and infested with oospores of P. capsici at a density of 5 × 103 oospores/g of dry soil. Samples (25 g) of the infested soil were placed in 15-μm mesh polyester bags, which were sealed and placed at 2-, 10-, and 25-cm depths in 15.3-cm-diameter PVC tubes containing the same field soil as the infested bags. Tubes were buried vertically in the ground at the University of Illinois Vegetable Research Farm in Champaign in October 2004. Soil samples were assayed for recovery and germination of oospores 1 day and 3, 6, 12, 24, 30, 36, and 48 months after incorporation of oospores into the soil. Overall, the percentage of oospore recovery and the percentage of germination of oospores were not affected significantly by soil source and burial depth but both the oospore recovery and oospore germination were significantly (P = 0.001) affected by the duration of oospore burial. The rate of oospore recovery from soil samples was 61.06, 16.69, 10.28, 1.05, 0.30, 0.06, 0.05, and 0.004% after 1 day and 3, 6, 12, 24, 30, 36, and 48 months, respectively, following incorporation of oospores into the soil; and mean oospore germination was 47.17, 30.53, 21.33, 15.64, 7.42, 2.67, 2.61, and 0.00%, respectively. Survival of P. capsici oospores was compared in soil samples stored in a laboratory at 22°C versus on the soil surface or buried 2, 10, or 25 cm deep in a field. Oospores were recovered 1, 3, 6, 12, and 24 months after incorporation for both storage locations. The percentage of oospores recovered from samples stored in the laboratory was significantly (P = 0.004) greater than recovery from samples stored in the field, regardless of the depth of burial. Twenty-four months after incorporation of oospores, 26.52% of oospores were recovered from soil samples in the laboratory, whereas only 0.12% of oospores were recovered from soil samples in the field. Overall, the percentages of germination of oospores recovered from samples in the laboratory and field over 24 months were not significantly different. In both experiments, germinated oospores produced mycelia, sporangia, and zoospores, and were virulent on ‘California Wonder’ bell pepper. This study showed that oospores of P. capsici can survive and remain virulent in Illinois soils for more than 36 months but oospores were no longer viable after 48 months in soil in a field environment.

The Effects of Depth and Duration of Seed Burial on Viability, Dormancy, Germination, and Emergence of Ivyleaf Speedwell (Veronica hederifolia)

2006 ◽  
Vol 20 (2) ◽  
pp. 438-444 ◽  
Author(s):  
Husrev Mennan ◽  
Bernard H. Zandstra
Keyword(s):  
Seedling Emergence ◽  
Soil Surface ◽  
Burial Depth ◽  
Triphenyltetrazolium Chloride ◽  
Primary Dormancy ◽  
Dry Storage ◽  
Winter Annual ◽  
High Level ◽  
Depth Of Burial ◽  
Over Time

Experiments were conducted to investigate the effects of depth and duration of burial on seasonal germination, primary and secondary dormancy, viability, and seedling emergence of ivyleaf speedwell (Veronica hederifoliaL.) seeds. The seeds were buried at 0, 5, 10, or 20 cm and retrieved from the field at monthly intervals. The exhumed seeds were germinated at 5 C. In the second experiment, seeds were stored in the laboratory after harvest and tested for germination at monthly intervals. In each experiment, nongerminated seeds were treated with triphenyltetrazolium chloride at monthly intervals to test their viability. The effects of stratification and burial depth on seedling emergence were observed for 1 yr. The seeds exhumed from the soil were dormant at the beginning of the experiment and exhibited dormancy/nondormancy/conditional dormancy cycling throughout the experiment. Depth of burial and time affected seed germination. Seeds retrieved from the soil surface germinated well initially, but germination decreased as depth of burial increased. In the dry storage experiment, seeds had a high level of primary dormancy, and viability decreased over time. Seedling emergence decreased when depth of burial increased. Seedlings emerged nonuniformly throughout the year and demonstrated typical winter annual characteristics.

scholarly journals Detecting the Possibility of Soil Pollution with Radon Emissions for an Area Located within Baghdad University Campus- AL-Jadiriyah

2019 ◽  
pp. 1985-1996
Author(s):  
Wadhah Mahmood Shakir Al-Khafaji ◽  
Ruwaida Tariq Mehdi ◽  
Basim Khalaf Rejah
Keyword(s):  
Soil Pollution ◽  
Clayey Soil ◽  
Root Zone ◽  
Soil Surface ◽  
Geiger Counter ◽  
Soil Samples ◽  
Contour Maps ◽  
Surface Survey ◽  
Dump Yard ◽  
The University

This research deals  with the detection of possible surface soil pollution by radon emissions for an area located inside the university of Baghdad campus at AL-Jadiriyah / Baghdad. The area is about 5625 m2 and located near the College of Science for Women. The area used as construction rubbles dump yard in the past, while recently it is covered with Silty - Clayey soil furnished with grass and used as a playground. A surface survey performed on October 2018 by gridding the area into 36 stations where surface radiometric pollution readings recorded and soil samples collected by using an auger for the top 30 Cm which represents the root zone of the area. Soil samples tested in the laboratory by using can technique with CR-39 type track detectors, while surface readings performed by using a portable Geiger counter device.  Soil surface readings and laboratory analysis results were processed by computer in order to draw contour maps which showed the variation of radon emission anomalies across the area. The aim behind this processing and interpretation is to provide an evaluation for the health environmental impact related to the radioactivity of the top soil and the area surface. The results of this study showed that radon emissions were below the standard limits and this makes it possible to invest the area for future human housing and other activities.

scholarly journals Quantification of Phytophthora capsici Oospores in Soil by Sieving-Centrifugation and Real-Time Polymerase Chain Reaction

Plant Disease ◽  
2008 ◽  
Vol 92 (1) ◽  
pp. 143-149 ◽  
Author(s):  
C. F. Pavón ◽  
M. Babadoost ◽  
K. N. Lambert
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
Sucrose Solution ◽  
Quantitative Polymerase Chain Reaction ◽  
Phytophthora Capsici ◽  
Soil Samples ◽  
Infested Soil ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
The Relationship

A procedure was developed to quantify Phytophthora capsici oospores in soil by combining a sieving-centrifugation method and a real-time quantitative polymerase chain reaction (QPCR) assay. Five soil samples representing three different soil textures were infested with oospores of P. capsici to produce 101, 102, 103, 104, or 105 spores per 10 g of air-dried soil. Each 10-g sample of infested soil was suspended in 400 ml of water and then passed through 106-, 63-, and 38-μm metal sieves. The filtrate was then passed through a 20-μm mesh filter. Materials caught on the filter were washed with water into two 50-ml centrifuge tubes and spun for 4 min (900 × g). The pellet was suspended in 30 ml of 1.6 M sucrose solution and centrifuged for 45 s (190 × g). The supernatant was passed through the 20-μm mesh filter. The sucrose extraction process of oospores was repeated five times to maximize oospore extraction. Materials caught on the 20-μm mesh filter were washed with water into a 50-ml tube and spun for 4 min (900 × g). The pellet was suspended in 1 ml of water, and the number of oospores was determined with a haemocytometer. The relationship between number of oospores recovered from the soil and number of oospores incorporated into the soil was Ŷ = –0.95 + 1.31X – 0.03X2 (R2 = 0.98), in which Ŷ = log10 of number of oospores recovered from the soil and X = log10 of number of oospores incorporated into the soil. The oospores were germinated after treatment with 0.1% KMnO4 solution for 10 min to induce germination. On the basis of the detection of ribosomal DNA, a QPCR method for P. capsici oospores was developed. PCR inhibitors were eliminated by extracting oospores from the soil by sieving-centrifugation. DNA was extracted and quantified from P. capsici oospores with suspensions of 101, 101.5, 102, 102.5, 103, 103.5, 104, 104.5, and 105 oospores per ml of water. The relationship between the DNA quantities and number of P. capsici oospores was Ŷ = –3.57 – 0.54X + 0.30X2 (R2 = 0.93), in which Ŷ = log10 (nanogram of P. capsici DNA) and X = log10 (number of oospores). The relationship between the quantity of DNA of P. capsici oospores recovered from the soil and the number of oospores incorporated into the soil was determined by Ŷ = –3.53 – 0.73X + 0.32X2 (R2 = 0.955, P < 0.05), in which Ŷ = log10 (DNA quantity of P. capsici oospores recovered from the soil) and X = log10 (number of P. capsici oospores incorporated into the soil). Utilizing the sieving-centrifugation and QPCR methods, oospores of P. capsici were quantified in soil samples collected from commercial fields.

Factors Affecting Seed Germination of Perennial Wall Rocket (Diplotaxis tenuifolia) in Southern Australia

Weed Science ◽  
2007 ◽  
Vol 55 (5) ◽  
pp. 481-485 ◽  
Author(s):  
Samuel G. L. Kleemann ◽  
Bhagirath S. Chauhan ◽  
Gurjeet S. Gill
Keyword(s):  
Osmotic Potential ◽  
Seedling Recruitment ◽  
Seedling Emergence ◽  
South Australia ◽  
Soil Surface ◽  
Burial Depth ◽  
Optimal Conditions ◽  
Factors Affecting ◽  
Depth Of Burial ◽  
Osmotic Potentials

Germination response of perennial wall rocket to temperature, light, osmotic potential, and depth of burial emergence was evaluated under controlled environmental conditions. The effect of seed burial depth on seedling recruitment in the field was also investigated at Roseworthy, South Australia. Under optimal conditions (30 C, light/dark) germination of perennial wall rocket was rapid, with 90% of seeds germinating within 48 h of imbibition. Germination was reduced (20%) at lower, suboptimal temperatures (10 to 20 C) when seeds of perennial wall rocket were exposed to light. Germination declined with increasing osmotic potential and was completely inhibited at osmotic potentials of −1.5 MPa. Perennial wall rocket emergence was greatest from seeds placed on the soil surface, but some seedlings (< 10%) emerged from a depth of 0.5 to 2 cm. Under both field and growth-cabinet conditions, the greatest seedling emergence of perennial wall rocket occurred from seed present on the soil surface; however, the level of absolute recruitment from the seed bank was much lower (< 5%). Information gained from this study will further improve our understanding of the germination behavior of perennial wall rocket and contribute to developing sustainable strategies for its control.

The responses of sorghum and sunflowers to 2,4-D and dicamba residues in clay soils in central Queensland

1992 ◽  
Vol 32 (2) ◽  
pp. 183 ◽  
Author(s):  
SR Walker ◽  
VA Osten ◽  
DW Lack ◽  
L Broom
Keyword(s):  
Seedling Growth ◽  
Dry Matter ◽  
Soil Surface ◽  
Growth And Yield ◽  
Clay Soils ◽  
Moist Soil ◽  
Sowing Depth ◽  
Field Environment ◽  
Dry Soil ◽  
Sorghum Bicolor L

The residual phytotoxicity of 2,4-D mine and dicamba to sorghum (Sorghum bicolor L.) and sunflowers (Helianthus annuus L.) was investigated under central Queensland conditions of variable rainfall and high temperatures. Effects of soil water content, sowing depth, and leaching in clay soils were determined. Phytotoxicity, as measured by decreases in shoot dry matter in pots, increased with herbicide rate and decreased rapidly in moist soil (34% w/w) but was maintained for at least 14 days in dry soil (114% w/w). 2,4-D and dicamba were phytotoxic when leached into the soil but not when they remained on the soil surface. Seedling growth and yield were not affected by 2 kg 2,4-Dha applied at 7 or more days pre-sowing, or by 0.5 kg 2,4-D/ha and 0.14 kg dicamba/ha applied at 1 day pre-sowing, in 5 field environments. When either herbicide was applied at higher rates 1 day pre-sowing, seedling growth was reduced if 25 mm of irrigation was received within 4 days of sowing, and yields were reduced in the field environment that received 144 mm of rainfall within 14 days of sowing.

scholarly journals Survival of Teliospores of Tilletia indica in Soil

Plant Disease ◽  
2004 ◽  
Vol 88 (1) ◽  
pp. 56-62 ◽  
Author(s):  
M. Babadoost ◽  
D. E. Mathre ◽  
R. H. Johnston ◽  
M. R. Bonde
Keyword(s):  
Soil Samples ◽  
Infested Soil ◽  
Silty Clay ◽  
Tilletia Indica ◽  
Teliospore Germination ◽  
Different Temperatures ◽  
Loam Soil ◽  
The Mean ◽  
Northern United States ◽  
Depth Of Burial

This study was conducted to assess survival of Tilletia indica teliospores in a location in the northern United States. Soils differing in texture and other characteristics were collected from four locations, equilibrated to -0.3 MPa, and infested with teliospores of T. indica to give a density of 103 teliospores per gram of dry soil. Samples (22 g) of the infested soil were placed in 20-μm mesh polyester bags, which were sealed and placed at 2-, 10-, and 25-cm depths in polyvinyl chloride tubes containing the same field soil as the infested bags. Tubes were buried vertically in the ground at Bozeman, MT, in October 1997. Soil samples were assayed for recovery and germination of T. indica teliospores 1 day and 8, 20, and 32 months after incorporation of teliospores into soil. The rates of teliospores recovered from soil samples were 90.2, 18.7, 16.1, and 13.3% after 1 day and 8, 20, and 32 months after incorporation of teliospores into soil, respectively, and was significantly (P < 0.01) affected by soil source. The percentage of teliospore recovery from soil was the greatest in loam soil and lowest from a silt loam soil. The rate of teliospores recovered from soil was not significantly affected by depth of burial and the soil source-depth interaction during the 32-month period. The percentage of germination of teliospores was significantly (P < 0.01) affected by soil source and depth of burial over the 32-month period. The mean percentage of teliospore germination at 1 day, and 8, 20, and 32 months after incorporation into soils was 51.3, 15.1, 16.4, and 16.5%, respectively. In another experiment, samples of silty clay loam soil with 5 × 103 teliospores of T. indica per gram of soil were stored at different temperatures in the laboratory. After 37 months of incubation at 22, 4, -5, and -18°C, the rates of teliospore recovered from soil were 1.6, 2.0, 5.7, and 11.3%, respectively. The percentage of spore germination from soil samples was highest at -5°C. Microscopy studies revealed that disintegration of teliospores begin after breakdown of the sheath-covering teliospore. The results of this study showed that teliospores of T. indica can survive in Montana for more than 32 months and remain viable.

Five Decades of Research Experience in Speech Anatomy and Physiology

2016 ◽  
Vol 1 (5) ◽  
pp. 4-12
Author(s):  
David P. Kuehn
Keyword(s):  
Ohio State University ◽  
State University ◽  
Research Experience ◽  
University Of Iowa ◽  
University Of Illinois ◽  
Anatomy And Physiology ◽  
The Ohio State University ◽  
Speech Science ◽  
The University ◽  
East Carolina University

This report highlights some of the major developments in the area of speech anatomy and physiology drawing from the author's own research experience during his years at the University of Iowa and the University of Illinois. He has benefited greatly from mentors including Professors James Curtis, Kenneth Moll, and Hughlett Morris at the University of Iowa and Professor Paul Lauterbur at the University of Illinois. Many colleagues have contributed to the author's work, especially Professors Jerald Moon at the University of Iowa, Bradley Sutton at the University of Illinois, Jamie Perry at East Carolina University, and Youkyung Bae at the Ohio State University. The strength of these researchers and their students bodes well for future advances in knowledge in this important area of speech science.

University Geographies and Folk Music Landscapes

2016 ◽  
Vol 33 (1) ◽  
pp. 92-116 ◽  
Author(s):  
David K. Blake
Keyword(s):  
Mass Culture ◽  
Folk Music ◽  
Traditional Music ◽  
Rural Landscape ◽  
Power Structures ◽  
Distant Object ◽  
University Of Illinois ◽  
Liberal Politics ◽  
Cultural Form ◽  
The University

By examining folk music activities connecting students and local musicians during the early 1960s at the University of Illinois at Urbana-Champaign, this article demonstrates how university geographies and musical landscapes influence musical activities in college towns. The geography of the University of Illinois, a rural Midwestern location with a mostly urban, middle-class student population, created an unusual combination of privileged students in a primarily working-class area. This combination of geography and landscape framed interactions between students and local musicians in Urbana-Champaign, stimulating and complicating the traversal of sociocultural differences through traditional music. Members of the University of Illinois Campus Folksong Club considered traditional music as a high cultural form distinct from mass-culture artists, aligning their interests with then-dominant scholarly approaches in folklore and film studies departments. Yet students also interrogated the impropriety of folksong presentation on campus, and community folksingers projected their own discomfort with students’ liberal politics. In hosting concerts by rural musicians such as Frank Proffitt and producing a record of local Urbana-Champaign folksingers called Green Fields of Illinois (1963), the folksong club attempted to suture these differences by highlighting the aesthetic, domestic, historical, and educational aspects of local folk music, while avoiding contemporary socioeconomic, commercial, and political concerns. This depoliticized conception of folk music bridged students and local folksingers, but also represented local music via a nineteenth-century rural landscape that converted contemporaneous lived practice into a temporally distant object of aesthetic study. Students’ study of folk music thus reinforced the power structures of university culture—but engaging local folksinging as an educational subject remained for them the most ethical solution for questioning, and potentially traversing, larger problems of inequality and difference.

The Early Years of the Jewish Presence at the University of Illinois

1992 ◽  
Vol 2 (2) ◽  
pp. 215-245
Author(s):  
Winton U. Solberg
Keyword(s):  
Higher Education ◽  
The United States ◽  
Early Years ◽  
Late Nineteenth Century ◽  
Characteristic Form ◽  
University Of Illinois ◽  
American Higher Education ◽  
Jewish Students ◽  
The University ◽  
The Church

For over two centuries, the College was the characteristic form of higher education in the United States, and the College was closely allied to the church in a predominantly Protestant land. The university became the characteristic form of American higher education starting in the late nineteenth Century, and universities long continued to reflect the nation's Protestant culture. By about 1900, however, Catholics and Jews began to enter universities in increasing numbers. What was the experience of Jewish students in these institutions, and how did authorities respond to their appearance? These questions will be addressed in this article by focusing on the Jewish presence at the University of Illinois in the early twentieth Century. Religion, like a red thread, is interwoven throughout the entire fabric of this story.

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