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Models And Applications For Risk Assessment And Prediction Of Asian Soybean Rust Epidemics, Emerson M. Del Ponte, Cláudia V. Godoy, Marcelo G. Canteri, Erlei M. Reis, X. B. Yang Nov 2006

Models And Applications For Risk Assessment And Prediction Of Asian Soybean Rust Epidemics, Emerson M. Del Ponte, Cláudia V. Godoy, Marcelo G. Canteri, Erlei M. Reis, X. B. Yang

Plant Pathology and Microbiology Publications

Asian rust of soybean [Glycine max (L.) Merril] is one of the most important fungal diseases of this crop worldwide. The recent introduction of Phakopsora pachyrhiziSyd. & P. Syd in the Americas represents a major threat to soybean production in the main growing regions, and significant losses have already been reported. P. pachyrhizi is extremely aggressive under favorable weather conditions, causing rapid plant defoliation. Epidemiological studies, under both controlled and natural environmental conditions, have been done for several decades with the aim of elucidating factors that affect the disease cycle as a basis for disease modeling. The recent spread of ...


Trans Regulation Of Cap-Independent Translation By A Viral Subgenomic Rna, Ruizhong Shen, Aurélie Mamisoa Rakotondrafara, W. Allen Miller Oct 2006

Trans Regulation Of Cap-Independent Translation By A Viral Subgenomic Rna, Ruizhong Shen, Aurélie Mamisoa Rakotondrafara, W. Allen Miller

Plant Pathology and Microbiology Publications

Many positive-strand RNA viruses generate 3′-coterminal subgenomic mRNAs to allow translation of 5′-distal open reading frames. It is unclear how viral genomic and subgenomic mRNAs compete with each other for the cellular translation machinery. Translation of the uncapped Barley yellow dwarf virus genomic RNA (gRNA) and subgenomic RNAI (sgRNAI) is driven by the powerful cap-independent translation element (BTE) in their 3′ untranslated regions (UTRs). The BTE forms a kissing stem-loop interaction with the 5′ UTR to mediate translation initiation at the 5′ end. Here, using reporter mRNAs that mimic gRNA and SgRNA1, we show that the abundant sgRNA2 ...


Soybean Stem Colonization By Genotypes A And B Of Cadophora Gregata Increases With Increasing Population Densities Of Heterodera Glycines, G. M. Tabor, G. L. Tylka, C. R. Bronson Oct 2006

Soybean Stem Colonization By Genotypes A And B Of Cadophora Gregata Increases With Increasing Population Densities Of Heterodera Glycines, G. M. Tabor, G. L. Tylka, C. R. Bronson

Plant Pathology and Microbiology Publications

Growth chamber experiments were conducted to investigate whether parasitism by increasing population densities of Heterodera glycines, the soybean cyst nematode, increases the incidence and severity of stem colonization by the aggressive genotype A and the mild genotype B of Cadophora gregata (Phialophora gregata), causal agents of brown stem rot of soybeans. Soybean genotypes with three combinations of resistance and susceptibility to H. glycines and genotype A of C. gregata were inoculated with each genotype of C. gregata alone or each genotype with two population densities of H. glycineseggs, 1,500 or 10,000 per 100 cm3 of soil ...


A New Greenhouse Method To Assay Soybean Resistance To Brown Stem Rot, G. A. Tabor, S. R. Cianzio, G. L. Tylka, R. Roorda, C. R. Bronson Sep 2006

A New Greenhouse Method To Assay Soybean Resistance To Brown Stem Rot, G. A. Tabor, S. R. Cianzio, G. L. Tylka, R. Roorda, C. R. Bronson

Plant Pathology and Microbiology Publications

Greenhouse, growth chamber, and field experiments were conducted to develop a method to assess resistance of soybeans to Cadophora gregata (Phialophora gregata), causal agent of brown stem rot (BSR). In the new method, C. gregata is introduced at the base of the stems of 2-week-old soybeans, and the presence of the fungus is assessed in the tips of the stems 5 weeks later. To test the effectiveness of the method, two populations of soybeans and 10 checks were inoculated at the stem base and then assayed for fungal colonization of the stem tips, percentage of symptomatic leaflets, and percent internal ...


A Root-Knot Nematode Secretory Peptide Functions As A Ligand For A Plant Transcription Factor, Guozhong Huang, Ruihua Dong, Rex Allen, Eric L. Davis, Thomas J. Baum, Richard S. Hussey May 2006

A Root-Knot Nematode Secretory Peptide Functions As A Ligand For A Plant Transcription Factor, Guozhong Huang, Ruihua Dong, Rex Allen, Eric L. Davis, Thomas J. Baum, Richard S. Hussey

Plant Pathology and Microbiology Publications

Parasitism genes expressed in the esophageal gland cells of root-knot nematodes encode proteins that are secreted into host root cells to transform the recipient cells into enlarged multinucleate feeding cells called giant-cells. Expression of a root-knot nematode parasitism gene which encodes a novel 13-amino-acid secretory peptide in plant tissues stimulated root growth. Two SCARECROW-like transcription factors of the GRAS protein family were identified as the putative targets for this bioactive nematode peptide in yeast two-hybrid analyses and confirmed by in vitro and in vivo coimmunoprecipitations. This discovery is the first demonstration of a direct interaction of a nematode-secreted parasitism peptide ...


Quantifying The Feeding Periods Required By Corn Flea Beetles To Acquire And Transmit Pantoea Stewartii, B. Menelas, Charles C. Block, Paul Esker, Forrest W. Nutter Jr. Mar 2006

Quantifying The Feeding Periods Required By Corn Flea Beetles To Acquire And Transmit Pantoea Stewartii, B. Menelas, Charles C. Block, Paul Esker, Forrest W. Nutter Jr.

Plant Pathology and Microbiology Publications

The feeding periods required by corn flea beetles to acquire and transmit Pantoea stewartii were investigated in the Stewart's disease of corn pathosystem. To quantify the effect of acquisition feeding period on percentage of acquisition, field-collected corn beetles were allowed to feed for 6, 12, 24 36, 48, and 72 h on corn seedlings previously inoculated with a rifampicin- and nalidixic acid-restraint strain of P. stewartii. Acquisition of P. stewartii by corn flea beetles was considered positive if the rifampicin- and nalidixic acid-marked strain was recovered on selective media. To quantity the effect of transmission feeding period on percent ...


Assessing Heterodera Glycines-Resistant And Susceptible Cultivar Yield Response, P. A. Donald, P. E. Pierson, S. K. St. Martin, P. R. Sellers, G. R. Noel, A. E. Macguidwin, J. Faghihi, V. R. Ferris, C. R. Grau, D. J. Jardine, H. Melakeberhan, T. L. Niblack, W. C. Stienstra, G. L. Tylka, T. A. Wheeler, D. S. Wysong Mar 2006

Assessing Heterodera Glycines-Resistant And Susceptible Cultivar Yield Response, P. A. Donald, P. E. Pierson, S. K. St. Martin, P. R. Sellers, G. R. Noel, A. E. Macguidwin, J. Faghihi, V. R. Ferris, C. R. Grau, D. J. Jardine, H. Melakeberhan, T. L. Niblack, W. C. Stienstra, G. L. Tylka, T. A. Wheeler, D. S. Wysong

Plant Pathology and Microbiology Publications

The soybean cyst nematode Heterodera glycines (SCN) is of major economic importance and widely distributed throughout soybean production regions of the United States where different maturity groups with the same sources of SCN resistance are grown. The objective of this study was to assess SCN-resistant and -susceptible soybean yield responses in infested soils across the northcentral region. In 1994 and 1995, eight SCN-resistant and eight SCN-susceptible public soybean cultivars representing maturity groups (MG) I to IV were planted in 63 fields, either infested or noninfested, in 10 states in the north-central United States. Soil samples were taken to determine initial ...


Studies On Seed Colouring In Soybean And Tomato, Vilas A. Tonapi, P. Harinath Babu, S. Varanavasiappan, Ch Ravinder Reddy, Shrishail S. Navi, N. Seetharama Jan 2006

Studies On Seed Colouring In Soybean And Tomato, Vilas A. Tonapi, P. Harinath Babu, S. Varanavasiappan, Ch Ravinder Reddy, Shrishail S. Navi, N. Seetharama

Plant Pathology and Microbiology Publications

The effects of seed colouring using 25 dyes (i.e. 20 chemical and 5 natural dyes) on the quality of soyabean (cv. JS 335) and tomato (cv. Pusa Ruby) seeds were studied in the laboratory. Data were recorded for seed germination percentage, root and shoot length, whole seedling length, dry weight of seedling, vigour index, speed of germination and electrical conductivity. Rhodamine-B, Fast green and Malachite green for soyabean and Rhodamine-B and Fast green for tomato were the best dyes for seed colouring.


Management Of Urd Bean Leaf Crinkle Virus In Urd Bean (Vigna Mungo L. Hepper), Ch Ravinder Reddy, Vilas A. Tonapi, S. Varanavasiappan, Shrishail S. Navi, R. Jarayajan Jan 2006

Management Of Urd Bean Leaf Crinkle Virus In Urd Bean (Vigna Mungo L. Hepper), Ch Ravinder Reddy, Vilas A. Tonapi, S. Varanavasiappan, Shrishail S. Navi, R. Jarayajan

Plant Pathology and Microbiology Publications

Six plant extracts viz , Mirabtlis jalapa, Carthamus roseus. Datura metal, Bougainvitlea spectabilis, Boerhaavia diffusa and Azadirachta indica recorded maximum reduction in the incidence of urd bean leaf crinkle virus (ULCV) in urd bean crops at field level Among the antiphytovirat chemicals tested, DHT reduced the transmission to the maximum extent and increased the incubation period of virus in the urd bean plant Fresh buttermilk was significantly superior to fermented buttermilk in reducing the disease spread and increasing the incubation period of the virus in the plant. Casein was found effective in reducing the per cent transmission and increased the incubation ...


Oscillating Kissing Stem-Loop Interactions Mediate 5′ Scanning-Dependent Translation By A Viral 3′-Cap-Independent Translation Element, Aurélie Mamisoa Rakotondrafara, Charlotta Polacek, Eva Harris, W. Allen Miller Jan 2006

Oscillating Kissing Stem-Loop Interactions Mediate 5′ Scanning-Dependent Translation By A Viral 3′-Cap-Independent Translation Element, Aurélie Mamisoa Rakotondrafara, Charlotta Polacek, Eva Harris, W. Allen Miller

Plant Pathology and Microbiology Publications

The 3′-untranslated regions (UTRs) of a group of novel uncapped viral RNAs allow efficient translation initiation at the 5′-proximal AUG. A well-characterized model is the Barley yellow dwarf virus class of cap-independent translation elements (BTE). It facilitates translation by forming kissing stem-loops between the BTE in the 3′-UTR and a BTE-complementary loop in the 5′-UTR. Here we investigate the mechanisms of the long-distance interaction and ribosome entry on the RNA. Upstream AUGs or 5′-extensions of the 5′-UTR inhibit translation, indicating that, unlike internal ribosome entry sites in many viral RNAs, the BTE relies on ...


Effect Of Environmental Factors During Seed Development And Maturation On Seed Quality In Sorghum Bicolor (L.) Moench, Vilas A. Tonapi, S. Varanavasiappan, Shrishail S. Navi, Ch Ravinder Reddy, T. V. Karivatharaju Jan 2006

Effect Of Environmental Factors During Seed Development And Maturation On Seed Quality In Sorghum Bicolor (L.) Moench, Vilas A. Tonapi, S. Varanavasiappan, Shrishail S. Navi, Ch Ravinder Reddy, T. V. Karivatharaju

Plant Pathology and Microbiology Publications

Studies were conducted to evaluate the effect of environmental conditions on physiological characteristics of seeds of sorghum genotypes viz., CO 24, CO 25, CO 26 and JH 35 during seed development and maturation. In the present study, a steady decline in moisture content of the seed was observed. Length and width of seed increased rapidly between seven to 35 days after 50 per cent flowering. A steep increase in the dry weight of seed was registered between 14 and 35 days after 50 per cent flowering, beyond that the increase was gradual. Water absorption per cent declined from 16.5 ...