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J A Verreet

Publications and source records attributed to J A Verreet.

5 recordsLinked to original sources
PubMed2006

Differences between the fingerprints generated from total RNA and poly-A RNA using a modified procedure of cDNA-AFLP and silver staining.

A modified procedure of cDNA-amplified fragment length polymorphism (cDNA-AFLP) combined with silver staining is described which generates clear band patterns from both fungal total RNA and poly-A RNA. The silver staining procedure takes only 25 min. Some 42-55 transcript-derived fragments (TDFs) were yielded from the total RNA of eight fungal pathogens. In comparison with the fingerprints generated from Mycosphaerella graminicola total RNA, those from poly-A RNA showed eight TDFs with an increased intensity and also seven additional TDFs. It suggests that poly-A RNA is preferable as starting material for ideal cDNA-AFLP analysis.

Comet Assay↗
PubMed2005

Rapid and efficient extraction of genomic DNA from different phytopathogenic fungi using DNAzol reagent.

A modified procedure using the commercial DNAzol reagent was successfully applied to extract genomic DNA from 25 fungal species. The DNA yield varied from 306 to 1,927 microg g(-1) dry mycelia and the A(260)/A(280) ratio from 1.59 to 1.93. Compared with the method of J.L. Cenis (Nucleic Acids Res. 1992, 20: 2380) this procedure generated a higher DNA yield from 17 species and a higher A(260)/A(280) ratio from 23 species. But for four species, Cenis (1992) method was more suitable. No inhibitor of polymerase chain reaction was evident for the DNA extracted by the modified procedure, whereas some inhibitors remained in DNA of eight species extracted by the previous method.

Base Sequence↗
PubMed2003

The IPM Wheat Model--results of a three-year study in North Rhine-Westphalia, Lower Saxony and Schleswig-Holstein.

Under the primary utilisation of phytosanitary production factors such as selection of variety, crop rotation and N fertilisation according to plant requirements, the IPM Wheat Model comprises the elements diagnosis (qualitative = type of pathogen, quantitative = disease severity), scientifically grounded treatment thresholds which, as critical values in pathogen development, can be applied to define the optimum time of fungicide application, and pathogen-specific effective fungicides and application amounts. This leads to the location and year-specific optimised control of the pathogen and of the associated yield performance. After several years of development in Bavaria (from 1985 on) and Schleswig-Holstein (1993-1999), the model was tested as part of a project involving the Universities of Bonn and Kiel and the plant protection services of the German states of Lower Saxony, North Rhine-Westphalia and Schleswig-Holstein in a three-year study (1999-2001) in interregional locations (usually nine per state) with the winter wheat variety Ritmo (interregional indicator variety) and a further variety of regional importance in different variations (untreated control, three to four times growth stage-oriented variants for the determination of the absolute damage potential, IPM-variant). In exact records (approx. 12 dates per vegetation period), the disease epidemics were recorded weekly. With the genetically uniform indicator variety Ritmo, the results documented substantially differing year- and location-specific disease and yield patterns. Interregionally, a broad wheat pathogen spectrum (Puccinia striiformis, P. recondita, Septoria tritici, Stagonospora (syn. Septoria) nodorum, Blumeria (syn. Erysiphe) graminis, Pseudocercosporella herpotrichoides, Drechslera tritici-repentis) in differing composition, disease severity and damage effect was demonstrated. The heterogeneity of the infection and damage patterns was increased in the case of the second variety, in association with the genetic variability. The epidemiologically-orientated indications (average two, reduced application amounts) according to the IPM Wheat Model in association with time-diverging progressions led, on an interregional basis, with minimum input and in association with the diverging dynamics, to a biologically and economically optimised fungicide application. In the context of economic and ecological performance, the comprehensive results of the project demonstrated the valuable functionality of the IPM Wheat Model.

Dose-Response Relationship, Drug↗
PubMed2002

Evaluation of the IPM Wheat Model in the Rhineland 2001.

The results of field trials at nine locations with two wheat cultivars in each case demonstrated the practicability of the action threshold-based fungicide strategy of the IPM Wheat Model under the intensive wheat production conditions in the Rhineland. Action thresholds used and dosage of fungicides applied are outlined. Despite using reduced rates of fungicides the epidemic development of relevant pathogens--mainly Septoria tritici and Puccinia recondita--was controlled in early stages of disease development. In plots treated according to the IPM Wheat Model disease incidence and disease severity were reduced effectively compared to untreated plots with low and high disease incidence, respectively. The effective control of pathogens using pathogen-specific action thresholds resulted in yield levels very similar to those of disease-free plots simultaneously minimising the total amount of fungicides applied. Disease control according to the IPM Wheat Model raised yields by up to 25% with monetary benefits averaging more than [symbol: see text] 100 ha-1 in 2001.

Fungi↗