Mohammad Jawhar

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The fungus Cochliobolus sativus is the causal agent of barley common root rot disease. Twenty-two isolates of diverse geographical origin within Syria were studied in relation to pathogenicity, analysis of genomic DNA through random amplified polymorphic DNA (RAPD) and variation within the nuclear rDNA [internal transcribed spacers (ITS)]. The data(More)
Spot blotch caused by Cochliobolus sativus has been the major yield-reducing factor for barley production during the last decade. In this study, a systematic sequencing of expressed sequence tags (EST) was chosen to obtain a global picture of the assembly of genes involved in pathogenesis. To identify a large number of plant EST, which are induced at(More)
The fungus Cochliobolus sativus has been shown to be an efficient producer of xylanase from an industrial point of view. The addition of extra carbon sources and the initial moisture content of the solid-state fermentation were found to have a marked influence on the xylanase production by C. sativus Cs6 strain. Xylan and starch resulted in an increased(More)
Common root rot caused by Cochliobolus sativus, is an economically important disease found worldwide. In in vitro studies, the influence of salt on the growth and pathogenicity of C. sativus was investigated using potato dextrose agar adjusted to different osmotic potentials with NaCl and KCl. Mycelial growth rates, colony diameter and germination decreased(More)
Xylanase and amylase have gained increasing interest because of their various biotechnology applications. In this research, the restriction of PCR-amplified internal transcribed spacers (ITS) of ribosomal DNA (rDNA) was used to confirm the genetic variation among 22 isolates of Pyrenophora graminea differing in their xylanase and amylase production. The(More)
Spot blotch, caused by Cochliobolus sativus, is a common foliar disease of barley that is controlled primarily through the development of resistant cultivars. An assay involving the inoculation of a detached first leaf (DFL) maintained in vitro was used to determine the reaction of five barley genotypes to the disease. The estimation of the infected leaf(More)
Leaf scald caused by the infection of Rhynchosporium secalis, is a worldwide crop disease resulting in significant loss of barley yield. In this study, a systematic sequencing of expressed sequence tags (ESTs) was chosen to obtain a global picture of the assembly of genes involved in pathogenesis. To identify a large number of plant ESTs, which are induced(More)
Field research was undertaken to investigate the effects of potassium K2SO4 (36% K) as a foliar spray and/or soil application on grain yield, 1000-grain weight and severity of Septoria tritici blotch on wheat during 1998 and 1999. Two Syrian bread wheat cultivais (Bohuth 6 and Cham 6) and one promising mutant line (L92-6) were used in this study. Six(More)
The inter-retrotransposon amplified polymorphism (IRAP) was used to confirm the genetic variation among 22 strains of Pyrenophora graminea differing in their xylanase production. A total of 162 bands were scored of which 151 (93.21%) were polymorphic. The molecular parameter used showed that P. graminea strains reside in four phylogenetic groups. There was(More)
Systemic movement of Pyrenophora graminea in five barley genotypes was used to quantify the infection level of leaf stripe disease. The systemic movement of the fungus was slower in the resistant than in the susceptible genotypes and enabled easy differentiation among them. Significant correlations were found (P = 0.001) between relative in vitro value and(More)