in the present study, vegetative compatibility groups (vcg) of 27 isolates of fusarium solani collected from root and  crown of sugar beets of different provinces in iran were determined using nitrate non– utilizing (nit) mutants. totally, 222 nit mutants were generated from 27 isolates using pdc medium. based on the weak growth on basal medium containing one of four nitrogen sources the phenot...

glomerella cingulata is the causal agent of anthracnose disease on citrus that attacks weakened trees. the sexual stage is rare in nature but can be produced in laboratory under certain conditions. sixty-seven single-spore isolates were selected from citrus in mazandaran province to be used in this study. isolates were cultured on ypss for investigating heterothallism and homothallism. to under...

fusarium solain is the most important pathogen of huge range of plant hosts, especially potato in the word, which causes tuber rot in storage and root rot of potato plants in fields. fifty four isolates from potato, bean, chickpea and cucurbit (melon, watermelon and cucumber) was subjected in a study through analysis of vegetative compatibility groups (vcgs) and rep-pcr dna fingerprinting. nit ...

Colletotrichum lindemuthianum, the causative agent of bean anthracnose, is one of the most common pathogens leading to expressive damage to plants beyond presenting noticeable variability. The knowledge on vegetative compatibility groups (VCGs) is of particular interest in asexual fungi as they subdivide the population in groups that can exchange genetic information via heterokaryosis and the p...

Forty isolates of Fusarium verticillioides were recovered from corn seeds using Nash & Snyder media. Seed samples had been collected from the major producing area in Khuzestan and Ardabil provinces. Isolates were tested for their pathogenicity on the corn-detached stalks. Results revealed that all isolates were pathogenic to the plant samples tested. Four hundred and twenty nitrate non-utilizin...

forty monoconidial isolates of magnaporthe grisea were examined, for an identification of vegetative compatibility group and a characterization of genetic diversity, using rep-pcr genomic fingerprinting. the isolates were collected from weeds digitaria sanguinalis (crabgrass), setaria italica (foxtail millet), echinochloa crus-galli (barnyard millet), and some other unknown ones during 2003 - 2...

S. typhimurium nit mutants are defective in nitrogen assimilation, despite having normal levels of assimilatory enzymes. Complementation, enzyme assays, and genetic mapping show that nit is nadE. We present evidence that ammonia, not glutamine, is the physiological substrate for eubacterial NAD synthetases and that low activity completely accounts for the mutant phenotype.

Synthesis of wild-type Neurospora crassa assimilatory nitrate reductase is induced in the presence of nitrate ions and repressed in the presence of ammonium ions. Effects of several Neurospora mutations on the regulation of this enzyme are shown: (i) the mutants, nit-1 and nit-3, involving separate lesions, lack reduced nicotinamide adenine dinucleotide (NADPH)-nitrate reductase activity and at...

thirty five monoconidial isolates of the fungal culture collection pyricularia grisea were examined, to identify the vegetative compatibility groups and characterize the genetic diversity of isolates as through rep-pcr genomic fingerprinting. the isolates were collected from ricefields during 1997-1999. genetic diversity of p. grisea isolates was studied as based on dna fingerprinting through r...

Chlamydomonas is a popular genetic model system for studying many cellular processes. In this report, we describe a new approach to isolate Chlamydomonas genes using the cloned nitrate reductase gene (NIT1) as an insertional mutagen. A linearized plasmid containing the NIT1 gene was introduced into nit1 mutant cells by glass-bead transformation. Of 3000 Nit+ transformants examined, 74 showed mo...