1,720,978 research outputs found
Diaporthe helianthi isolate DCDSL 101/96 (IMI 318861) intergenic spacer region and 18S ribosomal RNA gene, partial sequence. autori Pecchia,S., Mercatelli,E. and Vannacci,G.
No full textSequenza AF51289
Diaporthe helianthi isolate DCDSL 2/96 (CBS 592.81) intergenic spacer region and 18S ribosomal RNA gene, partial sequence
No full textwww.ncbi.nlm.nih.go
Intraspecific variability in Diaporthe helianthi: study of sequences of the IGS region of ribosomal DNA
No full textDiaporthe helianthi isolate DCDSL 8/96 (F2) 28S large subunit ribosomal RNA gene, partial sequence
No full textSequenza AY31925
Amplificazione ed analisi RFLP dello spaziatore intergenico del DNA ribosomale in Pyrenophora graminea e P. teres
No full textDiaporthe helianthi isolate DCDSL 1/96 (A3) intergenic spacer region and 18S ribosomal RNA gene, partial sequence.
No full textSequenza AF51289
Variability of the IGS region as an indicator of relationships between three Pyrenophora species pathogenic on barley
No full textPCR amplification and characterization of the intergenic spacer region of the ribosomal DNA in Pyrenophora graminea
No full textSuccessful amplification of the whole intergenic spacer region of the nuclear ribosomal repeat (IGS) in Pyrenophora graminea was obtained with a PCR-based assay. Single amplification products showed length differences. Depending on the length of the IGS-PCR product, ca. 3.8 or 4.4 kb, two groups of isolates could be identified. The RFLP patterns of isolates obtained with the 6-base cutting enzymes ApaI, Bg/II, DraI, EcoRV, HindIII and SacI were similar within each group and different between the two groups. Restriction patterns of IGS-PCR products digested with the 4-base cutting enzyme AluI were polymorphic among isolates in spite of their IGS-PCR product length. In order to characterize the long and short IGS-PCR products the restriction map is shown. The long product shows an additional HindIII site and a Bg/II site that is lacking in the short product. However, the latter shows a SacI site that is not present in the long IGS-PCR product. Therefore: the described PCR-RFLP analysis of the IGS appears to be a useful tool to resolve genetic variation between P. graminea isolates. (C) 1998 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved
Intraspecific diversity within Diaporthe helianthi: evidence from rDNA intergenic spacer (IGS) sequence analysis
No full textDiaporthe helianthi is the causal agent of sunflower stem canker, a serious pathogen of sunflower in Europe but
recorded sporadically in Italy. The genetic diversity of D. helianthi isolates from different geographic origins
(Argentina, France, Italy, Yugoslavia, Romania) was investigated using IGS sequences. A 400 bp fragment of
the portion of the IGS region flanking the 5 end of the 18S gene was amplified from each isolate. The aligned
nucleotide sequences showed intraspecific sequence homology from 99–100% among French/Yugoslavian isolates
to 95–100% among Italian isolates. French/Yugoslavian isolates shared 90–92% sequence homology with Italian
isolates. The phylogenetic tree obtained from the aligned data revealed three separate groups. Group 1 included all
isolates from France and former Yugoslavia and one isolate from Argentina; Group 2 included all Italian isolates
and one isolate from Argentina. The most distantly related isolate was that from Romania (Group 3). The average
genetic distances among isolates within Group 1 and within Group 2 were 0.22 and 3.29 respectively. The analysis
showed that all isolates originating from countries where severe outbreaks of the disease are reported annually
(France and former Yugoslavia) form a well defined taxon characterized by relatively low variability. This group
is distinct from the group formed by isolates originating from Italy, whose variability is relatively much higher.
Results obtained revealed a marked differentiation among pathogen isolates, and members of Group 1 seem not
yet to have spread into Italian sunflower-growing areas
Diaporthe helianthi isolate DCDSL 778/00 (INRA 95100) intergenic spacer region and 18S ribosomal RNA gene, partial sequence
No full textwww.ncbi.nlm.nih.go
- …
