Morphological characterization and genetic analysis of Drechslera teres isolates

Abstract

Net blotch, caused by the phytopathogen Drechslera teres, is a common disease of barley (Hordeum vulgare L) and is responsible for large economic losses in some barley growing areas. In this study the morphology and genetic variability of eight D. teres isolates from different regions of the Brazilian state of Rio Grande do Sul were investigated. Colony morphology was studied on potato-dextrose-agar (PDA) and genetic variability investigated using the random amplified polymorphic-DNA (RAPD) technique. 27 commercially available primers were tested of which 16 were selected for use in polymorphic analysis due to their good resolution and reproducibility. Similarity coefficients were used to construct dendrograms based on colony morphology and RAPD data showing the relationship between the eight isolates studied. Colony morphology showed variability between the isolates while RAPD assays showed high similarity coefficients, but grouping of the isolates according to the geographic origins of the seeds from which they were isolated was not possible.

In Vitro Morphological Characteristics of Pyrenophora tritici-repentis Isolates from Several Algerian Agro-Ecological Zones

“…Dos Santos et al (2002) studied P. tritici-repentis , McDonald (1967) and Frazzon et al (2002) studied Pyrenophora teres isolates, and observed significant morophological variation based on mycelial colony colors. Similar results were reported by Benslimane (2002) and Christensen and Graham (1934) when they studied Pyrenophora graminea isolates for their morphological variation.…”

Genetic variability ofPhytophthora sojaeisolates from Argentina

“…This method uses primers of arbitrary sequence, which allows an extensive random sampling of the genome. For this reason RAPD has been used to detect genetic variation at the species level (McDermont et al 1994, Gosselin et al 1996, Frazzon et al 2002, Doherty et al 2003, Silva et al 2003, Gouveia et al 2005, Zhou et al 2005.…”

Virulence of Icelandic Pyrenophora teres f. teres populations and resistance of Icelandic spring barley lines

“…Plant pathogens reproduce asexually or sexually, the latter form of reproduction leads often to a higher genetic variability (Goodwin et al 1992). Genetic variation in Ptt populations has been reported to be generally high (Jonsson et al 2000;Leisová et al 2005;Peltonen et al 1996;Rau et al 2003;Serenius et al 2005), with lower levels reported in Brazil (Frazzon et al 2002). For Ptt to produce the sexual stage and overwinter in order to spread in the subsequent growing season, the fungus requires barley stubble.…”