Abstract

PETEIRA, Belkis; TOLEDO, Verónica  and  MARTINEZ, B. MOLECULAR VARIABILITY IN Phytophthora nicotianae VAN BREDA DE HAAN ISOLATES. Rev. Protección Veg. [online]. 2008, vol.23, n.3, pp.183-190. ISSN 1010-2752.

The black shank, caused by the phytopathogen Phytophthora nicotianae is one of the fungal diseases in tobacco crop. To support, in a rational way, the breeding program for the obtaninig of resistant varieties in this crop, it is necessary to know about the variablity in the pathogen isolates. The molecular techniques are a useful tool in such way. By the ITS, the cutting of ITS amplified fragments and RAPDs, 50 representative isolates from different regions of the country, strains and cultural characters, were studied. ITS presents a common product 850bp for all the isolates and their digestion was possible only with the MspI enzyme. Two restriction patterns were obtained with 300 and 400bp, but non of them had a correlation with pathogenicity or geographic origin; however it is posible to use this technique for diagnostic porposes at species level. RAPDs analysis showed a high molecular variation between the isolates tested. The cluster from the molecular data did not correlate with the other characteristics selected.

Keywords : Phytophthora nicotianae; molecular characterization; RAPD; ITS.

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