Salih Maden

Detection of Pathotypes and Genetic Diversity of Cercospora beticola

The pathotypes of Cercospora beticola, causal agent of sugar beet leaf spot disease, were identified by application of pathogenicity test using 100 isolates obtained from the provinces with intensive sugar beet cultivation. For the identification of pathotypes, five sugar beet cultivars were used each with different resistance factors. Cultivar reactions were determined by inoculation of cultivars with the isolates under controlled conditions and measuring disease severity on the 15 day according to the 1-9 KWS Scale. Based on the reactions of the five cultivars, a total of 15 pathotypes were detected. All employed sugar beet cultivars were resistant to Pathotype no:1 comprising most of the isolates. Genetic diversity of the causal agent was characterized by AFLP reaction. The products acquired at the end of AFLP reaction were detected by means of Beckman CEQ 8800 DNA Capillary Series Analysis and the results obtained were evaluated according to the similarity index UPGMA. For the genetic analysis of C. beticola isolates, 9874 polymorphic fragments of sizes between 100 and 500 bp were analysed which were generated by nine primers. The dendrogram derived from AFLP analysis depicted the existence of five different subgroups. The polymorphism rate among isolates was 91.13% and the dendrogram distribution of the pathotypes obtained by pathogenicity indicated that pathotypes were not discriminated and did not compose any groups.

Occurrence of Root Rot Caused by Phytophthora cryptogea on Common Sage (Salvia officinalis) in Turkey

Common sage or Dalmatian sage (Salvia officinalis L.) is a perennial plant (subshrub), native to the Mediterranean region. This research was conducted to identify the fungi species which cause a sudden damping-off disease in some common sage plantation, in the coastal experimental areas of Antalya and Izmir provinces of Turkey. The infected plant materials were collected from Mediterranean and Eagean regions which showed root and crown rots typical of Phytophthora sp. symptoms. Ten plants having those symptoms were used for identification of the causal agent by Phytophthora selective medium. A new Phytophthora species was isolated and identified as P. cryptogea as a result of morphological and molecular characteristics of DNA base sequences of internal transcribed spacer (ITS) regions. Pathogenicity of P. cryptogea was proved on rooted cuttings of common sage. This is the first report of P. cryptogea on common sage in Turkey.