Determination of Phytophthora Species Causing Root and Crown Rot on Tomatoes Grown in Antalya Province and Reactions of Some Tomato Genotypes against Phytophthora nicotianae

Antalya province is the main center of vegetable production in Türkiye. Tomato comes first in terms of crops cultivated under greenhouse. Phytophthora species causing root and crown rot are among the factors negatively affecting tomato yield and quality. This research aimed to determine the prevalence of root and crown rot of tomatoes grown in Antalya province and to identify Phytophthora species causing disease. During surveys performed in 170 tomato greenhouses, plant and soil samples were taken from the areas where root and crown rot, stem blight, and drying symptoms were observed. Disease prevalence and incidence in the investigated greenhouses were 25.88% and 4.87%, respectively. Phytophthora symptoms were not observed in the greenhouses in Demre and Kepez districts, while the highest disease prevalence was found in Elmalı district with 75%. Eighty of 84 Phytophthora isolates were identified as P. nicotianae and four as P. capsici, according to their cultural, morphological and molecular characterisation. Virulence of 18 selected isolates were determined by using stem inoculation technique and all isolates caused lesions with different lengths on tomato stems. The reactions of 22 tomato genotypes in the gene pool of BATEM against P. nicotianae were also investigated and the genotype DT-15 was found as the most susceptible genotype with the largest lesions, while A-286 was the most resistant genotype. This study formed the basis for further studies on tomato breeding and integrated disease management.