Fusarium incarnatum Causing Fusarium Wilt on Protea (Protea cynaroides L.) in Turkey

Abstract

Protea (Protea cynaroides L.) is one of the most important ornamental plants commercially cultivated in Turkey and other parts of the world. In May 2017, protea plants heavily showed wilting symptoms were obtained from the protea growing areas at Hatay province of Turkey. Brown vascular tissue in the stems of the infected plants was observed. To determine the causal agent of the disease, necrotic tissue pieces taken from diseased plants were surface-sterilized with 10% sodium hypochlorite, two times rinsed with sterile distilled water, placed on Petri dishes containing potato dextrose agar (PDA), and incubated at 24 oC for seven days. Microconidia were no septate, ovoid, hyaline, single-celled, and 9 to 12 × 1 to 3 μm. Macroconidia were slightly curved, four to six septate, and 27 to 31 × 3 to 5 μm. Based on the morphology and cultural features, the fungus was identified as F. incarnatum, which belongs to the F. incarnatum-equiseti species complex (FIESC). In addition, a pathogenicity test was made using the apple fruits. The pathogen was re-isolated from inoculated apple fruits and both cultural and morphological characteristics of the pathogen were identical. To confirm the identity of one representative isolate, the internal transcribed spacer (ITS) region including 5.8S rDNA was amplified and sequenced with primers of ITS-1 and ITS-4. Fusarium MLST, Fusarium-ID and GenBank database were used for the identification of sequence. The amplified 465 bp product has 99% nucleotide identity with the sequences of F. incarnatum-equiseti species complex of MLST types and deposited in GenBank under accession number (MH005097). According to the literature, this is the first molecular identification of F. incarnatum on protea plants in Turkey.