Ethiological studies of root rot of parsnip (Pastinaca sativa L.) in Vojvodina

Abstract

In the past few years, the symptoms of parsnip root rot (Pastinaca sativa L.) have been more intense in production. This had a significant impact on the decrease in the yield as well as the market value of the roots. Symptoms of rot are only noticed during harvest. Continued development of the pathogen has been reported in storage rooms, especially if the root is stored under uncontrolled conditions of temperature and humidity. The aim of the study was the etiological study of root rot in the open field and in storage rooms. Total of 56 root samples were collected in the period 2016 – 2019 years. Isolation was performed by standard of phytopathology procedure on PDA medium for fungi, MPA and CVP for bacteria. After growth, a collection of isolates was formed, which was included in the pathogenicity test. For the isolates that showed pathogenicity, the identification was performed, the fungi were identified on the basis of morphological characteristics, while the bacteria were studied for biochemical - physiological characteristics. Of the 42 fungus and bacterial isolates collected, 37 caused similar symptoms of rot, on artificially inoculated parsnip root, which was considered a pathogenic trait. Fusarium spp. was isolated from the symptoms of dry rot on the leaf rosette crossing, while Pectobacterium carotovorum subp. was isolated from the wet rot. The symptom of rot, followed by the white mycelium of the fungus, was preliminary indicated by the species Sclerotinia sclerotiorum, which was confirmed by isolation and identification. The dominant species in storage rooms which provide root rot were Botrytis cinerea and Sclerotinia sclerotiorum. They were followed by Rhisopus spp. and Penicillium spp. species, but they have not been proven pathogenic and have been considered saprophytes. Root rot caused damage during harvest, as insects too, which allowed pathogens and saprophytes to penetrate.