Fusarium oxysporum as causal agent of tomato wilt and fruit rot

Abstract

Tomatoes are parasitized by a number of pathogens, including Fusarium oxysporum f. sp. lycopersici, causal agent of fusarium wilt. Fresh vegetable fruits can be contaminated with various fungi that produce mycotoxins, which is an important issue for human health. The objective of this paper was to isolate, determine, and identify causal organisms of tomato wilt and fruit rot, based on the pathogens morphological and molecular characteristics. Samples of diseased plants showing symptoms of tomato wilt were collected from different localities in the production region of Vojvodina. Fruits with symptoms of fusarium rot were collected from storage and warehouses. The isolation and morphological determination of the fungus were performed on PDA and Czapek's nutrient media. Isolates from diseased plants growing in field, designated as TFW1-TFW12 and seven isolates from diseased tomato fruits (TFM1-TFM7) were chosen for further investigation. For identification of the fungal isolates, the polymerase chain reaction (PCR) was also used. The EF1/EF2 primer pair was used for molecular identification of Fusarium sp. Nine analyzed samples were found to contain DNA fragments 700 bp in size.

Patogene gljive roda Fusarium, prouzrokovači uvenuća biljaka, pojavljuju se i kao paraziti povrća uzrokujući propadanje korena, prizemnog dela stabla, kao i uvenuće biljaka. Veći broj patogena parazitira paradajz, među kojima je i Fusarium oxysporum f. sp. Lycopersici, prouzrokovač fuzarioznog uvenuća. Fuzariozna trulež plodova paradajza redovno se javlja u skladištima i može naneti velike ekonomske gubitke. Cilj ovog rada bio je izolacija, utvrđivanje i identifikacija prouzrokovača uvenuća paradajza i truleži plodova, na osnovu morfoloških i molekularnih karakteristika patogena. Prikupljeni su uzorci obolelih biljaka sa simptomima uvenuća paradajza iz proizvodnih regiona Vojvodine. Sveži plodovi sa simptomima fuzariozne truleži prikupljeni su iz različitih magacina i skladišta. Za izolaciju i morfološku determinaciju gljive korišćene su PDA i Czapek hranljiva podloga. Za dalja proučavanja odabrano je 12 izolata (TFW1-TFW12) poreklom sa biljaka gajenih u polju i sedam izolata (TFM1-TFM7) dobijenih sa zaraženih plodova iz skladišta. Determinacija izolata gljiva obavljena je i pomoću metode, lančane reakcije polimeraze (PCR - Polymerase Chain Reaction). Za molekularnu identifikaciju izolata F. oxysporum korišćen je par prajmera EF1/EF2. U devet ispitivanih uzoraka potvrđeno je prisustvo DNK fragmenta veličine 700 bp.