ISOLATION AND CHARACTERIZATION OF FUSARIUM OXYSPORUM F.SP. VASINFECTUM CAUSATIVE AGENT OF COTTON WILT DISEASE IN PUNJAB, PAKISTAN.

Fusarium cotton wilt (FW) is one of the most economically devastating cotton diseases worldwide and the threatening agent of this disease is Fusarium oxysporum f.sp. vasinfectum (FOV). This study aimed to add more information towards the isolation and identification of F. oxysporum f. sp. vasinfectum (FOV), which could probably be responsible for the wilting of their corresponding host, Gossypium hirsutum. Roots samples were collected from plants showing typical symptoms of wilting from three different regions (Kasur, Faisalabad, Multan) of province Punjab, Pakistan. For further analysis, samples were immediately transported to the microbiology laboratory of Government College University Faisalabad, Pakistan (GCUF). After surface sterilization of root, each cut piece (5 mm) of the root was inoculated on Potato Dextrose Agar (PDA) media and incubated at 25°C±2 °C for 7 days. The different obtained co1lonies were identified using the standard microbiological techniques such as macro-morphological, microscopic, and Polymerase Chain Reaction (PCR). The pathogenicity test was also performed in the greenhouse for confirmation of Koch's postulate. This test showed that plants infected with FOV start wilting and yellowing of leaves which confirmed that FOV was linked with cotton wilt and responsible for significant economic loss. Good agricultural practices and proper management of FOV will permit the production of healthy seedlings and subsequently aid in the improvement in cotton yield. [ABSTRACT FROM AUTHOR]