Fusarium Wilt Identification and Root-Knot Nematode Effects on Commercial Cotton Cultivars In 2010

Fusarium wilt of cotton is a serious fungal disease caused by Fusarium oxysporum f. sp. vasinfectum (FOV) and highly impacted by root knot nematode (Meloidogyne incognita). Both pathogens are common in most cotton-producing areas and often inhabit the same fields. Root knot nematode (RKN) trial numbers were tested to determine their effect on cotton lines. Along with this, the identification of different FOV races from various cotton lines from ten commercial companies was studied. Cotton plants exhibiting wilt symptoms were collected; the fungi isolated, and spores from the isolation cultivated on Acidified Potato Dextrose Agar (APDA). DNA was extracted using two sets of primers. ITS1 and ITS4 primers amplified the internal transcribed spacer (ITS) region, and sequences from the translation elongation factor (EF-1α) helped characterize the isolates. Results indicate that the population of F. oxysporum f. sp. vasinfectum in the southeastern United States is more diverse than previously recognized and additional research to categorize and monitor the identity of FOV present in Alabama is needed.