Variability in Isolates of Fusarium oxysporum f. sp. carthami Causing Wilt of Safflower

Variability among eleven isolates of Fusarium oxysporum f sp. carthami Klisiewicz and Houston collected from different locations in three states viz., Andhra Pradesh, Karnataka and Maharashtra was studied in respect of cultural and morphological characters. Six Fusarium isolates produced fluffy white mycelium while five isolates produced cottony white mycelium on Potato dextrose agar (PDA) medium. The colony diameter of 11 FoC isolates ranged from 51.6 to 84.4 mm after 7 days of incubation at 25±1°C on PDA. The dry mycelial weight q/Tusarium isolates ranged from 56.0 to 252.0 mg. The size of micro and macro conidia ranged from 8.0 – 14.8 X 2.7 – 2.9?m and 17.5 - 26.8 X 4.0 - 4.5 ?m respectively, and diameter of chlamydospores ranged from 5.8 to 9.5?m. The number of microconidia ranged from 4.8 to 28.2 X 10⁴/mm² and macroconidia ranged from 1.40 to 6.8 X 10⁴/mm² on PDA 15 days after incubation at 25±I°C.