In vitro mycelium growth variation among Fusarium graminearum isolates causing head blight of wheat in India

Abstract

Fusarium head blight (FHB) or head scab is one of the most destructive fungal diseases of wheat (Triticum aestivum L.) worldwide. One hundred ten diseased samples were collected from naturally infected wheat varieties planted at Indian Agricultural Research Institute, Regional Station, Wellington, the Nilgiris hills and Lahaul Valley (Himachal Pradesh) during 2018 and 2019. Twenty-nine Fusarium isolates were obtained, purified through hyphal tip culturing technique and maintained on potato dextrose agar (PDA) media. Morphological characters viz., colour of the mycelia, growth rate and pigmentation wasstudied. Colour of the mycelia produced by different isolates varied from light pink, pink, dark pink to brownish pink. All isolates produced pink pigmentation on PDA. Out of 29 F. graminearum isolates used in present study, 23 isolates belonged to Wellington which reached maximum mycelium growth of 85 mm after 144 h of incubation. Maximum mycelium growth in Lahaul valley isolates Fg-L1 and Fg-L2 was recorded 63 and 62.7 mm, respectively after 144 h. Present study revealed variation in mycelium growth rate among F. graminearum isolates belonged to Lahaul valley of Himachal Pradesh and Wellington, the Nilgiris, Tamil Nadu.