Assessment of Maize (Z<i>ea mays</i> L.) <i>Exserohium Turcicum</i> (Pass.) Leonard and Sugg. Isolates on Different Culture Media in Tanzania

Abstract

Morphological characteristics of twenty five isolates of E. turcicum collected from Kilimanjaro, Arusha, Morogoro, Iringa, Njombe and Mbeya Regions in Tanzania were studied in four solid media namely; V8 vegetable juice agar, malt extract agar, maize leaf extract agar and potato dextrose agar. The experiment was conducted twice and replicated three times (3 replicate × 25 isolates × 4 media) for each medium, making a total of 300 plates. The inoculated cultures were arranged in a Complete Randomized Design (CRD) and incubated at 25±1°C. The statistically significant differences (P ≤ 0.05) in colony growth, conidia germination, dry mycelial weight and rate of sporulation on the four solid media indicated the possibility of different strains of E. turcicum in the studied areas. However, colony growth was aggressive in V8 juice agar (5.7 cm) but conidia germination and rate of sporulation were high in malt extract agar. No isolate of E. turcicum germinated or sporulated on PDA. Isolates such as KHK10, KHK18, KHN17, KHN3, KMM18 (Kilimanjaro Region), MMU13 and MRI4 (Mbeya Region), INM8 (Iringa Region) and MMM18 from Morogoro Region significantly yielded more colony growth, conidial germination, sporulation and dry mycelia compared to the other isolates. Molecular studies are needed to confirm the genetic variations amongst the isolates for sustainable maize breeding in Morogoro, Tanzania.