GROWTH AND SPORULATION OF PYRENOPHORA-SEMINIPERDA IN-VITRO - EFFECTS OF CULTURE MEDIA, TEMPERATURE AND PH

The effects of culture media, temperature and pH on in vitro growth an d sporulation of Pyrenophora semeniperda were examined to determine op timal conditions for abundant production of conidia. Radial growth and sporulation (expressed as conidia cm(-2) and conidia colony(-1)) were optimal on modified alphacel culture medium (oatmeal, 10 g; MgSO4.7H( 2)O, 1 g; KH2PO4, 1.5 g; NaNo3, 1 g; coconut milk, so ml; agar, 17 g; distilled H2O, 1 l). Growth occurred over the temperature range 5 to l ess than 35 degrees C and was optimal at 23.2 +/- 0.50. Sporulation oc curred over the range 10 to 30 degrees and was optimal at 19.2 +/- 0.0 5 degrees when expressed as conidia colony(-1), and 18.3 +/- 0.3 degre es when expressed as conidia cm(-2). The pH for maximal growth was 4.7 +/- 0.5. while that for maximal sporulation was 5.4 +/- 0.2 when expr essed as conidia colony(-1), and 5.7 +/- 0.1 when expressed as conidia cm(-2).