CHARACTERIZATION AND PATHOGENICITY OF BIPLOLARIS SOROKINIANA CAUSED SPOT BLOTCH OF WHEAT IN PAKISTAN

Abstract

Biplolaris sorokiniana is a hemibiotroph pathogen (teleomorph: Cochliobolus sativus) causes spot blotch of wheat. It is considered as severe pathogen of foliar disease in warm and humid areas and also causes significant losses in South Asian Countries. The pathogen collected from foliar samples of wheat field for identification of fungus associated with symptoms on foliage that characterized on the basis of colony color, texture and conidial morphology. Color and growth of colony was grayish black and suppressed type respectively. Conidiophores were unbranched, septate and conidia brown to olivaious brown in color. Complete diagnosis is done by performing Koch’s postulates. Characteristic symptoms expressed by plant were brown to dark brown spots on leaves, also on roots and there was no chlorotic margin at initial stage of spot formation. After performing Koch’s postulates it was confirmed that Bipolaris sorokiniana was causal agent spot blotch or Helminthosporium Leaf Blight of wheat.