Cultural, Morphological and Pathogenic Variability of Colletorichuma kahawae Isolate of Gurage Zone

Abstract

Arabica Coffee is an important crop in the national economy of Ethiopia. Coffee berry disease caused by the fungus Colletotrichum kahawae Waller and Bridge is the most devastating threat to Coffea arabica L. production in Africa at high altitude. Hence, this study was carried out for Variation of a representative Colletotrichum isolates of Gurage zone of major coffee producing areas using cultural, morphological and pathological criteria. Out of 33 sample 13 representative C. kahawae isolates from the study area and one Gera isolate were isolated from infected green coffee berry which showed significant variations in their cultural, morphological characteristics and pathogenicity. Mean radial colony growth rate of isolate showed significant variation (p<0.001) with the range of 2.67 to 4.08 mm/24hrs on PDA in EZA and CA1 isolates, respectively. Conidial size also showed significant difference (p<0.001) in the range of 5 to 6.04 and 9.24 to 10.0 µm in width and length, respectively. Similarly, conidia production varied from 182.25 to 432.92 × 104 conidia/ml of isolate EK1 and EZD, respectively. All isolates were found to be pathogenic to Arabica coffee with highly significant variation (P < 0.01) and infection percentage in the ranges of 45.83 to 68.06%. Aggressive isolate EZD should be used for screening of coffee variety for CBD resistance evaluations.