Jornal de Patologia Vegetal e Microbiologia

Abstrato

Morphological Variation and Basic Characteristics of Selected Indigenous Rhizobia Isolated from Major Chickpea (Cicer arietinum L.) Growing in Regions of Ethiopia

Zehara Mohammed Damtew

Chickpea (Cicer arietinum L.) is a major legume crop in Ethiopia and provide multiple benefits, due to high nutritive value as well as the ability of the crop to enrich nitrogen poor soils due to biological nitrogen fixation with different Rhizobia isolates. However, the effectiveness of the isolates varies due to inherent feature, stress tolerance and substrate utilization characteristics of the isolates. This necessitates the screening of the basic properties of the isolates under in vitro laboratory conditions. To this effect, 15 indigenous isolates from chickpea growing regions were tested for in vitro basic features, stress tolerance and substrate utilization properties. There were variations in morphological features, stress tolerance and nutritional diversity among isolates. The isolates also formed colony with circular shape, entire margin, white large creamy mucoid to watery small creamy mucoid texture. Chickpea isolates showed broad range (0-100%) salt tolerance to different NaCl concentrations. The isolates grown in moderately acidic pH 4.5 to alkaline pH 7.5 ranging from (25-50%). Subsequently the isolates were grown at optimum temperature up to 37°C level range from (25-100%). The isolates were more tolerant to the tested antibiotics (0-75%) and resistance to the heavy metal (0-100%). In addition, chickpea isolates better utilized the carbohydrates (0-100%) and similarly, the amino acids (25-75%). All taken together, the data provided an important complement to select representative isolates competitive in the soil which is a one of the desirable characteristics for inoculant isolates selection for effective nitrogen fixation.