Evaluation of Nodulation Efficiency of Indigenous Rhizobium Isolates on Green Gram Varieties

Studies were conducted at Department of Plant Pathology, Yezin Agricultural University from July 2016 to April 2017 to evaluate the nodulation efficiency of indigenous rhizobium isolates on green gram varieties. Fifty-two soil samples were collected from green gram fields in Yinmarpin, Palae, Salingyi, Butalin and Monywa Townships in Sagaing Region. Nodulation efficiency of 52 rhizobium isolates was measured on plant growth of Yezin-11 variety by using Completely Randomized Design (CRD) with four replications. All tested isolates showed great variation in their capacity to produce nodules and shoot dry matter. YMP 1, YMP 7, YMP 11, PLE 1 and PLE 5 were found to be effective isolates to enhance the growth of Yezin-11 variety. These isolates were evaluated their effectiveness on five green gram varieties - MAS-1, Yezin-1, Yezin-9, Yezin-11 and Yezin-14 by using 7 x 5 x 3 factorial CRD arrangement (including N+ and N- control treatments). This study revealed that the responses of five rhizobium isolates were varied depending on green gram varieties. In all tested green gram varieties, YMP 11 isolate resulted in higher symbiotic effectiveness and increased shoot dry weight (%) over N+ control than other tested isolates. The higher symbiotic effectiveness of YMP 11 isolate is an indication that such isolate may be better compatible and thus may have potential as source of rhizobium inoculant