Phaseolus lunatus is nodulated by a phosphate solubilizing strain of Sinorhizobium meliloti in a Peruvian soil

Abstract

The genus Phaseolus includes several species indigenous to American continent that belong to family Leguminosae. This genus includes several species, some of them only cultivated in American countries. This is the case of Phaseolus lunatus. This plant can be nodulated by fast and slow growing rhizobia. At the moment the fast growing species nodulating Phaseolus commonly belong to genus Rhizobium and more rarely to Sinorhizobium fredii. A strain, LMTR32, isolated from Phaseolus lunatus growing in Peru soils showed a high ability to solubilize bicalcium phosphate from YED-P plates. The 16S rRNA sequence of this strain showed a 100% similarity with the type strain of Sinorhizobium meliloti. The LMW RNA profile of this strain is identical to that of type strain of Sinorhizobium meliloti and confirms that the strain LMTR32 belongs to this species. More studies are necessary in order to establish the prevalence of this species in nodules of Phaseolus lunatus in Peru´, and, in the future, it will be very interesting to perform wider taxonomic studies of rhizobia nodulating Phaseolus in different American countries.