Population Levels of Indigenous Bradyrhizobia Nodulating Promiscuous Soybean in two Kenyan Soils of the Semi-arid and Semi-humid Agroecological Zones
Year: 2006
Type: article
Abstract: Soybeans grown in Africa have been selected to nodulate effectively with indigenous Bradyrhizobium spp.populations since Bradyrhizobium japonicum populations are considered absent or in very low numbers in African soils.The major objective of this study was to estimate total population of Bradyrhizobia specific to soybean in two agro-ecologically different study sites, Kiboko in Makueni District, Southeast Kenya (semi-arid to arid conditions) and Kaguru in Meru District, East Kenya (semi-humid climate) .The population of the indigenous rhizobia specific to soybeans was determined using the Most Probable Number (MPN) plant infection technique.In these experiments, the total Bradyrhizobia populations, the population sizes of taxonomically defined slow-growing Bradyrhizobia specific to soybean and the population sizes of Bradyrhizobia spp.specific to tropical Glycine Cross (TGx) varieties were determined for the two study sites.Cowpea, Vigna unguiculata, cultivar Ken Kunde I was used to estimate the total Bradyrhizobia spp.population.Clark soybean, Glycine max, was used to estimate the population sizes of taxonomically defined slow-growing Bradyrhizobia spp.specific to soybean while a TGx genotype, SB12-TGx1869-31E was used to determine the population sizes of Bradyrhizobia spp.specific to TGx varieties.The results of the MPN counts indicated that the total Bradyrhizobia population in Kiboko was between 2.59x10 4 and 1.89x10 5 .The population size of taxonomically defined slowgrowing Bradyrhizobia in Kiboko was between 2.59x10 2 and 1.89x10 3 cells per gram of soil sample while the approximate Bradyrhizobia population specific to TGx genotype was between 7.81x10 2 and 5.67x10 3 cells per gram of soil.In Kaguru, the approximate total Bradyrhizobia population was between 1.04x10 2 and 7.56x10 3 cells per gram of soil.The population size of taxonomically defined slow-growing Bradyrhizobia was be-
Source: Der Tropenlandwirt
Institutions: Kenyatta University, Universität Trier
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDGs: Zero hunger, Life on land
Open Access status: diamond
OpenAlex ID: W1490164975