Competitiveness among Rhizobia for Nodulation of Introduced Leguminous Tree Gliricidia sepium in a Sub-Saharan Sandy Soil

Abstract

Agroforestry systems are progressively integrated by small farmer holder to mitigate agricultural production charge and contribute to sustainable agriculture by restoring and maintaining sandy soil fertility. A greenhouse experiment was carried out to test the nodulation level of introduced Gliricidia sepium tree with foreign rhizobial reference strains TAL1769 and TAL1770 against native rhizobial community using PCR/RFLP techniques. Restriction patterns of the two inoculated reference strains obtained for 16S – 23S rDNA - IGS were different to those of indigenous rhizobia detected in all remained nodules collected from root plants regarding the restriction enzymes HaeIII and MspI. Nodule occupancy rates of the reference strains and native rhizobial strains of profile F ranged from 18.36 to 22.45 and were higher compared to others rhizobial strains detected in gliricidia rhizosphere. Therefore, regarding its high competitiveness level, the native rhizobial strain may be considered as a good candidate to inoculate the introduced legume tree gliricidia.