Nodulation Process, Nitrogen Fixation, and Diversity of Fenugreek Rhizobia

Abstract

Trigonella foenum-graecum is a medicinal and culinary plant with varied health benefits. The improvement of its growth in weak soils depends on symbiotic soil bacteria called rhizobia which contribute to the autonomy of legumes towards nitrogen. Biological nitrogen fixation is one of the most beneficial processes for legumes. This process allows the plant to become autotrophic to nitrogen, one of the most limiting components for growth. Thus, the Fabaceae have acquired the possibility to invade and settle in areas and regions which are difficult for the cultivation and growth of other plants. It was found a great phenotypic diversity of fenugreek rhizobia and they were more tolerant to environmental stresses than the reference strains. Also a number of molecular methods have been discussed to reveal the genetic diversity of different strains, species, genera or families of rhizobia.