11. Being a legume capable of symbiosis with Rhizobia , the pigeon pea enriches soil through symbiotic nitrogen fixation. 12. Rhizobia are specific to particular host species although a rhizobia species may often infect more than one host species.13. Rhizobia are specific to particular host species although a rhizobia species may often infect more than one host species. 14. Specific strains of rhizobia are required to make functional nodules on the roots able to fix the N 2. 15. In this interaction, rhizobia bacteria induce root nodule formation in legume plants via an exchange of molecular signals. 16. The word " rhizobium " is still sometimes used as the singular form of " rhizobia " 17. Having this specific rhizobia present is beneficial to the legume, as the N 2 fixation can increase crop yield. 18. As with birds, variation is introduced in each generation of rhizobia through immigration, mutation, and gene transfer. 19. Likewise, wild lupine plants allocate fewer resources to nodules containing less-beneficial rhizobia , limiting rhizobial reproduction inside. 20. Thus, he was able to provide a mixed culture of Rhizobia capable of inoculating plants belonging to several groups.
