New Look at Old Root-Nodule Bacteria: Molecular Techniques Uncover Novel Isolates
Exotic pasture legumes and their associated microsymbionts are important in providing biological nitrogen fixation in Australian agricultural systems. Southern African species of Lotononis from the Listia section can potentially provide sustainable agricultural productivity in systems affected by increasing dryland salinity and climate change. There are eight species in the Listia section: L. angolensis, L. bainesii, L. macrocarpa, L. marlothii, L. minima, L. subulata and L. solitudinis (Van Wyk, 1991). They are perennial, stoloniferous and collar-nodulated. The root-nodule bacteria (RNB) isolated from several of these species are pigmented and the symbiosis between these RNB and their hosts is highly specific (Yates et al., 2007). Pioneering work on L. angolensis, L. bainesii and L. listii isolates was performed in Africa in the 1950–60s by Botha (Kenya), Sandman (Zimbabwe) and Verboom (Zambia) and in Australia (Norris, 1958).