BISERRULA-PELECINUS L - A LEGUME PASTURE SPECIES WITH POTENTIAL FOR ACID, DUPLEX SOILS WHICH IS NODULATED BY UNIQUE ROOT-NODULE BACTERIA

Biserrula pelecinus is a monotypic genus which displays agronomic potential for acid, duplex soils. Whilst it is widespread in the Mediterranean basin, it represents a new pasture legume to Australia. The root-nodule bacteria isolated from B. pelecinus nodules collected from Morocco and Sardinia were unique in the sense that they appeared to be specific to this legume. They also grew at a lower pH on an acidified growth medium than the rhizobia for clover, peas and medic, which indicated a potential adaptation to acid soils. B. pelecinus was not nodulated by any of the commercially available species of root-nodule bacteria in use in Australia that we evaluated. Hence, it appears that the development of B. pelecinus for industry will be contingent upon the commercialization of its specific rhizobia. Several genotypes of B. pelecinus produced vigorous growth and high seed yields at two field sites in the wheatbelt of Western Australia, which received less than 250 mm rainfall in 1994.