Bagheri M.,Islamic Azad University at Maragheh |
Saber M.,Islamic Azad University at Maragheh |
Ueckermann E.A.,ARC Plant Protection Research Institute ARC PPRI |
Ueckermann E.A.,North West University South Africa |
And 3 more authors.
International Journal of Acarology | Year: 2011
A new species of Eustigmaeus Berlese, 1910 (Acari: Stigmaeidae), Eustigmaeus setiferus n. sp., is described and illustrated from soil in apple orchards at Maragheh, East Azerbaijan Province, Iran. © 2011 Copyright Taylor and Francis Group, LLC.
Hassen A.I.,ARC Plant Protection Research Institute ARC PPRI |
Bopape F.L.,ARC Plant Protection Research Institute ARC PPRI |
Habig J.,ARC Plant Protection Research Institute ARC PPRI |
Lamprecht S.C.,ARC Plant Protection Research Institute ARC PPRI
Biology and Fertility of Soils | Year: 2012
Rooibos (Aspalathus linearis) has been reported to be nodulated by rhizobia belonging to members of the genus Bradyrhizobium but based solely on slow growth rate on growth media in vitro. Because there is very little information about the rhizobia that nodulate and fix nitrogen in rooibos, the characterization of rhizobial strains and their ability to nodulate A. linearis was investigated in this study. Soils intially collected from the rhizosphere of different Aspalathus populations were used in a baiting experiment to trap rhizobia by rooibos roots. The rhizobia trapped in the nodules were re-isolated and used in Koch's postulate experiment using the Leonard jar assembly in the glasshouse. The strains that formed on the average between five and 12 indeterminate pink nodules per plant resulted in statistically significant (P = 0.05) increase in shoot and root dry weights. Phylogenetic analysis of the 16S ribosomal RNA sequence of the isolates from the root nodules revealed for the first time that A. linearis is nodulated by different groups of rhizobia belonging to members of both the α-Proteobacteria and the β-Proteobacteria. It was also found that only 2% of the total rhizobia isolated from the root nodules of rooibos were represented by the genus Bradyrhizobium. The finding that rooibos is nodulated by different groups of α-rhizobia and β-rhizobia provides valuable information both in the study of the microbial ecology of rooibos and in the selection of highly efficient nitrogen fixing strains for the commercial cultivation of this indigenous legume. © 2011 Springer-Verlag.