Strain diversity of rhizobia occupying lucerne and Caucasian clover nodules in high country soil in New Zealand

Abstract

In New Zealand, low soil pH coupled with toxic levels of aluminium limit establishment and maintenance of legumes on about 500,000 ha of farmed high country land (Moir and Moot 2010). This is attributed to poor nodulation and nitrogen fixation, particularly in the presence of aluminium (Flis et al. 1993). In this study, lucerne and Caucasian clover nodulation were assessed in an acidic high country soil. The collected bacterial isolates from lucerne and Caucasian clover nodules were identified to investigate the effect of soil pH and Al on the genetic diversity of bacterial isolates within the nodules.