Sie befinden Sich nicht im Netzwerk der Universität Paderborn. Der Zugriff auf elektronische Ressourcen ist gegebenenfalls nur via VPN oder Shibboleth (DFN-AAI) möglich. mehr Informationen...
Nodulation of Medicago truncatula and Medicago polymorpha in two pastures of contrasting soil pH and rhizobial populations
Ist Teil von
Applied soil ecology : a section of Agriculture, ecosystems & environment, 2007-02, Vol.35 (2), p.441-448
Ort / Verlag
Amsterdam: Elsevier B.V
Erscheinungsjahr
2007
Quelle
Elsevier ScienceDirect Journals
Beschreibungen/Notizen
The size of the background rhizobial population can often determine the success of field nodulation and persistence of inoculant rhizobia. Field experiments were conducted to determine the nodulation response of annual medics (
Medicago spp.) in a pasture-wheat-pasture rotation when grown in soils of contrasting pH and rhizobial populations.
Medicago truncatula Gaertn. and
M. polymorpha L. were inoculated with one of three different strains of
Sinorhizobium medicae (WSM540, WSM688) or
S. meliloti (NA39) or left uninoculated and sown in two fields of pH (CaCl
2) 5.9 and 7.2 of differing soil rhizobial backgrounds (11 and 7.1
×
10
4
cells/g soil, respectively). Nodulation was assessed in years 1 and 3 of the rotation. At the site with a small rhizobial background,
M. polymorpha nodulated poorly when inoculated with the acid-sensitive strain NA39 but nodulated well when inoculated with acid-tolerant strains WSM688 and WSM540.
M. truncatula had a similar extent of nodulation with each of the rhizobial inoculants. At the site with a large rhizobial background all treatments had greater than 85% of plants nodulated. Nodule occupancies, assessed by PCR, provided further insight: at the site with a small rhizobial background both medic species successfully nodulated with the acid-tolerant strains WSM540 and WSM688 and these strains persisted to year 3. However, at the site with large rhizobial background, only one strain, WSM688, was identified from
M. truncatula nodules in year 3. This study highlights the importance of edaphic constraints and plant–rhizobia interactions to the successful development of nodulation in a field environment.