Increasing diversity among Lens species for improving biological nitrogen fixation in lentil

Abstract

AbstractExotic germplasm is a key resource for reintroducing genetic variability into cultivars. We evaluated 36 accessions from cultivated lentil (Lens culinaris Medik.) and six related wild species inoculated with a commercial strain of Rhizobium leguminosarum bv. viciae under greenhouse conditions. The objective was to explore Lens species and/or accessions that can contribute higher biological nitrogen fixation ability to the lentil crop. A split plot design was used with either Rhizobium inoculation, added nitrogen (+N), or neither as the main plots, and accessions in subplots randomized in blocks. Two repeats of the experiment were evaluated at flowering for N fixation and nodulation characters, and two subsequent experiments, with a subset of 14 accessions, were evaluated at maturity for seed production, seed quality, and harvest index. Differences in phenotypic expression corresponded to specific accessions but not to any particular Lens species. CDC Greenstar had the highest N fixation among lentil cultivars and also had superior yield results compared to the added N treatment. When inoculated, wild accessions, including IG 72643 (Lens orientalis), displayed unique and multiple desirable characteristics compared to cultivars, including indeterminate nodulation, higher N translocation, stable yield compared to added N treatment, and exceptionally high protein concentration in seeds.