Compatibility of endophytic bacteria with Mesorhizobium ciceri R26 in chickpea (Cicer arietinum)

SARDO M.F.; RUIZ O.A.; MONTEOLIVA M.; VALETTI L.

ROSARIO

Congreso; RAFV Conference 2023; 2023

SOCIEDAD ARGENTINA DE FISIOLOGIA VEGETAL

Worldwide one of the most limiting factors for chickpea productivity is the Ascochyta blight, a fungal disease caused by Ascochyta rabiei. In optimum conditions of humidity and temperature for fungal growth, Ascochyta can produce yield loss of 100%. Our group have beneficial bacteria with the capacity to control that disease. However, we do not know if they are compatible with biological nitrogen fixers (Mesorhizobium ciceri) usually inoculated to chickpea crops. This project aimed to assess the compatibility to produce functional nodules of M. ciceri R26 and biocontrol bacteria (called NKG-50, HFG-8, FH1 and FR2). Pot experiments were carried out with a completely randomized design (n=6). Sterile vermiculite inoculated with 1 ml of saturated culture of M. ciceri R26. Chickpea seeds were germinated in sterility and transplanted to the pots while inoculated with the bacteria suspension (1x109 ufc/ml). Once transplanted, seedlings were irrigated with 0.5X Hoagland solution (with or without N). After 30 days, plants were harvested. Nodules number, dry weight, and percentage of red nodules were evaluated, as well as chlorophyll content (as N indicator), and dry shoot and root biomass.Combined inoculation with FH1 strain and M. ciceri showed significant increase in all nodule related parameters. Root biomass was increased by the combined inoculation of FH1 and FR2 plus M. ciceri, suggesting a growth promoter effect of these isolates. Overall, results suggest that biocontrol bacteria NKG-50, HFG-8, and FH1, isolated from healthy chickpea plants, are compatible with the biological nitrogen fixer M. ciceri R26.