Bio-inoculation of yerba mate seedlings (Ilex paraguariensis St. Hil.) with native plant growth promoting rhizobacteria: a sustainable alternative to improve crop yield

BERGOTTINI VM; OTEGUI MB; SOSA DA; ZAPATA, PD; MULOT M; REBORD M; ZOPFI J; WYSS VF; BENREY B; JUNIER P

BIOLOGY AND FERTILITY OF SOILS

SPRINGER

Lugar: Berlin; Año: 2015 vol. 51 p. 1 - 7

0178-2762

In this study, the role of native plant growthpromoting rhizobacteria (PGPR) as bio-inoculants was assessed as an alternative to ameliorateIlex paraguariensis St. Hill. growth in nursery comparing poorer (soil) versus richer (compost) substrates. Twelve rhizospheric strains isolated from yerba mate plantations were evaluated in vitro for their potential as PGPRs. Three isolates, identified as Kosakonia radicincitansYD4,Rhizobium pusenseYP3, and Pseudomonas putidaYP2, were selected on the basis of their N2fixation activity, IAA-like compound and siderophore production, and phosphate solubilization. A highly significant positive effect of bio-inoculation with the native isolates was observed in 5-month-old seedlings cultivated in soil. The highest increase was observed in seedlings inoculated with K. radicincitansYD4 with an increase of 183 % in the dry shoot weight and a 30 % increase in shoot N content. In contrast, in compost, no increment in the dry weight was observed; however, an increase in content in some macronutrients in shoots was observed. Remarkably, when plant biomass was compared between soil and compost, seedlings inoculated withK. radicincitansYD4 in soil produced the highest yields,even though higher yields could be expected in compost due to the richness of this substrate. In conclusion, bio-inoculation of yerba mate seedlings with native PGPR increases the yield of this crop in nursery and could represent a promising sustainable strategy to improve yerba mate growth in low-fertility soils