Plant growth promoting traits in native actinomycetes from Lotus tenuis rhizosphere

SOLANS, M.; VOBIS, G.; WALL L. G.

Avances en estudios básicos y aplicados sobre PGPR en Latinoamérica

UNRC, UNQ,UAntioquia

Año: 2014; p. 9 - 15

Previous studies on actinorhizal and legume plants showed a growth promotion and a higher nodulation in co-inoculation assays with native actinomycetes from Patagonia. To study the corresponding conditions in the Flooding Pampa, it is proposed to isolate saprophytic actinomycetes strains from the rhizosphere of Lotus tenuis, and characterize their potential capacity as Plant Growth Promoting Rhizoactinomycetes. Saprophytic actinomycetes of the rhizosphere (?rhizoactinomycetes?) of L. tenuisgrowing in the Flooding Pampa were isolated applying different methods. A total of 32 actinomycete isolates were obtained. All of them were positive for IAA production; twelve strains showed positive reactions for cellulose and hemicellulose degradation, and nine isolates were positive for phosphate solubilization. Sixteen strains presented the ability to fix atmospheric N2andeight of them were selected for other physiological tests, such as ACC-deaminaseactivity, siderophore production and antifungal activity. All gave positive results, including one Actinoplanes strain and seven Streptomyces strains. These results show the presence of actinomycetes in forage soils and their potential capacity as PGPR. It could be confirmed that these are novel rhizoactinomycetes in terms of soil microorganisms with potential agronomic applications.