SCREENING OF DIFFERENT INOCULATION TECHNIQUES OF THE ENTOMOPATHOGENIC FUNGUS BEAUVERIA BASSIANA AS AN ENDOPHYTE IN NICOTIANA TABACUM PLANT

RUSSO MARÍA LETICIA; FERRERI NATALIA A.; PELIZZA SEBASTIAN ALBERTO; CABELLO MARTA NOEMI; ALLEGRUCCI NATALIA; SCORSETTI ANA CLARA

Mar Del Plata

Congreso; VIII Congreso Argentino de Microbiologia; 2012

Sociedad Argentina de Microbiologia

Endophyte term was proposed by Heinrich de Bary (1884) to define fungi or bacteria that live inside plant tissues without causing apparent symptoms in the host. Endophytes are common in the nature and some of them have demonstrated adverse effects against insects, nematodes and plant pathogens. At present time have been recognized 700 species of entomopathogenic fungi, some of them such as Beauveria, Metharizium and Lecanicillium were isolated as endophytes naturally in several plants, while others have been introduced artificially by using different techniques. The aim of this work was to determine the optimal inoculation techniques: spraying on leaves, stem injection and root immersion. A suspension of 1 x 108 conidia/ml of Beauveria bassiana (LPSC 1067) (Ascomycota: Hypocreales) was inoculated by the different techniques in Nicotiana tabacum L. plants. Colonization of leaves by B. bassiana was assessed 7, 15 and 30 days after inoculation to determine the degree of fungus colonization. Leaves from inoculated and uninoculated control plants were excised and surface sterilized (70% ethanol for 2 min, bleach for 3 min and rinsed with sterile distilled water three times). One leaf from each of the three replicate plants was excised (1 x 1 cm2), placed on PDA plates plus antibiotic and incubated at 20 ºC. Presence of endophyte was determined after 10 days.