Bioprospecting foliar endophytic fungi of Vitis labrusca Linnaeus, Bordô and Concord cv.

Abstract

Endophytic fungi colonize the interior of plant tissues and organs, establishing an intimate mutualistic association with no visible symptoms. The fungi may help protect the plant against herbivores and pathogens, making them potentially useful endophytes in the biological control of diseases and agricultural pests. The biotechnological interest in these organisms has stimulated research related to the bioprospecting of endophytic fungi. Grapevine is among the oldest of plants cultivated by man, with the grape being one of the most highly consumed fruits in the world. Diseases cause significant damage to grape cultures, making their integrated control important to reduce the use of pesticides and, consequently, environmental and human contamination. The rustic species Vitis labrusca L. (Vitaceae), used in the preparation of juices and wines, is highly resistant to fungal diseases. We isolated leaf endophytic fungi of the Bordo and Concord cultivars (V. labrusca L.), which were ordered into 68 and 62 morpho-groups of the Bordo and Concord cultivars, respectively. We used scanning electron microscopy to confirm the presence of endophytes in the leaves. Endophytic diversity was analyzed based on sequencing the ITS1-5.8S-ITS2 region of rDNA, allowing the identification of fungi belonging to genera including Cochliobolus, Bipolaris, Fusarium, Alternaria, Diaporthe, Phoma and Phomopsis. Phylogenetic analysis confirmed the identity of the endophytes. The biotechnological potential of endophytes was tested in vitro for the control of pathogenic fungi of grapevines including Alternaria sp., Sphaceloma sp. and Glomerella sp. Inhibition percentages above 50 % as demonstrated by some isolates demonstrate their potential for biological control.