In Vitro Antifungal Activity of Plant Extracts on Pathogenic Fungi of Blueberry (Vaccinium sp.)

Abstract

Three pathogenic fungi of blueberry (<i>Vaccinium</i> spp.) responsible for dieback disease, identified as <i>Pestalotiopsis clavispora</i>, <i>Colletotrichum gloeosporioides</i> and <i>Lasiodiplodia pseudotheobromae</i>, were isolated in the northwestern region of the state of Michoacán, Mexico. The mycelial growth in vitro of these fungi was inhibited by extracts from <i>Lantana hirta</i>, <i>Argemone ochroleuca</i> and <i>Adenophyllum porophyllum</i>, medicinal plants collected in Sahuayo, Michoacán, Mexico. The extracts showed different degrees of inhibition; the most effective were: M5L extract from <i>L. hirta</i> and M6LFr extract from <i>A. ochroleuca</i>, both of which inhibited 100% of the mycelial growth of <i>P. clavispora</i> and <i>C. gloeosporioides</i>; and M4LS extract from <i>A. porophyllum</i>, which inhibited 100% of the mycelial growth of the three pathogens. The extracts were fractionated by thin layer and column chromatography, and the most active fractions were analyzed by gas chromatography-mass spectrometry. The major compounds identified in <i>L. hirta</i> extract were Phytol and α-Sitosterol. The compounds identified in <i>A. ochroleuca</i> were Toluene and Benzene, 1,3-bis(3-phenoxyphenoxy)-. In <i>A. porophyllum</i>, the compound identified was Hexanedioic acid, bis(2-ethylhexyl) ester. These results show the potential of <i>L. hirta</i>, <i>A. ochroleuca</i> and <i>A. porophyllum</i> as a source of antifungal compounds.