Resumen de Selection of Trichoderma spp. isolates antagonistic to Rosellinia necatrix

D. Ruano Rosa, Lidia del Moral Navarrete, C.J. López Herrera

• español

  Se analizó el antagonismo de cincuenta y seis aislados masales de Trichoderma spp. procedentes de cultivos de aguacate (Persea americana Mill.), clavel (Dianthus caryophyllus L.), litchi (Litchi chinensis Sonn), arroz (Oryza sativa L.) y remolacha (Beta vulgaris L.) del Sur de España frente a un aislado de Rosellinia necatrix Prill. Los aislados de ambos hongos se analizaron in vitro en cultivos duales y de celofán, valorándose la procedencia, características culturales, sobrecrecimiento, esporulación y tinción del medio de cultivo. Se seleccionaron 21 aislados masales y se evaluaron sus correspondientes monoconídicos mediante los análisis in vitro citados. Posteriormente se seleccionaron los 8 aislados monoconídicos de Trichoderma que presentaron el mayor antagonismo in vitro. Estos 8 aislados se evaluaron adicionalmente mediante análisis frente a nueve aislados representativos de R. necatrix, procedentes de nueve grupos de virulencia. Estos se obtuvieron mediante análisis de patogenicidad de 57 aislados de R. necatrix procedentes de fincas de aguacate enfermas del Sur de España. Aquellos aislados monoconídicos de Trichoderma podrían considerarse como agentes de control biológico con un alto potencial para un efectivo control de la podredumbre blanca del aguacate.

• English

  Fifty-six bulk isolates of Trichoderma spp. from avocado (Persea americana Mill.), carnation (Dianthus caryophyllus L.), litchi (Litchi chinensis Sonn), rice (Oryza sativa L.) and sugar beet (Beta vulgaris L.) crops located in southern Spain were evaluated for antagonism against one isolate of Rosellinia necatrix Prill. Isolates of both types of fungi were tested in dual and cellophane culture. The origin, cultural characteristics, overgrowth sporulation and staining of growth medium were recorded. As a result, 21 Trichoderma bulk isolates were selected and their corresponding monoconidial isolates were evaluated as above. Next eight monoconidial Trichoderma isolates with the largest in vitro antagonism were selected, and they were additionally tested against nine representative isolates of R. necatrix from nine virulence groups. These were established after pathogenicity tests on 57 isolates of R. necatrix from diseased avocado orchards in southern Spain. These monoconidial Trichoderma isolates were considered as potential biological control agents with a high potential for effective control of white root rot of avocado.