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Capítulo IV
Endophytic establishment of the entomopathogenic fungus
Tolypocladium cylindrosporum in tomato and bean plants
Noemí Herrero Asensio, Salud Sánchez Márquez, Iñigo Zabalgogeazcoa
Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA-CSIC), Cordel de
Merinas 40-52, 37008 Salamanca, Spain
Abstract
The purpose of this work was to test if two strains of T. cylindrosporum, originally
isolated as endophytes from grasses could be artificially inoculated, and behaved as
endophytes in tomato or bean plants. T. cylindrosporum strains 11-1L and 11-0BR were
reisolated from leaf fragments of both plant species up to 35 days after their inoculation
with a concentrated suspension of 1 x 10 8 conidia/ml. Both fungal strains were isogenic,
differing only in the mycoviral infection by the Victorivirus TcV1 harboured by 11-1L,
strain 11-0BR was virus-free. The influence of TcV1 in the endophytic capability of T.
cylindrosporum was also evaluated. A significant interaction was observed among the
mycovirus infection and the capability of each strain to infect each plant host. Virus
infected T. cylindrosporum strain 11-1L penetrated better in bean plants than the virus-free
strain (11-0BR). The opposite tendency was observed in tomato plants, where the virus
free strain penetrated better than the infected strain.
Introduction
.
Endophytes are a group of fungi occurring inside plant tissues without causing any
apparent symptoms to them. Nonetheless, several roles have been attributed to endophytic
fungi, like providing resistance to abiotic stresses (Rodríguez et al., 2009), protection
against plant pathogenic nematodes and fungi (Elmi et al., 2000; Wicklow et al., 2005;
Zabalgogeazcoa, 2008), or protection against herbivorous insects (Vega et al., 2008). The