Histopathology of the resistance to colletotrichum gloeosporioides of wild strawberries and species related to commercial strawberry

PARDO, E.M.; GRELLET-BOURNONVILLE, C.; SALAZAR, S. M.; CASTAGNARO, A.P.; DIAZ RICCI, J.C.; ARIAS, M.E.

AUSTRALIAN JOURNAL OF CROP SCIENCE

SOUTHERN CROSS PUBL

Año: 2012 vol. 6 p. 1147 - 1153

1835-2693

Three species of wild strawberries, as well as three related species, were tested against virulent isolate of Colletotrichumgloeosporioides. The purpose of this study was to assess genetic resources exhibiting resistance to anthracnose. The results ofinoculation experiments showed that the species Fragaria vesca, Fragaria virginiana and Fragaria chiloensis were susceptible tofungi; whereas species Duchesnea indica, Duchesnea chrysantha and Potentilla tucumanensis showed higher levels of resistance. Ahistopathological study revealed a different response between susceptible and tolerant species. A significant thickening of the cellwall in epidermal cells, changes of stomata and mesophyll cells, the presence of idioblastic cells with unknown content and theaccumulation of large starch grains in atypical tissues, namely, stomata and parenchyma cells, were observed in species of the genusDuchesnea. However, no morphological alteration was observed in Fragaria species or in P. tucumanensis, which did not show anyapparent interaction with the isolate of C. gloeosporioides. Oxidative burst was evaluated in leaf tissues with the fluorescent probeDCFH-DA (2?,7?-Dichlorofluorescein diacetate) in susceptible and tolerant genotypes. Results showed that tolerant species present anoticeable accumulation of H2O2 whereas susceptible species did not. These results have led us to the conclusion that the changesobserved were correlated with the resistance to disease.