Wild and cultivated strawberries: diversity, pigments and metabolic change.

ARIAS, M. E.; LUQUE, A. C.; FERNÁNDEZ DATTOLI, L.F.; DEBES, M. A.

Strawberries: Cultivation, Antioxidant Properties and Health Benefits.

NOVA PUBLISHER

Lugar: Hauppauge, New York; Año: 2014; p. 215 - 238

The wild strawberry-like species are important genetics resources for breeding programs. The plasticity and adaptability of native germplasm for biotic and abiotic interactions is high; several breeding programs are tending to transfer this characteristic to cultivated strawberries. Colored fruits and their resistance to disease are characters procured. In north-western of Argentina the wild strawberry (Subtribu Potentillineae, Rosaceae) are represented by Fragaria vesca L., Duchesnea indica Andrews (Focke) and Potentilla tucumanensis Castagnaro&Arias. Recently, new white-fruited genotypes of F. vesca and D. indica were founded in Sierras de San Javier ? Tucumán. Those species, together with Fragaria virginiana, Fragaria chiloensis and several varieties of Fragaria x ananassa are conserved in the Active Germplasm Bank of strawberries (BGF-UNT). The compatibility relations between wild strawberries-like species and varieties of F. x ananassa, and the putative hybrids were analyzed. Numerous crosses between F. vesca - F. x ananassa, F. x ananassa - D. indica, F. chiloensis - F. virginiana and F. x ananassa - F. x ananassa were performed in both directions. Pistils evaluations and the number of achenes germinated suggest different levels of compatibility Pre and post zygotic. Hybrids plants of nine interespecific combinations were confirmed by morphological and anatomical characters and molecular markets (SSR). The red color of flowers and fruits in most plants is due production of anthocyanin or betacyanin. Those pigments derived from the flavonoids pathway are very important in plant defense. In the wild strawberries-like species, the color is related to pigment accumulation; in our laboratory the cause of red- or white-fruit color was studied: the colorless of fruits is due an impair in the encoding enzymes genes, which deviate the biosynthesis pathway of flavonoids towards others compounds. In several cases, the native germplasm presents higher resistance levels to fungal disease than cultivated strawberries. Biochemically, the plantpathogen interaction between wild or cultivated strawberry and Colletotrichum sp (fungi), were analyzed in red-and white-fruited genotypes. Our results suggest that the defense mechanism of plants begins with the peroxides (H2O2) and superoxides (O3-) accumulations. The ephemeral oxidative burst in foliar surface, minutes or hours postinoculation, evidenced accumulations of those reactive species Oxygen (ROS). Physiological and histological studies of plant-pathogen interaction between wild or cultivated strawberries and Colletotrichum isolated were made in our laboratory. These results suggest metabolic changes such as starch accumulations and increased lignin synthesis in parenchyma cells of leaves, petiole or stolons. The plant interaction with fungal elicitor, obtained from Colletotrichum isolated, were also analyzed. All modifications in plant-pathogen interaction depended of genotype of strawberries and the type fungal isolated from Colletotrichum sp.