Raspberry breeding and biotisation for increasing plant stress tolerance and antioxidant activity
Résumé
Chemical inputs used in red fruit production can be detrimental to the environment and pesticides are not always efficient in controlling plant diseases. In addition, it is suspected that conventional agricultural practices have a negative impact on antioxidant activities in red fruits. Therefore new cultural approaches are required in order to produce red fruits of high quality. This involves an integrated programme of plant breeding and development of sustainable agricultural practices. Antioxidant activity was compared in leaves and berries of six raspberry cultivars for the selection of varieties for a breeding programme. This showed that cultivars that had the highest antioxidant activity in leaves had the lowest activity in berries. Biotisation is a new complementary biotechnological approach, which consists of inoculating young plants with beneficial microorganisms such as bacteria and mycorrhizal fungi for improving plant growth and tolerance to biotic and abiotic stresses. Biotisation at the step of acclimatisation of in vitro produced plantlets was shown to be efficient in increasing plant growth and water content in plant leaves grown under low nutrient conditions. A PCR-based diagnostic test was used to check the presence of inoculated mycorrhizal fungi and the absence of P. fragariae var. rubi in plant roots.