Beneficial effects of Trichoderma genus microbes on qualitative parameters of Brassica rapa L. subsp. sylvestris L. Janch. var. esculenta Hort.

The consumption of vegetables and fruits has always been seen as health promoting. One group of vegetables that were already used for medicinal purposes in ancient times and are now seen as possibly cancer protective are vegetables of the Brassica genus. The protective effect of brassicas against cancer may be due to their relatively high content of glucosinolates. Certain hydrolysis products of glucosinolates have shown anticarcinogenic properties. However, not properly cooking procedures and storage could drastically reduce the content of glucosinolates in Brassicaceae plants. This study aims to assess whether the use of agronomic techniques can increase the content of glucosinolates in Brassica plants, in order to offset these losses. For this purpose were used strains of beneficial microorganisms of Trichoderma harzianum TM10, T. atroviride P1, already known biocontrol agents, and their metabolites harzianum acid and 6-pentyl-α-pyrone on plants of Brassica rapa subsp. sylvestris var. esculenta ecotype “Sessantino” (called with the trivial name “friarielli” in the south of Italy where this variety is very popular and consumed). Moreover, the antioxidant activity and ascorbic acid content were determined on plant extracts, followed by liquid chromatography–mass spectrometry analysis of glucosinolates. In order to obtain the extraction of constituents from plant material, microwave-assisted extraction was used. Results obtained showed that the use of Trichoderma and its metabolites determined an increase in glucosinolates in plants of B. rapa. Accordingly, the proposed method could be used on other plants of food interest to increase their nutritional properties.