Potential of wall rocket (Diplotaxis erucoides) as a new crop: influence of the growing conditions on the visual quality of the final product

Abstract

[EN] Wild edible plants can be used for developing new crops and diversifying food markets. Wall rocket (Diplotaxis erucoides) is an annual weed with potential as a new crop. The present study aims at evaluating the effects of different growing conditions in the visual quality of this potential new crop. We evaluated eleven accessions of wall rocket, together with commercial rocket accessions (Eruca sativa and D. tenuifolia). Experiments were simultaneously conducted under field and greenhouse systems, and performed during two seasons. Fifteen descriptors related to leaf size, colour and shape were evaluated. Analysis of variance detected significant differences in size and shape among the three species studied, revealing the distinctiveness of wall rocket from the other rocket crops. This distinctiveness may enhance its establishment as a new crop. Comparison between the wall rocket accessions was also performed. There was relatively low morphological diversity among them. By contrast, the growing conditions had a high effect on the visual quality, especially for colour related traits and intensity of lobation, and also in the flowering time. As a consequence, the heritability estimates were low to moderate. The principal component analysis (PCA) clustered accessions according to the growing conditions, thus reinforcing the importance of environment in the morphology of wall rocket. The most promising quality of the leaves was obtained under field conditions, where the bright green colour and intensity of lobation were enhanced. In particular, accession DER006-1 was identified as a good candidate for developing a new cultivar. These results establish a basis for the management of wall rocket as a new crop. At the same time, results regarding the low diversity registered for morphology in the accessions evaluated have important implications for future breeding programmes of wall rocket.