Factors affecting germination of Diplotaxis erucoides and their effect on selected quality properties of the germinated products

Abstract Wall rocket (Diplotaxis erucoides) is a wild vegetable with potential as a crop. Its seeds present secondary dormancy mechanisms that can become essential for the survival of wall rocket as a weed or in the wild. However, adaptation to crop conditions requires high and synchronised germination. The present work was aimed at studying whether different treatments improve the germination success of wall rocket seeds, and the effects on subsequent crop quality (morphology, yield, ascorbic acid and phenolics). By using of a L8 orthogonal array design, the main effects of soaking the seeds, scarification with sodium hypochlorite (NaClO), gibberellic acid (GA3), potassium nitrate (KNO3), cold, and heat treatments on germination traits of wall rocket were evaluated. NaClO scarification was the most efficient treatment and significantly increased the early and final germination, the germination rate and the vigour index. The best germination results were obtained when the NaClO scarification was followed by application of GA3. Thus, a protocol consisting on scarification with 2.5 % NaClO for 5 min followed by treatment with 150 ppm GA3 for 24 h was proposed to improve wall rocket germination success. In addition, the germination treatments did not greatly affect the agronomic characters of baby-leaf plants. Scarification with NaClO reduced the days to harvest but did not affect the yield, so its use could have commercial benefits. Moreover, the content in ascorbic acid increased in treatments using NaClO, which may increase the added value of the potential crop. Overall, this study contributes to the domestication of wall rocket by providing a simple germination method that in addition has potential beneficial effects for crop quality.