a b s t r a c tExtracts of the white shaft and green leaves of 30 leek cultivars were investigated for their antioxidant properties, total phenolic (TP) and L-ascorbic acid (AA) content. The measured antioxidant properties included free radical scavenging activities against peroxyl (ORAC) and 2,2-diphenyl-1-picrylhydrazyl radicals (DPPH) and their Fe 3+ reducing capacity (FRAP). The results from this study suggest that the green leek leaves generally have significantly stronger antioxidant properties than the white shaft. Correlation analysis between the TP and the AA content and the antioxidant activity showed that phenolics and ascorbic acid contribute significantly to the antioxidant activity of leek. The three antioxidant activity assays were all correlated for the extracts of the white shaft of the 30 leek cultivars. Principal component analysis (PCA) elucidated the influence of part and type of cultivar on the antioxidant capacity, TP, and Lascorbic acid content, whilst the breeding strategy and seed company had no influence.

No abstract

Belgian agriculture could decrease its heavy dependency on imported protein crops by a local production of soybean. Unfortunately, soybean production is hampered by Belgium's short and cold growing season. We evaluated 409 varieties, breeding lines and genebank accessions planted at two planting dates in a row-plot experiment to explore the genotypes that are suitable for growing in Belgium. The current MG000 varieties may require additional crossings with very early-maturing genotypes to guarantee an optimal and safe harvest. Within such crossings, care must be taken to maintain the indeterminate or semi-determinate growth habit. Vegetative development was negatively correlated with flowering date and maturity date, but positively correlated with cold tolerance. Seed quality was mainly affected by mould infection (associated with strong lodging and late maturity) and mottling caused by soybean mosaic virus. Planting 3 weeks earlier resulted in 8 d earlier flowering and 7 d earlier maturing, without significant losses in seed yield per plant. The results of this row-plot experiment hold promise to select for genotypes adapted to the Belgian conditions.

Extracts of 31 leek cultivars were analyzed using liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to determine the distribution of the two most abundant S-alk(en)yl-l-cysteine sulfoxides (ACSOs) in leek, that is, isoalliin and methiin. The isoalliin concentration of the white shaft and green leaves of the 31 leek cultivars varied from 15 to 53 mg/g dry weight (dw) and from 9 to 45 mg/g dw, respectively, whereas the methiin concentration varied from 3 to 16 mg/g dw and from 1 to 10 mg/g dw, respectively. Leek cultivar and tissue had an effect on the ACSO amounts. Cultivars Artico and Apollo F1 rated highest for the mean isoalliin and methiin concentration, respectively. In general, the whole leek plant of the winter leek cultivars contained a significantly higher ACSO amount than the summer and autumn cultivars. To determine whether this difference was attributed to the cultivar background or time of harvest, ACSOs were also quantitated in nine leek hybrids at four different stages during the next growth season. The amounts of ACSO changed significantly during the growth season, indicating the importance of harvest at specific time moments, although there was still an effect of cultivar on the ACSO amounts.

Celeriac F1 hybrid seed production is currently complicated due to the instability of cytoplasmic male sterile lines. To develop alternative alloplasmic CMS lines, an asymmetric protoplast fusion and hybrid screening methodology was established. Celeriac suspension cells protoplasts were used as the acceptor and carrot, coriander and white celery mesophyll protoplasts as the donor for protoplast fusion experiments. Acceptor cytoplasmic inheritance was inhibited by iodoacetamide treatment and donor nuclear genome inheritance was prevented by UV exposure. Protoplasts were selectively stained and fused using electroporation and polyethylene glycol, and candidate hybrid shoots were obtained. One chloroplast and three mitochondrial markers that could distinguish acceptor and donors organelles were used to characterize over 600 plants obtained after fusion events, without identifying any cybrid. In order to increase the testing efficiency a high number of micro plantlets were pooled and hence the presence of the carrot specific Atp1 marker in one of the pooled samples was detected. We demonstrated that fusion took place between celeriac and a carrot indicating that the creation of viable hybrids is possible although at a very low frequency. These findings open the path for new cytoplasmic hybridization and the isolation of novel CMS lines of celeriac.