Rapid separation of seed glucosinolates from Camelina sativa by thin layer chromatography

A thin layer chromatography (TLC) method has been developed for the quantitative analysis of glucosinolates extracted from <em>Camelina sativa</em>. This procedure resolves the same long-chain glucosinolates as high-performance liquid chromatography but increases simultaneous sample size to 18. The TLC method saves time and solvent, and can be applied to screening of <em>Camelina</em>.

Extraction and Identification of Isothiocyanates from Broccolini Seeds

Broccolini ( Brassica oleracea Italica x Alboglabra) is a cross between broccoli and kai-lan (Chinese broccoli), which contains abundant glucosinolates. The intact glucosinolates are believed to be inactive, while their hydrolysis products, such as isothiocyanates (ITCs), are found to have bacteriocidal and anticarcinogenic activities. So far, no report is available about generation of ITCs during the process of glucosinolate hydrolysis in broccolini. In this study, the hydrolysis of broccolini seed glucosinolates was investigated under controlled conditions of pH, time and temperature, and the ITCs produced were determined. The results showed that an optimum hydrolysis of glucosinolates could be achieved at a temperature of 25°C, at pH 7.0, and a reaction time of eight hours. Furthermore, GC-MS analysis indicated that the extracted ITCs primarily were: 3-BITC (3-benzyl-ITC) (10.8%), 4-methylpentyl-ITC (0.5%), 1-isothiocyanato-butane (26.8%), PEITC (phenethyl-ITC) (22.6%) and SFN (sulforaphane) (19.2%).

Homoeologous loci control the accumulation of seed glucosinolates in oilseed rape (Brassica napus)

The genetic control of seed glucosinolate content in oilseed rape was investigated using two intervarietal backcross populations. Four QTLs segregating in the population derived from a Brassica napus L.'Victor' × Brassica napus L.'Tapidor' cross, together accounting for 76% of the phenotypic variation, were mapped. Three of these loci also appeared to control the accumulation of seed glucosinolates in a Brassica napus L. 'Bienvenu' × 'Tapidor' cross, and accounted for 86% of the phenotypic variation. The three QTLs common to both populations mapped to homoeologous regions of the B. napus genome, suggesting that seed glucosinolate accumulation is controlled by duplicate genes. It was possible to extend the comparative analysis of QTLs controlling seed glucosinolate accumulation by aligning the published genetic maps generated by several research groups. This comparative mapping demonstrated that high-glucosinolate varieties often carry low-glucosinolate alleles at one or more of the loci controlling seed glucosinolate accumulation.Key words: backcross, comparative mapping, genetic linkage map, marker-assisted breeding, QTL.

Variation in seed glucosinolate concentrations of Indian mustard (Brassica juncea (L.) Czern. + Coss.)

Detailed analysis of the seeds of 128 individual plants of an Indian mustard accession, PI 183117, grown at a field site with adequate soil sulfur, revealed a wide variation in both the composition and total concentrations of seed glucosinolates. An apparent somaclonal variant of the same accession is also reported. Selection of seeds from this variant resulted in the isolation of plants with significantly lower seed glucosinolate levels and a greatly reduced variability in both content and proportions of the major seed glucosinolates, compared with the parental line. Averaged over the field experiment, and 2 glasshouse experiments (the second with 2 soil sulfur levels), the reduction in total glucosinolate concentration was 22%. Neither the effect of additional sulfur, nor its interaction with the test populations, was significant. Assuming that the variation in total seed glucosinolate concentration between plants within the selection was entirely environmental, the lower limit of the broad sense heritability in the original accession was estimated as 29.5%. Additional genetic variation appears to be necessary to reduce the seed glucosinolate content to the maximum level specified under the 'Canola' standard for rapeseed.