Phenolic compounds are a large group of phytochemicals widespread in the plant kingdom. Depending on their structure they can be classified into simple phenols, phenolic acids, hydroxycinnamic acid derivatives and flavonoids. Phenolic compounds have received considerable attention for being potentially protective factors against cancer and heart diseases, in part because of their potent antioxidative properties and their ubiquity in a wide range of commonly consumed foods of plant origin. The Brassicaceae family includes a wide range of horticultural crops, some of them with economic significance and extensively used in the diet throughout the world. The phenolic composition of Brassica vegetables has been recently investigated and, nowadays, the profile of different Brassica species is well established. Here, we review the significance of phenolic compounds as a source of beneficial compounds for human health and the influence of environmental conditions and processing mechanisms on the phenolic composition of Brassica vegetables.

We describe the construction of a reference genetic linkage map for the Brassica A genome, which will form the backbone for anchoring sequence contigs for the Multinational Brassica rapa Genome Sequencing Project. Seventy-eight doubled haploid lines derived from anther culture of the F(1) of a cross between two diverse Chinese cabbage (B. rapa ssp. pekinensis) inbred lines, 'Chiifu-401-42' (C) and 'Kenshin-402-43' (K) were used to construct the map. The map comprises a total of 556 markers, including 278 AFLP, 235 SSR, 25 RAPD and 18 ESTP, STS and CAPS markers. Ten linkage groups were identified and designated as R1-R10 through alignment and orientation using SSR markers in common with existing B. napus reference linkage maps. The total length of the linkage map was 1,182 cM with an average interval of 2.83 cM between adjacent loci. The length of linkage groups ranged from 81 to 161 cM for R04 and R06, respectively. The use of 235 SSR markers allowed us to align the A-genome chromosomes of B. napus with those of B. rapa ssp. pekinensis. The development of this map is vital to the integration of genome sequence and genetic information and will enable the international research community to share resources and data for the improvement of B. rapa and other cultivated Brassica species.

bGlucosinolates (GSLs) are secondary metabolites found in Brassica vegetables that confer on them resistance against pests and diseases. Both GSLs and glucosinolate hydrolysis products (GHPs) have shown positive effects in reducing soil pathogens. Information about their in vitro biocide effects is scarce, but previous studies have shown sinigrin GSLs and their associated allyl isothiocyanate (AITC) to be soil biocides. The objective of this work was to evaluate the biocide effects of 17 GSLs and GHPs and of leaf methanolic extracts of different GSL-enriched Brassica crops on suppressing in vitro growth of two bacterial (Xanthomonas campestris pv. campestris and Pseudomonas syringae pv. maculicola) and two fungal (Alternaria brassicae and Sclerotinia scletoriorum) Brassica pathogens. GSLs, GHPs, and methanolic leaf extracts inhibited the development of the pathogens tested compared to the control, and the effect was dose dependent. Furthermore, the biocide effects of the different compounds studied were dependent on the species and race of the pathogen. These results indicate that GSLs and their GHPs, as well as extracts of different Brassica species, have potential to inhibit pathogen growth and offer new opportunities to study the use of Brassica crops in biofumigation for the control of multiple diseases.T he genus Brassica belongs to the family Brassicaceae (also known as Cruciferae); economically speaking, it is the most important genus within the tribe Brassicaceae, containing 37 different species. Brassica vegetables are of great economic importance throughout the world. Currently, Brassica crops, together with cereals, represent the basis of world food supplies. In 2007, Brassica vegetables were cultivated in more than 142 countries around the world, and they occupied more than 4.1 million ha (1).The productivity and quality of important Brassica crops (e.g., cabbage, oilseed rape, cauliflower, Brussels sprouts, kale, and broccoli) are seriously affected by several diseases, which result in substantial economic losses (2). Black rot, caused by the bacterium Xanthomonas campestris pv. campestris (Pammel), is considered to be one of the most important pathogens affecting Brassica vegetables worldwide (3). There are nine races of Xanthomonas campestris pv. campestris: races 1 to 6 were described by Vicente et al. (4) and races 7 to 9 by Fargier and Manceau (5). It is recognized that races 1 and 4 are the most virulent and widespread, accounting for most of the black rot recorded around the world (4).Bacterial leaf spot, caused by Pseudomonas syringae pv. maculicola (McCulloch) (6), is very significant on cauliflower but also occurs on broccoli, Brussels sprouts, and other brassicas. P. syringae pv. maculicola may also cause leaf blight on the oilseed species Brassica juncea and Brassica rapa (3).Sclerotinia stem rot, caused by Sclerotinia sclerotiorum (Lib.) de Bary, is a widespread fungal disease in temperate areas of the world and also occurs in warmer and drier areas during the winter months or the rain...

BackgroundDue to its biennual life cycle Brassica oleracea is especially exposed to seasonal changes in temperature that could limit its growth and fitness. Thermal stress could limit plant growth, leaf development and photosynthesis. We evaluated the performance of two local populations of B. oleracea: one population of cabbage (B. oleracea capitata group) and one population of kale (B. oleracea acephala group) under limiting low and high temperatures.ResultsThere were differences between crops and how they responded to high and low temperature stress. Low temperatures especially affect photosynthesis and fresh weight. Stomatal conductance and the leaf water content were dramatically reduced and plants produce smaller and thicker leaves. Under high temperatures there was a reduction of the weight that could be associated to a general impairment of the photosynthetic activity.ConclusionsAlthough high temperatures significantly reduced the dry weight of seedlings, in general terms, low temperature had a higher impact in B. oleracea physiology than high temperature. Interestingly, our results suggest that the capitata population is less sensitive to changes in air temperature than the acephala population.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-015-0535-0) contains supplementary material, which is available to authorized users.