An analysis of morphometric and bionomic data (as well as the genetic evidence discussed in a companion paper) clearly shows that Meligethes matronalis Audisio & Spornraft, 1990 and M. subaeneus Sturm, 1845 (members of the Meligethes coracinus complex: Coleoptera, Nitidulidae, Meligethinae), recently synonymised by Kirejtshuk (1997), are distinct species. The two species are also compared with the closely related M. coracinus Sturm, 1845. Meligethes matronalis is strictly associated with Hesperis matronalis L. (Brassicaceae) in early Summer, whereas the larvae of the frequently syntopic M. subaeneus develop on Cardamine spp. (Brassicaceae) in Spring; M. coracinus is a more polyphagous species, developing from early Spring to late Summer mostly on Brassica spp., Sinapis spp., Barbarea spp. and Sisymbrium spp. (Brassicaceae).

A particular small size has made the Arabidopsis thaliana genome the best-studied genome of a higher plant. Comparative genetic mapping experiments have established colinearity of genomes for species of the Brassicaceae family. More recently physical mapping and sequencing experiments established conservation of gene order. Patterns of genome colinearity that have been discovered to date will be described. One of the prime goals of comparative genome studies is the exploitation of information that has been assembled for model species with small genomes for the analysis of related plants with complex genomes. Specifically, the prospects for correlating traits in the Brassica crops with Arabidopsis candidate genes will be discussed

peer reviewed | Three Brassicaceae species, Brassica napus (low glucosinolate content), Brassica nigra (including sinigrin), and Sinapis alba (including sinalbin) were used as host plants for two aphid species: the generalist Myzus persicae and the specialist Brevicoryne brassicae. Each combination of aphid species and prey host plant was used to Feed the polyphagous ladybird beetle, Adalia bipunctata. Experiments with Brassicaceae species including different amounts and kinds of glucosinolates (GLS) showed increased ladybird larval mortality at higher GLS concentrations. When reared on plants with higher GLS concentrations, the specialist aphid, B. brassicae, was found to be more toxic than M. persicae. Identification of GLS and related degradation products, mainly isothiocyanates (ITC), was investigated in the first two trophic levels, plant and aphid species, by high-performance liquid chromatography and gas chromatography-mass spectrometry, respectively. While only GLS were detected in M. persicae on each Brassicaceae species, high amounts of ITC were identified in B. brassicae samples (allyl-ITC and benzyl-ITC from B. nigra and S. alba, respectively) from all host plants. Biological effects of allelochemicals from plants on predators through aphid prey are discussed in relation to aphid species to emphasize the role of the crop plant in integrated pest management in terms of biological control efficacy.

peer reviewed | Secondary plant substances, also called allelochemicals, play a major role in pest infestations. Glucosinolates (GLS) and their degradation products are powerful phagostimulants for herbivores feeding on Brassicaceae and deter the noncrucifer feeders but are tolerated by some generalist phytophagous insects such as the peach-potato aphid, Myzυs persicas Sultzer. Do the allelochemical substances only effect the herbivores or do they also influence the predators of the pest? Broad bean, Viciafaba L (GLS free), oilseed rape, Brassica tiapus L (low GLS level), and white mustard, Sinajris alba L. (high GLS level), were used in this work as host plant for the prey. Although the two latter Brassicaceae species had positive effects on aphid reproductive rates, host plants displayed mixed influences on the performance of the predaceous twospotted lady beetle, Adalia bipunctata L. Both rape and mustard shortened development duration and increased adult weight of the twospotted lady beetle. No significant difference of lady beetle mortality was observed, depending on the prey host plant. Whereas, rape-fed M. persicae enhanced larger egg production and larvae emergence, mustard-fed M.. persicae induced lower fecundity and egg viability of the beetles. Fitness of M. persicae on high GLS plant-fed A. bipunctata was lower than the other plants. Biological parameters of aphid predators are closely linked to chemical composition of Brassicaceae species. This work on allelochemical impact gave opportunities to better understand interactions of the plant-aphid-lady beetle tritrophic model and demonstrated that successful biological control of pests must integrate the environmental aspects of each trophic level.

Glucosinolates, natural compounds found in Brassicaceae, can easily be transformed into desulfo-glucosinolates by action of of Helix pomatia sulfatase. The recombinant beta-O-glucosidase from Caldocellum saccarolyticum does not catalyse glucosinolate degradation but can hydrolyse desulfo-glucosinolates (thio-D-glucosidicsubstrates) to produce the corresponding pure nitriles, including valuable homochiral representatives.

Scanning electron microscopy and x-ray microanalysis were used to study the localization of nickel in seeds of the hyperaccumulating species Thlaspi pindicum Hausskn. (Brassicaceae). The metal was preferentially accumulated in the micropylar area opposite the radicle and in the epidermis of cotyledons. In seed sections, nickel was detected only in the embryo epidermis. Possible reasons for this characteristic distribution are discussed.

This survey was conductednat the Qazvin province and was carried out in the 3 years . over 200 species of native medicinal plants were collected based . on existing references and local observations. The mostr identified plants were laminaceae (24 species) Asteraceae (21 species) , Rosaceae (20 species), Papilionuceae (lO species), Brassicaceae (8 species) . phytochemical stu ding of similar medicinal plants is recommended

Arabis holboellii is a North American member of the Brassicaceae that can reproduce via sex or apomixis. Previous studies have shown sexual individuals to be diploid, whilst apomictic individuals can be diploid (and aneuploid) or polyploid (typically 3x). Apomictic individuals can furthermore be facultative (i.e. both sexual and apomictic seed production in a single individual). Using flow cytometry, ploidy variation in 245 accessions of A. holboellii and A. drummondii from western North America and Greenland has been examined. Additionally, the chloroplast trnL intron region from each accession was sequenced for phylogenetic analysis of ploidy variation. Based upon 17 informative single nucleotide and insertion-deletion polymorphisms, we identified seven and 14 chloroplast haplotypes for A. drummondii and A. holboellii, respectively. Six of the haplotypes were found in both species. Ten of the chloroplast haplotypes were characterized by diploid, aneuploid, and triploid individuals, and thus we conclude that polyploidy has repeatedly and independently arisen within the species complex. As triploid individuals, which undergo normal meiosis, can only reproduce through apomixis, this may imply that the phenotype apomixis has also arisen multiple times. Arabis holboellii thus appears to have some predisposition to evolve apomictic reproduction.

Glutathione S-transferases (GST) play an important role in the detoxification of many substances including allelochemicals from plants. Brassicaceae plants contain glucosinolates and emit volatile isothiocyanates which affect the GST system. A comparison of the GST of two aphid species, the generalist Aulacorthum solani found on Brassicaceae and the Fabaceae specialist Acyrthosiphon pisum, was made to try to explain their respective feeding behaviour. Differences of GST were determined among the two aphid species based on purification by affinity chromatography, SDS-PAGE and on kinetic studies. Purification yields using an epoxy-activated Sepharose 6B column were highly different for the two aphid species (18% and 34% for A. solani and A. pisum, respectively). These variations were confirmed by SDS-PAGE. While only a 27-kDa band was observed for A. pisum, two bands of approximately 25-kDa were visualized for the generalist aphid, A. solani. Considering the kinetic results, differences of K(m) and V(max) were observed following the aphid species when a range of substrates (CDNB and DCNB) and GSH concentrations were tested. Studies on the detoxification enzymes of generalist and specialist herbivores would be undertaken to determine accurately the effect of the host plant on the organisms eating them, particularly in terms of biochemical and ecological advantages.