Studies on chemical ecology of host plant selection by herbivores were largely carried out to explain the diversity of secondary plant chemicals and host specialisation of herbivores. The glucosinolate – isothiocyanate system in Brassicaceae plants was considered as a plant defence and was known to influence the feeding behaviour of phytophagous insects such as the cabbage aphid, Brevicoryne br...

Clubroot disease caused by an obligate biotroph, Plasmodiophora brassicae Woronin, causes damage to cruciferous vegetables. In the breeding of Chinese cabbage (Brassica rapa L. ssp. pekinens is) in Japan, European turnips were fbund to be a source ofclubroot-resistance (CR) genes (Yoshikawa 1981). To date, more than 50 CR Fi cultivars have been bred. However, the breakdown ofthe clubroot resist...

Clubroot disease caused by Plasmodiophora brassicae is one of the most important diseases of cultivated brassicas. P. brassicae occurs in pathotypes which differ in the aggressiveness towards their Brassica host plants. To date no DNA based method to distinguish these pathotypes has been described. In 2011 polymorphism within the 28S rDNA of P. brassicae was reported which potentially could all...

Farms benefit from pest control services provided by nature, but management of these services requires an understanding of how habitat complexity within and around the farm impacts the relationship between agricultural pests and their enemies. Using cage experiments, this study measures the effect of habitat complexity across scales on pest suppression of the cabbage aphid Brevicoryne brassicae...

Host race formation in phytophagous insects can be an early stage of adaptive speciation. However, the evolution of phenotypic plasticity in host use is another possible outcome. Using a reciprocal transplant experiment we tested the hypothesis of local adaptation in the aphid Brevicoryne brassicae. Aphid genotypes derived from two sympatric host plants, Brassica oleracea and B. campestris, wer...

Release of transgenic insect-resistant crops creates the potential not only for the insect pest to evolve resistance but for the escape of transgenes that may confer novel or enhanced fitness-related traits through hybridization with their wild relatives. The differential response of diamondback moth (Plutella xylostella) populations in eastern and western Canada to Bt-producing (GT) Brassica n...

essential oils are volatile mixtures of hydrocarbons with diverse functional groups. in the current study the effect of essential oils from five medicinal plants including zataria multiflora and nepeta cataria (lamiaceae), tagetes minuta and artemisia sieberi (asteraceae), and trachyspermum ammi (apiaceae) were analyzed using gc-mass spectrometry. the toxicity of these plant essential oils agai...

A novel subclass of dehydrin genes, homologous to the Raphanus sativus late embryogenesis-abundant (LEA) protein (RsLEA2) and the Arabidopsis thaliana dehydrin, was isolated from Brassica juncea and Brassica napus, here designated BjDHN1 and BnDHN1, respectively. The cDNA of BjDHN1 and BnDHN1 genes share 100% nucleotide identity. The encoded protein is predicted to consist of 183 amino acid res...