RESUMO
Blackcurrant leaf midge (Dasineura tetensi) is a widespread pest of blackcurrant. Attacks by this pest can cause up to 60% reduction in the growth of shoots resulting in yield decreases. Our study, conducted (2012-2014) in Poland, aimed to assess the susceptibility of blackcurrant genotypes to D. tetensi, in order to select genotypes as parental lines for breeding new blackcurrant genotypes. Among tested blackcurrant genotypes, none were found to be completely resistant to this pest. The pest colonized genotypes Big Ben, Nr 8/72, Ben Connan, Ben Alder, Ben Hope, Foxendown, Ben Nevis, Fariegh, Ojebyn, and Ben Tirran below the threshold level (10%). In contrast, genotypes Nr 7/15, Ben Lomond, Ben Finlay, Tisel, Polares, Polonus, Tiben, PC-110, Polben, Gofert, Ruben, and Ores suffered pest levels above the threshold. With regard to egg numbers, the fewest were recorded on genotypes Big Ben, Ben Connan, Ben Alder, and Ben Nevis, and the most on Gofert and Ores. Fewer larvae were recorded on genotypes Big Ben, Nr 8/72, Ben Connan, and Foxendown compared to Ben Lomond, PC-110, Gofert, Tiben, Polben, and Ores. Developing blackcurrant genotype resistance to leaf midge strongly supports the IPM strategy.
RESUMO
Blackcurrant leaf midge (Dasineura tetensi) is one of the most common pests of blackcurrant (Ribes nigrum). The aim of this study was to investigate changes in the content of phenolic compounds in the leaves damaged by the larvae of this pest. Additionally, susceptibility of different blackcurrant cultivars to the midge attack was investigated. Qualitative and quantitative analyses of control and pest-infested blackcurrant leaves were performed using LC-PDA-QTOF/MS and UPLC-PDA-FL systems. A total of 39 types of phenolic compounds were identified in blackcurrant leaf extracts and they included 3 flavan-3-ols, 14 hydroxycinnamic acid derivatives, and 22 flavonols. Feeding of blackcurrant leaf midge on blackcurrant leaves lowered the content of leaf polyphenolic compounds. The greatest differences in polyphenolics between control and infected leaves were observed in 'Ruben', 'Fariegh', 'Foxendown', 'Ores', 'Ben Hope', 'Ben Connan' and 'Tisel' cultivars that were probably highly susceptible to the pest attack. In the other cultivars: 'Ben Finlay', 'Polares', 'Tiben', and 'Gofert' the differences in phenolics content were less pronounced, so they were probably less susceptible to D. tetensi attack. Plant polyphenolic compounds was strongly involved in pathogen-plant interaction, and their accumulation significantly decreased as a result of the pathogen attack.
