S02 - Session O5 - Resistance of Brassica L. vegetable crops to Lepidoptera insects due to the content of biologically active substances

Authors: Anna Artemyeva *, Anastasia Kurina, Alla Solovieva, Franziska Hanschen, Katja Witzel

In the context of widespread expansion of leaf-eating pests on Brassica crops with requirements of environmental protection, knowledge of botanical, ecological-geographical, and biochemical patterns of plant resistance to insects is necessary. The purpose of the present work is to study the variability of the content of biologically active phenolic compounds, chlorophyll and carotenoid pigments and glucosinolates and the degree of Brassica L. vegetable crops resistance to the generalized pest cabbage scoop Mamestra brassicae and the specialized pest cabbage moth Plutella xylostella . The material included 100 Brassica rapa L. accessions, a representative part of the Russian (VIR) worldwide collection, including more than 1600 accessions n Chinese cabbage, pakchoi, tatsoi, wutacai, mizuna, leafy and root turnip. The study of the degree of resistance to damage by pests in natural and artificial conditions was carried out in three ecological zones of the Russian Federation: the Far North, North-West, and the Southern. Here, it was revealed that both leaf-eating insects are most harmful in the Southern zone of Russia, the cabbage moth is a constant pest in the North-West and the Far North. A high level of congruence between natural and artificial infection conditions was determined. High variability of resistance of B. rapa crops to insects was observed - from full susceptibility to resistance. The botanical confinement of resistance among crops and types of cultivars has been determined - mainly among semi-headed cultivars of Chinese cabbage, Russian and Scandinavian cultivars of root turnip. Sources of complex resistance to insects are identified. Highly susceptible plants to cabbage scoop accessions belong mainly to crops and cultivar types with a high content of biologically active compounds. Direct correlations of a medium degree (0.53-0.54) were established between the degree of damage to cabbage scoop and the content of chlorophylls and carotenoids, while there are no such correlations between the degrees of damage to cabbage moth. Apparently, resistance to cabbage moth is connected only to the content of specific plant components with protective properties. This research will reveal new patterns of plant-pest interaction. Funding: The reported study was funded by Russian Foundation of Fundamental Researches (RFFR) and German Research Foundation (DFG), project number 21-516-12001 Functional analysis of glucosinolate breakdown products in herbivory resistance of Brassica rapa L.