Temporal and species-specific resistance of sugar beet to green peach aphid and black bean aphid: mechanisms and implications for breeding

BACKGROUNDSugar beet (Beta vulgaris ssp. vulgaris), a key crop for sugar production, faces significant yield losses caused by the black bean aphid Aphis fabae (Scop.) and the green peach aphid Myzus persicae (Sulzer), which also transmits viruses. The restriction on neonicotinoid usage in Europe has intensified this problem, emphasizing the urgent need for breeding resistant crop varieties. This study evaluated 26 sugar beet germplasms for resistance against both aphid species by using performance and feeding behavior assays. Additionally, whole plant bioassays and semi-field experiments were carried out with Myzus persicae.RESULTSOur findings demonstrate the presence of temporal resistance against both aphid species in the primary sugar beet gene pool. Beet yellows virus (BYV) carrying aphids showed enhanced performance. Different levels of plant defense mechanisms were involved including resistance against Myzus persicae before reaching the phloem, particularly in sugar beet line G3. In contrast, resistance against Aphis fabae turned out to be predominately phloem-located. Furthermore, a high incidence of black inclusion bodies inside the stomach of Myzus persicae was observed for approximately 85% of the plant genotypes tested, indicating a general and strong incompatibility between sugar beet and Myzus persicae in an initial phase of interaction.CONCLUSIONSugar beet resistance against aphids involved different mechanisms and is species-specific. The identification of these mechanisms and interactions represents a crucial milestone in advancing the breeding of sugar beet varieties with improved resistance. (c) 2023 Julius Kuhn-Institut and The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. Temporal and tissue-specific (Myzus persicae before reaching the phloem, and Aphis fabae in the phloem) resistance were found on sugar beet against two major aphid species during initial infestation phase. Strong incompatibility was indicated by high incidence of black stomach formation, carrying beet yellows virus (BYV), and host adaptation enhanced long-term aphid population development.image