Inheritance of vegetative characters in pepper (Capsicum annuum L.)

International audienc

Incidence and genetic diversity of cucurbit viruses in the Spanish Mediterranean area

[EN] Viral infections on cucurbits fields can cause major economic losses. Monitoring of the main producing areas is essential to identify both prevalent and emerging viruses. For two consecutive years (2019-2020), the presence and molecular diversity of 9 aphid- and whitefly-transmitted viruses in the main cucurbits producing areas of the Spanish Mediterranean basin and other important regions were studied. In analyses of symptomatic plants, watermelon mosaic virus (WMV), cucurbit aphid-borne yellows virus (CABYV) and cucumber mosaic virus (CMV) were found to be prevalent in all the monitored areas, regardless of the crop and the farming conditions. Moroccan watermelon mosaic virus (MWMV) and tomato leaf curl New Delhi virus (ToLCNDV) were also found at lower rates, mainly in mixed infections with WMV. Phylogenetic analyses were conducted to determine the molecular variability of the different isolates. Whereas the sequences of CABYV, MWMV and ToLCNDV isolates all clustered within their corresponding Mediterranean clade, new viral variants of WMV and CMV were found. Concretely, 7 new WMV profiles and a reassorting CMV isolate (IB-IB-IA) were observed. Moreover, the complete genome of the newly described WMV isolates was sequenced. Further studies should be done to determine if these new variants spread to new areas and if they can overcome the previously described resistances.Agencia Estatal de Investigacion, Grant/Award Number: PID2020-116055RB (C21 and C22) and PRE2018-083466; Generalitat Valenciana, Grant/Award Number: PROMETEO/2021/072.López-Martín, M.; Sifres Cuerda, AG.; Gómez-Guillamón, ML.; Picó Sirvent, MB.; Pérez De Castro, AM. (2024). Incidence and genetic diversity of cucurbit viruses in the Spanish Mediterranean area. Plant Pathology. 73(2):431-443. https://doi.org/10.1111/ppa.1382543144373

A Novel Introgression Line Library Derived from a Wild Melon Gives Insights into the Genetics of Melon Domestication, Uncovering New Genetic Variability Useful for Breeding

A collection of 30 melon introgression lines (ILs) was developed from the wild accession Ames 24297 (TRI) into ‘Piel de Sapo’ (PS) genetic background. Each IL carried an average of 1.4 introgressions from TRI, and the introgressions represented 91.4% of the TRI genome. Twenty-two ILs, representing 75% of the TRI genome, were evaluated in greenhouse (Algarrobo and Meliana) and field (Alcàsser) trials, mainly to study traits related to domestication syndrome such as fruit weight (FW) and flesh content (FFP), as well as other fruit quality traits as fruit shape (FS), flesh firmness (FF), soluble solid concentration (SSC), rind color and abscission layer. The IL collection showed an impressive variation in size-related traits, with FW ranging from 800 to 4100 g, reflecting the strong effect of the wild genome on these traits. Most of the ILs produced smaller fruits compared with PS; however, unexpectedly, the IL TRI05-2 produced bigger fruits, likely due to new epistatic interacions with the PS genetic background. In contrast, the genotypic effect for FS was smaller, and few QTLs with notable effects were detected. Interestingly, variability was also observed for FFP, FF and SSC, rind color and abscission layer formation. Genes in these introgressions are candidates for having been involved in melon domestication and diversification as well. These results confirm that the TRI IL collection is a very powerful tool for mapping traits of agronomic interest in melon, allowing the confirmation of previously reported QTLs and the identification of new ones to better understand the domestication process of this crop