Genomic structure, introgression, niche overlap, and morphological variation challenges species delimitation in Thymus sect. Mastichina
Authors: Nieto-Lugilde, D., del Valle Garcia, J. C., Martin-Carretie, E. M., Doblas, D., Williams-Marland, B., Ortiz Herrera, M. A., Jimenez-Lopez, F. J., Lopez-Tirado, J., Garcia-Cardenas, F. J., Berjano, R.
Integrating genomic data with detailed floral morphology and ecological niche analyses, the study reveals extensive phenotypic overlap among genetically distinct diploid and tetraploid lineages of Thymus sect. Mastichina, highlighting discordance between morphology and genetic structure. While ploidy level partly drives ecological niche differentiation, most morphological variation fails to align with genetic lineages, underscoring the need for integrative taxonomic approaches for this cryptic Mediterranean group.
The authors used a bottom‑up thermodynamic modelling framework to investigate how plants decode calcium signals, starting from Ca2+ binding to EF‑hand proteins and extending to higher‑order decoding modules. They identified six universal Ca2+-decoding modules that can explain variations in calcium sensitivity among kinases and provide a theoretical basis for interpreting calcium signal amplitude and frequency in plant cells.
Eighty-eight herbarium specimens of the Galapagos mistletoe Phoradendron berteroanum were measured for eight vegetative and floral traits, and univariate and multivariate analyses were conducted across altitude, island, host, and vegetation cover. Leaf size and internode length peaked at mid‑elevations while floral segment number declined with altitude, and flower number varied with host species, but no distinct island‑specific morphotypes were detected, indicating a single species responding to local environmental conditions.