Herbivory plays a significant role in shaping plant-insect interactions. In this study, we investigated the relationship between leaf color and insect herbivory in the cannonball trees Lecythis pisonis. We focused on the temporal patterns of herbivory and leaf defense, taking into account the changes in leaf color throughout the season. Our findings revealed that young pink leaves exhibited smaller leaf area and greater specific leaf area (SLA) compared to green leaves. This higher SLA indicates that young pink leaves may be more susceptible to herbivory due to lower physical defense. However, despite these differences, there was no significant effect of leaf color on herbivory levels in the month of bud burst. This finding suggests that during the early stages of ontogeny, L. pysonis leaves do not suffer significant herbivory, which may indicate that their coloration acts as a deterrent to herbivore attack. Throughout the rainy season, no significant differences were found in herbivory, with an average of 4.5% of leaf area removed and 9.3% frequency of leaves attacked. While our results indicate a lack of significant differences in herbivory between pink and green leaves the increase in the number of attacked leaves following the change in leaf coloration suggests an increase in herbivore activity over the season. This study provides insights into the complex dynamics of herbivory and leaf coloration in cannonball trees and highlights the need for further research to elucidate the relationship between leaf pigments and levels of chemical and mechanical defense against herbivory.

In recent years, there has been a growing interest in research on Ceratozamia cycads, which has resulted in a significant increase in our understanding of their diversity. However, species complexes that have been tackled through integrative methodologies have exhibited a bias towards morphology over genealogy. Thus, there arises the necessity to reevaluate the Ceratozamia mexicana species complex using phylogeographic tools. For this purpose, we have employed the integrative taxonomic protocol Schlick-Steiner et al. (2010) put forth. This protocol delineates species as testable hypotheses, incorporating lines of evidence within a reproducible and falsifiable framework. The evaluated data encompassed (i) phylogenetic and molecular variance analyses, (ii) multivariate morphometric analyses, and (iii) analysis of climatic niches. Out of the 196 individuals from 13 studied populations, seven monophyletic groups were recovered. These groups were substantiated by multivariate morphometric analysis, revealing significant differences, and were further validated by niche divergence. These results underscore a ‘whole agreement’ across the three disciplines, thus providing robust support for acknowledging the species as distinct lineages. The species delimited by these lineages, encompassing phylogenetic, morphological, and environmental factors, correspond to C. brevifrons, C. delucana, C. decumbens, C. mexicana, C. moretti, C. tenuis, and a novel cryptic species, sister to the latter. Finally, this genealogical characterization will offer utility in the future for uncovering the genetic identity of the holotype of the type species within the Ceratozamia genus.

Ecotypic divergence in tree taxa often occurs in sub-alpine habitats, where environmental conditions are more stressful than those in lower elevations. In the mountain oak species in Japan, Quercus crispula (Qc), the sub-alpine shrubby variety, Q. crispula var. horikawae (Qch), has been recognized in central and northern Honshu. Although Qch has different phenotypes from Qc, genetic divergence between Qc and Qch has not been examined yet. Pairs of Qc and Qch populations in eight locations and additional Qc and Qch populations around these locations were investigated. Leaf size of Qch was smaller than that of Qc. Chloroplast DNA haplotypes were shared between the Qc and Qch populations. In genotypes at 29 nuclear microsatellite loci, genetic diversity did not differ between the Qc and Qch populations. Principal component analysis and a neighbor-joining tree of populations based on microsatellite genotypes demonstrated that 13 Qc populations and eight Qch populations were grouped separately, except for three Qch populations that were grouped to Qc. Climatic conditions in the eight Qch populations were characterized by lower temperature and heavier snowfall than those in the 16 populations of the genetic group of Qc. These results suggest the genetic divergence between Qc and Qch associated with sub-alpine climatic conditions, irrespective of leaf size. The origin of the sub-alpine Qch lineage and the history of ecotypic divergence should be investigated in future genomic studies.

Adaptive introgression has been proposed in oaks (genus Quercus). In northern Japan, Q. mongolica var. crispula (Qc) is common in inland habitats, and Q. dentata (Qd) occurs in coastal habitats. At the northern distributional limit of Qd, Q. × angustilepidota (Qa), a hybrid taxon between Qc and Qd, occurs in coastal habitats. The three taxa, Qc, Qa, and Qd, were transplanted to inland and coastal common gardens (sites). Genotypes at 27495 loci, phenotypes of eight traits of leaves and shoots, and 30-year-old tree size were measured for 224 individuals in both sites. Genotypic variation revealed a hybrid zone between Qc and Qd, including both northern-edge Qd admixed with Qc and coastal Qa backcrossed to Qc. Phenotypes of Qa trees were intermediate between those of Qc and Qd trees. Size of Qa and Qd trees was smaller than that of Qc trees in the inland site but was larger in the coastal site, suggesting adaptation of Qa and Qd to coastal environment. Local ancestry was estimated from phased genotypes of admixed trees using reference genotypes of 47 Qc and 25 Qd trees, indicating heterogeneous ancestry along chromosomes. Association mapping of genotypes and admixture mapping of ancestry suggested that some loci potentially associated with four traits were related to stress response and were located at introgressed genomic regions. Further studies are necessary to show the genetic basis of adaptive introgression resulting in Qd-like phenotypes of Qa in coastal habitats.

Tetraploid Ficaria verna is a common spring geophyte that forms large populations in central Europe and is considered invasive in northern USA and Canada. It is considered an almost seed-sterile taxon, relying on vegetative reproduction by underground tubers and aerial bulbils. Recent studies have revealed high levels of population genetic diversity in F. verna, raising the question of how genetic diversity is maintained and which factors may be responsible for the observed patterns. Polymorphic nuclear microsatellite markers were established to define multi-locus genotypes (MLGs), to analyze fine-scale spatial genetic structure (SGS) using grid and cross sampling schemes, and to quantify genetic diversity within and between nine populations with different disturbance regimes in central Germany. 115 MLGs were identified among a total of 347 samples. The G/N ratio varied between 0.16 and 0.70 among populations, and in each population a number of unique MLGs occurred. Genotypes were highly intermingled within populations, suggesting a ‘guerrilla’ dispersal strategy. Significant negative SGS was found in five out of nine populations in fine-scale cross sampling (up to 4 m) and in only one population in grid sampling (up to 14.6 m). No single MLG was found in more than one population, while many alleles were shared between populations. Within-population genetic diversity increased with greater exposure to both anthropogenic and natural disturbances. Regular gap openings, facilitated propagule establishment (vegetative and sexual), and propagule dispersal by water and mowing machines are likely important factors explaining the positive effects of disturbance on local genetic diversity of F. verna.