A new species of functionally dioecious bush tomato of SolanumsubgenusLeptostemonum is described. Martine & T.M.
View Article and Find Full Text PDFOenothera sect. Calylophus is a North American group of 13 recognized taxa in the evening primrose family (Onagraceae) with an evolutionary history that may include independent origins of bee pollination, edaphic endemism, and permanent translocation heterozygosity. Like other groups that radiated relatively recently and rapidly, taxon boundaries within Oenothera sect.
View Article and Find Full Text PDFPremise: Evolutionary studies require solid phylogenetic frameworks, but increased volumes of phylogenomic data have revealed incongruent topologies among gene trees in many organisms both between and within genomes. Some of these incongruences indicate polytomies that may remain impossible to resolve. Here we investigate the degree of gene-tree discordance in Solanum, one of the largest flowering plant genera that includes the cultivated potato, tomato, and eggplant, as well as 24 minor crop plants.
View Article and Find Full Text PDFPremise: Five to six percent of angiosperm species exhibit a dioecious sexual system, with unisexual "male" or "female" flowers borne on separate plants. The consequent need for inter-individual pollen exchange is a special challenge for taxa where pollen is the sole pollinator reward. Dioecious Australian Solanum assure visits from pollen-foraging bees via production of inaperturate pollen in functionally female (morphologically bisexual) flowers.
View Article and Find Full Text PDFPremise: Divergence depends on the strength of selection and frequency of gene flow between taxa, while reproductive isolation relies on mating barriers and geographic distance. Less is known about how these processes interact at early stages of speciation. Here, we compared population-level differentiation in floral phenotype and genetic sequence variation among recently diverged Castilleja to explore patterns of diversification under different scenarios of reproductive isolation.
View Article and Find Full Text PDFA bush tomato that has evaded classification by solanologists for decades has been identified and is described as a new species belonging to the Australian " group" of the Ord Victoria Plain biogeographic region in the monsoon tropics of the Northern Territory. Although now recognised to be andromonoecious, Martine & McDonnell, exhibits multiple reproductive phenotypes, with solitary perfect flowers, a few staminate flowers or with cymes composed of a basal hermaphrodite and an extended rachis of several to many staminate flowers. When in fruit, the distal rachis may abcise and drop.
View Article and Find Full Text PDFThe dioecious and andromonoecious Solanum taxa (the "S. dioicum group") of the Australian Monsoon Tropics have been the subject of phylogenetic and taxonomic study for decades, yet much of their basic biology is still unknown. This is especially true for plant-animal interactions, including the influence of fruit form and calyx morphology on seed dispersal.
View Article and Find Full Text PDFPremise Of The Study: We provide the largest phylogenetic analyses to date of Apocynaceae in terms of taxa and molecular data as a framework for analyzing the evolution of vegetative and reproductive traits.
Methods: We produced maximum-likelihood phylogenies of Apocynaceae using 21 plastid loci sampled from 1045 species (nearly 25% of the family) and complete plastomes from 73 species. We reconstructed ancestral states and used model comparisons in a likelihood framework to analyze character evolution across Apocynaceae.
Premise Of The Study: Hyb-Seq, the combination of target enrichment and genome skimming, allows simultaneous data collection for low-copy nuclear genes and high-copy genomic targets for plant systematics and evolution studies. •
Methods And Results: Genome and transcriptome assemblies for milkweed (Asclepias syriaca) were used to design enrichment probes for 3385 exons from 768 genes (>1.6 Mbp) followed by Illumina sequencing of enriched libraries.