PREMISE During plant domestication, traits can be subject to a variety of types of selection, ranging from strong directional selection for traits such as seed or fruit size to diversifying selection for traits like color or flavor. These types of selection interact with other evolutionary processes including genetic bottlenecks and interspecific gene flow to generate different levels of genetic diversity across the genome and at target genes in domesticated lineages, but little is known about the impacts of these processes in perennial fruit crops. METHODS We used sequence capture by hybridization to examine patterns of diversity at a suite of candidate domestication and anonymous background genes in domesticated apple (Malus ×domestica) in comparison to its wild relatives Malus sieversii and Malus orientalis. RESULTS We found no change in average diversity at these candidate domestication genes across the three species. However, a subset of the genes did exhibit patterns of very high or very low diversity in M. ×domestica compared to its progenitor, M. sieversii. Of the genes with characterized function, the low-diversity genes mainly contributed to fruit quality traits like color and flavor, predicted to be under conscious, directional selection relatively late in the domestication process, while the high-diversity genes included a variety of functions. CONCLUSIONS Overall, these results are consistent with predictions based on the likely timing and nature of selection during domestication and open new avenues for understanding genes with high diversity in a perennial crop compared to its wild relatives.

Premise Cornales is an order of flowering plants containing ecologically and horticulturally important families, including Cornaceae (dogwoods) and Hydrangeaceae (hydrangeas), among others. While many relationships in Cornales are strongly supported by previous studies, some uncertainty remains with regards to the placement of Hydrostachyaceae and to relationships among families in Cornales and within Cornaceae. Here we analyzed hundreds of nuclear loci to test published phylogenetic hypotheses and estimated a robust species tree for Cornales. Methods Using the Angiosperms353 probe set and existing data sets, we generated phylogenomic data for 158 samples, representing all families in the Cornales, with intensive sampling in the Cornaceae. Results We curated an average of 312 genes per sample, constructed maximum likelihood gene trees, and inferred a species tree using the summary approach implemented in ASTRAL-III, a method statistically consistent with the multispecies coalescent model. Conclusions The species tree we constructed generally shows high support values and a high degree of concordance among individual nuclear gene trees. Relationships among families are largely congruent with previous molecular studies, except for the placement of the nyssoids and the Grubbiaceae-Curtisiaceae clades. Furthermore, we were able to place Hydrostachyaceae within Cornales, and within Cornaceae, the monophyly of known morphogroups was well supported. However, patterns of gene tree discordance suggest potential ancient reticulation, gene flow, and/or ILS in the Hydrostachyaceae lineage and the early diversification of Cornus. Our findings reveal new insights into the diversification process across Cornales and demonstrate the utility of the Angiosperms353 probe set.

Heptapteridae is composed of 228 valid species allocated in 24 genera, making it the most diverse family within superfamily Pimelodoidea, a clade endemic to the Neotropical freshwaters. Heptapterids are widely distributed from southern Mexico to the Pampas of Argentina and occupy a variety of habitats generally in small- to medium-sized rivers. To evaluate the phylogenetic relationships of Heptapteridae, we used a matrix with 1,319 ultraconserved elements (UCEs) from the genome from 56 specimens spanning 42 species and 24 genera of Heptapteridae and 19 related siluriform taxa. Maximum likelihood, Bayesian and coalescent-based analyses strongly supported the monophyly of Heptapteridae and confirmed previous hypotheses of a sister relationship between Heptapteridae and Conorhynchos conirostris. We provide the evidence to recognize two subfamilies: (1) Rhamdiinae (Goeldiella, Rhamdella, Rhamdia, Brachyrhamdia, Pimelodella) and (2) Heptapterinae; with two tribes: Brachyglaniini new tribe (Gladioglanis, Myoglanis, Brachyglanis and Leptorhamdia) and Heptapterini (Mastiglanis, Chasmocranus, Cetopsorhamdia, Pariolius, Phenacorhamdia, Nemuroglanis, Imparfinis, Taunayia, Rhamdioglanis, Acentronichthys, Rhamdiopsis and Heptapterus). Inside Heptapterini, we recognize five subclades and provide putative morphological synapomorphies. This paper represents the first molecular hypothesis of intergeneric and interspecific relationships helping to better delineate heptapterid taxa.

A dataset of promoter and 5’UTR sequences of homoeo-alleles of 495 wheat genes that contribute to agriculturally important traits in 95 ancestral and commercial wheat cultivars is presented here. The high stringency myBaits technology used made individual capture of homoeo-allele promoters possible, which is reported here for the first time. Promoters of most genes are remarkably conserved across the 82 hexaploid cultivars used with <7 haplotypes per promoter and 21% being identical to the reference Chinese Spring. InDels and many high-confidence SNPs are located within predicted plant transcription factor binding sites, potentially changing gene expression. Most haplotypes found in the Watkins landraces and a few haplotypes found in T. monococcum, germplasms hitherto not thought to have been used in modern wheat breeding, are already found in many commercial hexaploid wheats. The full dataset which is useful for genomic and gene function studies and wheat breeding is available at https://rrescloud.rothamsted.ac.uk/index.php/s/3vc9QopcqYEbIUs/authenticate.