Distributions, conservation status, and abiotic stress tolerance potential of wild cucurbits (Cucurbita L.)

Societal Impact Statement Crop wild relatives—wild species closely related to cultivated plants—are valuable genetic resources for crop improvement, but gaps in knowledge constrain their conservation and limit their further use. We develop new information on the distributions, potential breeding value, and conservation status of the 16 known wild relatives of cultivated pumpkins, squashes, zucchini, and gourds (Cucurbita L.). The taxa occur from the central USA to Central America, plus two South American species, with the greatest richness in central Mexico and the western borderlands between Mexico and the USA. We determine the majority of species are of medium priority for conservation, both with regard to collecting for ex situ maintenance, and for enhanced habitat protection. Summary Crop wild relatives are valuable genetic resources for crop improvement. Knowledge gaps, including with regard to taxonomy, distributions, and characterization for traits of interest constrain their use in plant breeding. These deficiencies also affect conservation planning, both with regard to in situ habitat protection, and further collection of novel diversity for ex situ maintenance. Here we model the potential ranges of all 16 known wild cucurbit taxa (Cucurbita L.), use ecogeographic information to infer their potential adaptations to abiotic stresses, and assess their ex situ and in situ conservation status. The taxa occur from the central USA to Central America, plus two South American species. Predicted taxon richness was highest in central Mexico and in the western borderlands between Mexico and the USA. We find substantial ecogeographic variation both across taxa and among populations within taxa, with regard to low temperatures, high and low precipitation, and other adaptations of potential interest for crop breeding. We categorize 13 of the taxa medium priority for further conservation as a combination of the ex situ and in situ assessments, two low priority, and one sufficiently conserved. Further action across the distributions of the taxa, with emphasis on taxonomic richness hotspots, is needed to comprehensively conserve wild Cucurbita populations

Historical changes in bird communities at Quitobaquito Springs, Arizona and impacts of climate, spring flow, and shift from Indigenous to federal-agency management

For nearly a century, bird communities at the oasis of Quitobaquito Springs in the Sonoran Desert have attracted desert ecologists. This spring-fed oasis is among the most biologically and culturally significant sites in arid southwestern North America, but has experienced marked changes in management and is threatened by climate change, border, and other development. We assembled data on birds at Quitobaquito across 83 years (1939–2022) and evaluated the patterns and potential drivers of changes in communities. We found evidence of marked community shifts that included apparent loss and replacement of species dependent on riparian and wetland vegetation, mud flats, agricultural fields, and human settlements, to species that use deeper more open-water environments, generalists, and desertscrub. Strong associations between community composition and shift from Indigenous to federal-agency management, temperature, and spring flow suggest important drivers of change, but associations with precipitation and border development were weaker. Such patterns match those for bird communities at broader scales in nearby and other aridlands and indicate impacts of increasing aridification. Our work represents the first analysis of changes in faunal assemblages at Quitobaquito that quantitatively assesses potential drivers of change, and provides insights for management and conservation.24 month embargo; first published 12 October 2023This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Shifts in Plant Chemical Defenses of Chile Pepper (Capsicum annuum L.) Due to Domestication in Mesoamerica

We propose that comparisons of wild and domesticated Capsicum species can serve as a model system for elucidating how crop domestication influences biotic and abiotic interactions mediated by plant chemical defenses. Perhaps no set of secondary metabolites (SMs) used for plant defenses and human health have been better studied in the wild and in milpa agro-habitats than those found in Capsicum species. However, very few scientific studies on SM variation have been conducted in both the domesticated landraces of chile peppers and in their wild relatives in the Neotropics. In particular, capsaicinoids in Capsicum fruits and on their seeds differ in the specificity of their ecological effects from broad-spectrum toxins in other members of the Solanaceae. They do so in a manner that mediates specific ecological interactions with a variety of sympatric Neotropical vertebrates, invertebrates, nurse plants and microbes. Specifically, capsaicin is a secondary metabolite (SM) in the placental tissues of the chile fruit that mediates interactions with seed dispersers such as birds, and with seed predators, ranging from fungi to insects and rodents. As with other Solanaceae, a wide range of SMs in Capsicum spp. function to ecologically mediate the effects of a variety of biotic and abiotic stresses on wild chile peppers in certain tropical and subtropical habitats. However, species in the genus Capsicum are the only ones found within any solanaceous genus that utilize capsaicinoids as their primary means of chemical defense. We demonstrate how exploring in tandem the evolutionary ecology and the ethnobotany of human-chile interactions can generate and test novel hypotheses with regard to how the domestication process shifts plant chemical defense strategies in a variety of tropical crops. To do so, we draw upon recent advances regarding the chemical ecology of a number of wild Capsicum species found in the Neotropics. We articulate three hypotheses regarding the ways in which incipient domestication through “balancing selection” in wild Capsicum annuum populations may have led to the release of selective biotic and abiotic pressures. We then analyze which shifts under cultivation generated the emergence of Capsicum chemotypes, morphotypes and ecotypes not found in high frequencies in the wild. We hypothesize that this “competitive release” can lead to a diversification of the domesticate's investment in a greater diversity of SM potency across different cultural uses, cropping systems and ecogeographic regions. While most studies of plant domestication processes focus on morphological changes that confer greater utility or productivity in human-managed environments, we conclude that changes in the chemical ecology of a useful plant can be of paramount importance to their cultivators. The genus Capsicum can therefore provide an unprecedented opportunity to compare the roles of SMs in wild plants grown in natural Neotropical ecosystems with their domesticated relatives in the milpa agro-ecosystems of Mesoamerica. Even with the current depth of knowledge available for crop species in the genus Capsicum and Solanum, our understanding of how particular SMs affect the reproduction and survival of wild vs. domesticated solanaceous plants remains in its infancy

Table1_Shifts in Plant Chemical Defenses of Chile Pepper (Capsicum annuum L.) Due to Domestication in Mesoamerica.docx

<p>We propose that comparisons of wild and domesticated Capsicum species can serve as a model system for elucidating how crop domestication influences biotic and abiotic interactions mediated by plant chemical defenses. Perhaps no set of secondary metabolites (SMs) used for plant defenses and human health have been better studied in the wild and in milpa agro-habitats than those found in Capsicum species. However, very few scientific studies on SM variation have been conducted in both the domesticated landraces of chile peppers and in their wild relatives in the Neotropics. In particular, capsaicinoids in Capsicum fruits and on their seeds differ in the specificity of their ecological effects from broad-spectrum toxins in other members of the Solanaceae. They do so in a manner that mediates specific ecological interactions with a variety of sympatric Neotropical vertebrates, invertebrates, nurse plants and microbes. Specifically, capsaicin is a secondary metabolite (SM) in the placental tissues of the chile fruit that mediates interactions with seed dispersers such as birds, and with seed predators, ranging from fungi to insects and rodents. As with other Solanaceae, a wide range of SMs in Capsicum spp. function to ecologically mediate the effects of a variety of biotic and abiotic stresses on wild chile peppers in certain tropical and subtropical habitats. However, species in the genus Capsicum are the only ones found within any solanaceous genus that utilize capsaicinoids as their primary means of chemical defense. We demonstrate how exploring in tandem the evolutionary ecology and the ethnobotany of human-chile interactions can generate and test novel hypotheses with regard to how the domestication process shifts plant chemical defense strategies in a variety of tropical crops. To do so, we draw upon recent advances regarding the chemical ecology of a number of wild Capsicum species found in the Neotropics. We articulate three hypotheses regarding the ways in which incipient domestication through “balancing selection” in wild Capsicum annuum populations may have led to the release of selective biotic and abiotic pressures. We then analyze which shifts under cultivation generated the emergence of Capsicum chemotypes, morphotypes and ecotypes not found in high frequencies in the wild. We hypothesize that this “competitive release” can lead to a diversification of the domesticate's investment in a greater diversity of SM potency across different cultural uses, cropping systems and ecogeographic regions. While most studies of plant domestication processes focus on morphological changes that confer greater utility or productivity in human-managed environments, we conclude that changes in the chemical ecology of a useful plant can be of paramount importance to their cultivators. The genus Capsicum can therefore provide an unprecedented opportunity to compare the roles of SMs in wild plants grown in natural Neotropical ecosystems with their domesticated relatives in the milpa agro-ecosystems of Mesoamerica. Even with the current depth of knowledge available for crop species in the genus Capsicum and Solanum, our understanding of how particular SMs affect the reproduction and survival of wild vs. domesticated solanaceous plants remains in its infancy.</p

Table2_Shifts in Plant Chemical Defenses of Chile Pepper (Capsicum annuum L.) Due to Domestication in Mesoamerica.docx

<p>We propose that comparisons of wild and domesticated Capsicum species can serve as a model system for elucidating how crop domestication influences biotic and abiotic interactions mediated by plant chemical defenses. Perhaps no set of secondary metabolites (SMs) used for plant defenses and human health have been better studied in the wild and in milpa agro-habitats than those found in Capsicum species. However, very few scientific studies on SM variation have been conducted in both the domesticated landraces of chile peppers and in their wild relatives in the Neotropics. In particular, capsaicinoids in Capsicum fruits and on their seeds differ in the specificity of their ecological effects from broad-spectrum toxins in other members of the Solanaceae. They do so in a manner that mediates specific ecological interactions with a variety of sympatric Neotropical vertebrates, invertebrates, nurse plants and microbes. Specifically, capsaicin is a secondary metabolite (SM) in the placental tissues of the chile fruit that mediates interactions with seed dispersers such as birds, and with seed predators, ranging from fungi to insects and rodents. As with other Solanaceae, a wide range of SMs in Capsicum spp. function to ecologically mediate the effects of a variety of biotic and abiotic stresses on wild chile peppers in certain tropical and subtropical habitats. However, species in the genus Capsicum are the only ones found within any solanaceous genus that utilize capsaicinoids as their primary means of chemical defense. We demonstrate how exploring in tandem the evolutionary ecology and the ethnobotany of human-chile interactions can generate and test novel hypotheses with regard to how the domestication process shifts plant chemical defense strategies in a variety of tropical crops. To do so, we draw upon recent advances regarding the chemical ecology of a number of wild Capsicum species found in the Neotropics. We articulate three hypotheses regarding the ways in which incipient domestication through “balancing selection” in wild Capsicum annuum populations may have led to the release of selective biotic and abiotic pressures. We then analyze which shifts under cultivation generated the emergence of Capsicum chemotypes, morphotypes and ecotypes not found in high frequencies in the wild. We hypothesize that this “competitive release” can lead to a diversification of the domesticate's investment in a greater diversity of SM potency across different cultural uses, cropping systems and ecogeographic regions. While most studies of plant domestication processes focus on morphological changes that confer greater utility or productivity in human-managed environments, we conclude that changes in the chemical ecology of a useful plant can be of paramount importance to their cultivators. The genus Capsicum can therefore provide an unprecedented opportunity to compare the roles of SMs in wild plants grown in natural Neotropical ecosystems with their domesticated relatives in the milpa agro-ecosystems of Mesoamerica. Even with the current depth of knowledge available for crop species in the genus Capsicum and Solanum, our understanding of how particular SMs affect the reproduction and survival of wild vs. domesticated solanaceous plants remains in its infancy.</p

Beef and Beyond: Paying for Ecosystem Services on Western US Rangelands

The Rangelands archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform March 202

Effect of instrumentation systems on endotoxin reduction from root canal systems: a systematic review of clinical studies and meta-analysis

This systematic review assessed the effect of different root canal instrumentation systems on endotoxin reduction from the root canal system. The literature search was conducted in two electronic databases (PubMed and Scopus) using specific key words. The search strategy followed the PRISMA guidelines. Qualitative synthesis and quantitative synthesis of the data were performed and data interpretation was done based on the guidelines in the Cochrane Handbook. The risk of bias was assessed using Cochrane criteria. The initial search yielded 600 citations, of which three papers met the criteria for inclusion in this review. Studies showed a significant reduction in endotoxin following rotary and reciprocating instrumentation, with no significant differences between them. The meta-analysis showed no statistical significant difference between reciprocation and rotary files (P > 0.05). In conclusion, the instrumentation techniques compared in this review decrease endotoxin content from root canals, with no significant difference between them45340741