Iris Sheila Collenette

Abstract  Background and aims Crop wild relatives, exposed to strong natural selection, exhibit effective tolerance traits against stresses. While an aggressive root proliferation phenotype has long been considered advantageous for a range of stresses, it appears to be counterproductive under drought due to its high metabolic cost. Recently, a parsimonious root phenotype, metabolically more efficient, has been suggested to be better adapted to semiarid environments, although it is not clear that this phenotype is a trait exhibited by crop wild relatives. Methods Firstly, we analysed the root phenotype and carbon metabolism in four Medicago crop wild relatives adapted to a semiarid environment and compared them with the cultivated M. truncatula Jemalong (A17). Secondly, we exposed the cultivated (probably the least adapted genotype to aridity) and the wild (the most common one in arid zones) M. truncatula genotypes to water deficit. The carbon metabolism response in different parts of their roots was analysed. Results A reduced carbon investment per unit of root length was a common trait in the four wild genotypes, indicative of an evolution towards a parsimonious root phenotype. During the water deficit experiment, the wild M. truncatula showed higher tolerance to drought, along with a superior ability of its taproot to partition sucrose and enhanced capacity of its fibrous roots to maintain sugar homeostasis. Conclusion A parsimonious root phenotype and the spatial specialization of root carbon metabolism represent two important drought tolerance traits. This work provides relevant findings to understand the response of Medicago species roots to water deficit.

AbstractPremiseThe ecological conditions that constrain plants to an environmental niche are assumed to be constant through time. While the fossil record has been used previously to test for niche conservatism of woody flowering plants, additional studies are needed in other plant groups especially since they can provide insight with paleoclimatic reconstructions, high biodiversity in modern terrestrial ecosystems, and significant contributions to agriculture.MethodsWe tested climatic niche conservatism across time by characterizing the climatic niches of living herbaceous ginger plants (Zingiberaceae) and woody dawn redwood (Metasequoia) against paleoniches reconstructed based on fossil distribution data and paleoclimatic models.ResultsDespite few fossil Zingiberaceae occurrences in the latitudinal tropics, unlike living Zingiberaceae, extinct Zingiberaceae likely experienced paratropical conditions in the higher latitudes, especially in the Cretaceous and Paleogene. The living and fossil distributions of Metasequoia largely remain in the upper latitudes of the northern hemisphere. The Zingiberaceae shifted from an initial subtropical climatic paleoniche in the Cretaceous, toward a temperate regime in the late Cenozoic; Metasequoia occupied a more consistent climatic niche over the same time intervals.ConclusionsBecause of the inconsistent climatic niches of Zingiberaceae over geologic time, we are less confident of using them for taxonomic‐based paleoclimatic reconstruction methods like nearest living relative, which assume a consistent climatic niche between extant and extinct relatives; we argue that the consistent climatic niche of Metasequoia is more appropriate for these reconstructions. Niche conservatism cannot be assumed between extant and extinct plants and should be tested further in groups used for paleoclimatic reconstructions.

Multiple‐island endemics (MIE) are considered ideal natural subjects to study patterns of island colonization that involve recent population‐level genetic processes. Kleinia neriifolia is a Canarian MIE widespread across the archipelago, which exhibits a close phylogenetic relationship with species in northwest Africa and at the other side of the Sahara Desert. Here, we used target sequencing with plastid skimming (Hyb‐Seq), a dense population‐level sampling of K. neriifolia, and representatives of its African–southern Arabian relatives to infer phylogenetic relationships and divergence times at the species and population levels. Using population genetic techniques and machine learning (convolutional neural networks [CNNs]), we reconstructed phylogeographic relationships and patterns of genetic admixture based on a multilocus SNP nuclear dataset. Phylogenomic analysis based on the nuclear dataset identifies the northwestern African Kleinia anteuphorbium as the sister species of K. neriifolia, with divergence starting in the early Pliocene. Divergence from its sister clade, comprising species from the Horn of Africa and southern Arabia, is dated to the arid Messinian period, lending support to the climatic vicariance origin of the Rand Flora. Phylogeographic model testing with CNNs supports an initial colonization of the central island of Tenerife followed by eastward and westward migration across the archipelago, which resulted in the observed east/west phylogeographic split. Subsequent population extinctions linked to aridification events, and recolonization from Tenerife, are proposed to explain the patterns of genetic admixture in the eastern Canary Islands. We demonstrate that CNNs based on SNPs can be used to discriminate among complex scenarios of island migration and colonization.

Traits associated with successful biological invasions across environmental gradients or geographical distances may vary depending on processes such as founder effects, ecological sorting, or adaptation to local conditions. Consequently, drivers of success are not necessarily consistent throughout the invasive range. We evaluate how plant traits, reproductive success and climatic preferences vary in populations of a naturalized orchid on islands in the Atlantic, Pacific and Indian oceans. Populations of Arundina graminifolia (bamboo orchid) were located on Puerto Rico, Hawaiian Islands (Hawai’i, O’ahu, Kaua’i), and Mauritius. Vegetative and reproductive traits were measured, and male and female success were assessed. Populations were compared using multivariate approaches. Species distribution modeling was used to assess potential climatic preferences within and among islands. Floral morphology differed among islands but considerable overlap in trait distributions exists. Reproductive success significantly differed among islands and was linked to floral traits, local pollinator pools and perhaps variable levels of florivory. Hawaiian populations occupied the broadest climatic niche space and Mauritius the most restricted. The effectiveness of using present points from the native range to reveal climatic suitability on invaded islands varied among islands. Successful invasions across a broad geographical range can occur even when morphology, reproductive success and climatic conditions are variable. As expected, some aspects of this global invasion are similar, but others differ among islands underscoring the context dependency of biological invasions and the difficulty of overall predictions. Los rasgos asociados a las invasiones biológicas exitosas a través de gradientes ambientales o distancias geográficas pueden variar dependiendo de procesos tales como el efecto fundador, el sorteo ecológico, o las adaptaciones a las condiciones locales. Consecuentemente, los impulsores del éxito no son necesariamente consistentes a través de la distribución invadida. Nosotros evaluamos cómo los rasgos, el éxito reproductivo y las preferencias climáticas varían en poblaciones de una orquídea naturalizada en islas de los océanos Atlántico, Pacífico e Índico. Las poblaciones de Arundina graminifolia (orquídea bambú) estaban localizadas en Puerto Rico, las Islas Hawaianas (Hawai’i, O’ahu, Kaua’i) y en la Isla de Mauricio. Los rasgos vegetativos y reproductivos fueron medidos, y el éxito reproductivo masculino y femenino fue evaluado. Comparamos las poblaciones usando enfoques estadísticos multivariados. También usamos modelos de distribución de especies para evaluar las preferencias climáticas tanto dentro de las islas, así como entre ellas. La morfología floral difirió entre islas, pero existe un sobrelapamiento considerable en la distribución de rasgos. El éxito reproductivo fue significativamente diferente entre islas, y estuvo ligado a los rasgos florales, el conjunto de polinizadores locales y, quizá, a niveles variables de florivoría. Las poblaciones hawaianas ocuparon el nicho climático más amplio mientras que las mauricianas ocuparon el más restringido. La efectividad de usar puntos de presencia de la distribución nativa para revelar la adecuación climática de las islas invadidas varió entre islas. Encontramos que las invasiones exitosas a través de una distribución geográfica amplia pueden ocurrir a pesar de la variabilidad en morfología, éxito reproductivo y condiciones climáticas. Como era de esperarse, algunos aspectos de esta invasión global son similares, pero otros difieren entre islas, haciendo hincapié en la dependencia del contexto de las invasiones biológicas y la dificultad de hacer predicciones generalizadas. Les traits associés aux invasions biologiques sur des gradients environnementaux ou des distances géographiques peuvent varier en fonction de processus tels que les effets fondateurs, le tri écologique ou l'adaptation aux conditions locales. Par conséquent, les facteurs de réussite ne sont pas nécessairement cohérents dans l'ensemble de l'aire de répartition de l'invasion. Nous évaluons comment les caractéristiques des plantes, le succès de la reproduction et les préférences climatiques varient dans les populations d'une orchidée naturalisée sur des îles des océans Atlantique, Pacifique et Indien. Les populations d'Arundina graminifolia (orchidée bambou) ont été localisées à Porto Rico, dans les îles hawaïennes (Hawai'i, O'ahu, Kaua'i) et à l'île Maurice. Les traits végétatifs et reproductifs ont été mesurés, et le succès reproductifs des mâles et des femelles a été évalué. Les populations ont été comparées à l'aide d'approches multivariées. La modélisation de la distribution des espèces a été utilisée pour évaluer les préférences climatiques potentielles au sein des îles et entre elles. La morphologie florale diffère d'une île à l'autre, mais il existe un chevauchement considérable dans la répartition des caractéristiques. Le succès de la reproduction diffère significativement entre les îles et est lié aux caractéristiques florales, aux réservoirs locaux de pollinisateurs et peut-être à des niveaux variables de florivorie. Les populations hawaïennes ont occupé la niche climatique la plus large et les populations mauriciennes la plus restreinte. L'efficacité de l'utilisation de points de présences dans l'aire de répartition indigène pour révéler l'adéquation climatique des îles envahies varie d'une île à l'autre. Des invasions réussies sur une vaste aire de répartition géographique peuvent se produire même lorsque la morphologie, le succès de la reproduction et les conditions climatiques sont variables. Comme prévu, certains aspects de cette invasion mondiale sont similaires, mais d'autres diffèrent d'une île à l'autre, ce qui souligne l’importance du contexte des invasions biologiques et la difficulté des prédictions globales.

Spatial truncation in species distribution models (SDMs) might cause niche truncation and model transferability issues, particularly when extrapolating models to non‐analog environmental conditions. While broad calibration extents reduce truncation issues, they usually overlook local ecological factors driving species distributions at finer resolution. Spatially‐nested hierarchical SDMs (HSDMs) address truncation by merging (a) a global model calibrated with broadly extended, yet typically low‐resolution, basic, and imprecise data; and (b) a regional model calibrated with spatially restricted but more precise and reliable data. This study aimed to examine HSDMs' efficacy to overcome spatial truncation in national‐scale studies. We compared two hierarchical strategies (‘covariate', which uses the global model output as a covariate for the regional model, and ‘multiply', which calculates the geometric mean of the global and regional models) and a non‐hierarchical strategy. The three strategies were compared in terms of niche truncation, environmental extrapolation, model performance, species' predicted distributions and shifts, and trends in species richness. We examined the consistency of the results over two study areas (Spain and Switzerland), 108 tree species, and four future climate scenarios. Only the non‐hierarchical strategy was susceptible to niche truncation, and environmental extrapolation issues. Hierarchical strategies, particularly the ‘covariate' one, presented greater model accuracy than non‐hierarchical strategies. The non‐hierarchical strategy predicted the highest overall values and the lowest decreases over time in species distribution ranges and richness. Differences between strategies were more evident in Switzerland, which was more affected by niche truncation issues. Spain was more negatively affected by climate change and environmental extrapolation. The ‘covariate' strategy exhibited higher model performance than the ‘multiply' one. However, uncertainties regarding model temporal transferability advocate for adopting and further examining multiple hierarchical approaches. This research underscores the importance of adopting spatially‐nested hierarchical SDMs given the compromised reliability of non‐hierarchical approaches due to niche truncation and extrapolation issues.

Parasitic weeds in the genera Orobanche, Phelipanche (broomrapes) and Striga (witchweeds) have a devastating impact on food security across much of Africa, Asia and the Mediterranean Basin. Yet, how climatic factors might affect the range expansion of these weeds in the context of global environmental change remains unexplored. We examined satellite‐based environmental variables such as surface temperature, root zone soil moisture, and elevation, in relation to parasitic weed distribution and environmental conditions over time, in combination with observational data from the Global Biodiversity Information Facility (GBIF). Our analysis reveals contrasting environmental and altitude preferences in the genera Striga and Orobanche. Asiatic witchweed (Striga asiatica), which infests corn, rice, sorghum, and sugar cane crops, appears to be expanding its range in high elevation habitats. It also shows a significant association with heat‐moisture coupling events, the frequency of which is rising in such environments. These results point to geographical shifts in distribution and abundance in parasitic weeds due to climate change.

Aim Species occurrence data are valuable information that enables one to estimate geographical distributions, characterize niches and their evolution, and guide spatial conservation planning. Rapid increases in species occurrence data stem from increasing digitization and aggregation efforts, and citizen science initiatives. However, persistent quality issues in occurrence data can impact the accuracy of scientific findings, underscoring the importance of filtering erroneous occurrence records in biodiversity analyses.InnovationWe introduce an R package, occTest, that synthesizes a growing open‐source ecosystem of biodiversity cleaning workflows to prepare occurrence data for different modelling applications. It offers a structured set of algorithms to identify potential problems with species occurrence records by employing a hierarchical organization of multiple tests. The workflow has a hierarchical structure organized in testPhases (i.e. cleaning vs. testing) that encompass different testBlocks grouping different testTypes (e.g. environmental outlier detection), which may use different testMethods (e.g. Rosner test, jacknife,etc.). Four different testBlocks characterize potential problems in geographic, environmental, human influence and temporal dimensions. Filtering and plotting functions are incorporated to facilitate the interpretation of tests. We provide examples with different data sources, with default and user‐defined parameters. Compared to other available tools and workflows, occTest offers a comprehensive suite of integrated tests, and allows multiple methods associated with each test to explore consensus among data cleaning methods. It uniquely incorporates both coordinate accuracy analysis and environmental analysis of occurrence records. Furthermore, it provides a hierarchical structure to incorporate future tests yet to be developed.Main conclusionsoccTest will help users understand the quality and quantity of data available before the start of data analysis, while also enabling users to filter data using either predefined rules or custom‐built rules. As a result, occTest can better assess each record's appropriateness for its intended application.

The genus Malaxis (family Orchidaceae), comprises nearly 183 species available across the globe. The plants of this genus have long been employed in traditional medical practices because of their numerous biological properties, like the treatment of infertility, hemostasis, burning sensation, bleeding diathesis, fever, diarrhea, dysentery, febrifuge, tuberculosis, etc. Various reports highlight their phytochemical composition and biological activities. However, there is a lack of systematic review on the distribution, phytochemistry, and biological properties of this genus. Hence, this study aims to conduct a thorough and critical review of Malaxis species, covering data published from 1965 to 2022 with nearly 90 articles. Also, it examines different bioactive compounds, their chemistry, and pharmacotherapeutics as well as their traditional uses. A total of 191 unique compounds, including the oil constituents were recorded from Malaxis species. The highest active ingredients were obtained from Malaxis acuminata (103) followed by Malaxis muscifera (50) and Malaxis rheedei (33). In conclusion, this review offers an overview of the current state of knowledge on Malaxis species and highlights prospects for future research projects on them. Additionally, it recommends the promotion of domestication studies for rare medicinal orchids like Malaxis and the prompt implementation of conservation measures.

Brassica napus , a versatile crop with significant socioeconomic importance, serves as a valuable source of nutrition for humans and animals while also being utilized in biodiesel production. The expansion potential of B. napus is profoundly influenced by climatic variations, yet there remains a scarcity of studies investigating the correlation between climatic factors and its distribution. This research employs CLIMEX to identify the current and future ecological niches of B. napus under the RCP 8.5 emission scenario, utilizing the Access 1.0 and CNRM-CM5 models for the time frame of 2040–2059. Additionally, a sensitivity analysis of parameters was conducted to determine the primary climatic factors affecting B. napus distribution and model responsiveness. The simulated outcomes demonstrate a satisfactory alignment with the known current distribution of B. napus , with 98% of occurrence records classified as having medium to high climatic suitability. However, the species displays high sensitivity to thermal parameters, thereby suggesting that temperature increases could trigger shifts in suitable and unsuitable areas for B. napus , impacting regions such as Canada, China, Brazil, and the United States.

Aim Fruit selection by animal dispersers with different mobility directly impacts plant geographical range size, which, in turn, may impact plant diversification. Here, we examine the interaction between fruit colour, range size and diversification rate in palms by testing two hypotheses: (1) species with fruit colours attractive to birds have larger range sizes due to high dispersal ability and (2) disperser mobility affects whether small or large range size has higher diversification, and intermediate range size is expected to lead to the highest diversification rate regardless of disperser. Location Global. Time Period Contemporary (or present). Major Taxa Studied Palms (Arecaceae). Methods Palm species were grouped based on likely animal disperser group for given fruit colours. Range sizes were estimated by constructing alpha convex hull polygons from distribution data. We examined disperser group, range size or an interaction of both as possible drivers of change in diversification rate over time in a likelihood dynamic model (Several Examined State-dependent Speciation and Extinction [SecSSE]). Models were fitted, rate estimates were retrieved and likelihoods were compared to those of appropriate null models. Results Species with fruit colours associated with mammal dispersal had larger ranges than those with colours associated with bird dispersal. The best fitting SecSSE models indicated that the examined traits were not the primary driver of the heterogeneity in diversification rates in the model. Extinction rate complexity had a marked impact on model performance and on diversification rates. Main Conclusions Two traits related to dispersal mobility, range size and fruit colour, were not identified as the main drivers of diversification in palms. Increased model extinction rate complexity led to better performing models, which indicates that net diversification should be estimated rather than speciation alone. However, increased complexity may lead to incorrect SecSSE model conclusions without careful consideration. Finally, we find palms with more mobile dispersers do not have larger range sizes, meaning other factors are more important determinants of range size.