Stable population structure in Europe since the Iron Age, despite high mobility

Ancient DNA research in the past decade has revealed that European population structure changed dramatically in the prehistoric period (14,000–3000 years before present, YBP), reflecting the widespread introduction of Neolithic farmer and Bronze Age Steppe ancestries. However, little is known about how population structure changed from the historical period onward (3000 YBP - present). To address this, we collected whole genomes from 204 individuals from Europe and the Mediterranean, many of which are the first historical period genomes from their region (e.g. Armenia and France). We found that most regions show remarkable inter-individual heterogeneity. At least 7% of historical individuals carry ancestry uncommon in the region where they were sampled, some indicating cross-Mediterranean contacts. Despite this high level of mobility, overall population structure across western Eurasia is relatively stable through the historical period up to the present, mirroring geography. We show that, under standard population genetics models with local panmixia, the observed level of dispersal would lead to a collapse of population structure. Persistent population structure thus suggests a lower effective migration rate than indicated by the observed dispersal. We hypothesize that this phenomenon can be explained by extensive transient dispersal arising from drastically improved transportation networks and the Roman Empire’s mobilization of people for trade, labor, and military. This work highlights the utility of ancient DNA in elucidating finer scale human population dynamics in recent history

Ethylene regulators influence germination and root growth of globe artichoke seedlings exposed to heat stress conditions

High seed germination and root vigour are important traits to improve post-transplant performance of artichoke (Cynara cardunculus var. scolymus) under heat stress conditions. The effects of exogenous applications of five ethylene regulators each at different concentrations were evaluated on germination and early root growth of artichoke at 23°C in two incubation assays. The ethylene precursors or promoters were DL-methionine (DL-MET), 1-aminocyclopropane-l-carboxylic acid (ACC) and 2-chloroethylphosphonic acid (ethephon, ETH); and ethylene inhibitors were aminoethoxyvinylglycine (AVG) and 1-methylcyclopropene (1-MCP). A subsequent study examined the effects of ETH concentrations on seeds exposed at 23 vs. 30°C (stress). Seed thermodormancy was significantly improved by the application of 30 μM L-1 ETH. At optimal temperature (23°C), early root growth was enhanced by ACC and ETH (range of 1-100 μM L-1) with increasing root hair density, root area and lateral roots (except with ETH at 30 μM L-1). Conversely, AVG induced primary root elongation but decreased root hair formation. At higher temperature (30°C), inhibition of early root growth was alleviated when seedlings were incubated at 30 μM L-1 ETH. Our results suggest that exogenous ethylene could be useful to alleviate heat stress on artichoke seeds and seedlings, which in turn may improve early growth during stand establishment.Fil: Shinohara, T.. Sanyu Consultants Inc.; JapónFil: Martin, Eugenia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; ArgentinaFil: Leskovar, Daniel Ivan. Texas A&M University; Estados Unido

Physiological and Biochemical Responses of Tomato Plants Grafted onto <i>Solanum pennellii</i> and <i>Solanum peruvianum</i> under Water-Deficit Conditions

Grafting using suitable rootstocks mitigates the adverse effects caused by environmental stresses such as water deficit in the tomato crop. Solanum pennellii and Solanum peruvianum, the wild relatives of tomato, are used as rootstocks due to their tolerance to water deficit and soil-borne diseases. This study focused on evaluating physiological and biochemical responses of tomato plants grafted onto S. pennellii and S. peruvianum rootstocks during water deficit. The commercial tomato cultivar ‘HM 1823’ (HM) either self-grafted (HM/HM) or grafted onto S. pennellii (HM/PN), S. peruvianum (HM/PR), and ‘Multifort’ (HM/MU) rootstocks were subjected to water-deficit stress by withholding irrigation for eight days. The performance of the grafted plants under water deficit was evaluated using physiological and biochemical parameters in vegetative tissues of the grafted plants. Plants grafted using S. pennellii (PN) and S. peruvianum (PR) rootstocks showed higher values of water potential (Ψw), relative water content (RWC), net photosynthetic rate (A), and leaf water use efficiencies (WUE) compared to HM, HM/HM, and HM/MU. Plants grafted onto tomato wild relatives showed the lowest malondialdehyde (MDA) and proline content. This study demonstrated that the rootstocks of wild tomato relatives reduced the effect of water deficit to a greater extent through better physiological, metabolic, and biochemical adjustments than self-grafting plants

Physiological and Biochemical Responses of Tomato Plants Grafted onto Solanum pennellii and Solanum peruvianum under Water-Deficit Conditions

Grafting using suitable rootstocks mitigates the adverse effects caused by environmental stresses such as water deficit in the tomato crop. Solanum pennellii and Solanum peruvianum, the wild relatives of tomato, are used as rootstocks due to their tolerance to water deficit and soil-borne diseases. This study focused on evaluating physiological and biochemical responses of tomato plants grafted onto S. pennellii and S. peruvianum rootstocks during water deficit. The commercial tomato cultivar ‘HM 1823’ (HM) either self-grafted (HM/HM) or grafted onto S. pennellii (HM/PN), S. peruvianum (HM/PR), and ‘Multifort’ (HM/MU) rootstocks were subjected to water-deficit stress by withholding irrigation for eight days. The performance of the grafted plants under water deficit was evaluated using physiological and biochemical parameters in vegetative tissues of the grafted plants. Plants grafted using S. pennellii (PN) and S. peruvianum (PR) rootstocks showed higher values of water potential (Ψw), relative water content (RWC), net photosynthetic rate (A), and leaf water use efficiencies (WUE) compared to HM, HM/HM, and HM/MU. Plants grafted onto tomato wild relatives showed the lowest malondialdehyde (MDA) and proline content. This study demonstrated that the rootstocks of wild tomato relatives reduced the effect of water deficit to a greater extent through better physiological, metabolic, and biochemical adjustments than self-grafting plants

Biomass characterization of wild and cultivated cardoon accessions and estimation of potential biofuels production

Cardoon is considered an interesting raw material to obtain second-generation biofuels, due to its perennial culture condition and its rare use as food. In addition, cardoon, being a rustic species, requires few inputs and has fast growth and high lignocellulosic biomass production. However, despite its large genetic variability worldwide, both cardoon botanical varieties were subject only to few (cultivated cardoon)/zero (wild cardoon) breeding programs. The aims of this study were (I) to characterize biomass quality and quantity of genotypes of wild and cultivated cardoon in order to produce different types of biofuels and (II) to identify the most promising accessions to be included in breeding programs for bioenergy characteristics or to be incorporated in the local agro-productive system. The performance of twelve Cynara cardunculus L. accessions (six cultivated cardoons and six wild cardoons) was compared through biometric, chemical, and energetic characteristics. Moreover, the potential bioethanol and biomethane yields and the energy potentially generated from direct combustion were calculated for each botanical variety. Significant differences were found between botanical varieties for several biometric traits, but not in chemical traits except for ash content. Results indicate that cardoon biomass, especially cultivated cardoon, has characteristics that make this species a promising candidate to be grown for energy purposes under very low crop inputs in the local edapho-climatic conditions. In addition, our screening identified an accession that stands out based on yield, biomass composition, and potential to produce different types of biofuels/bioenergy.Fil: Mancini, Micaela. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; ArgentinaFil: Bresó, Ana Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; ArgentinaFil: Rúa, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; ArgentinaFil: Lanza Volpe, Melisa. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Leskovar, Daniel Ivan. Texas A&M University; Estados UnidosFil: Cravero, Vanina Pamela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; Argentin

Characterization of cardoon accessions as feedstock for biodiesel production

Diesel fuels have an essential function in industrial economies. In the last decade, several studies were conducted in order to find alternative sources of vegetables oils suitable to biodiesel conversion. The present work aimed to characterize the oil chemical composition in eleven different accessions of domestic and wild cardoon (Cynara cardunculus L. var. altilis and var. sylvestris, respectively) in order to evaluate its putative use as an alternative energy crop, with main focus in biodiesel production. No significant differences were measured between both botanical varieties for oil content; values of 20.80 ± 6.65% were found. The highest values were observed for the wild cardoon accessions “Uruguay Centro” (35.95%) and “Pergamino” (27.78%). The fatty acid composition was similar for both botanical varieties: palmitic (10.9%), stearic (3.0%), oleic (23.5%) and linoleic (61.3%). Comparing with traditional energy crops (soybean, sunflower and rapeseed) the cardoon fatty acid profile is similar to those obtained for soybean. Several biodiesel quality parameters were calculated or estimated over different oil samples. In this way, the acidity ranged from 0.1 to 0.7 mg OH/goil, showing differences among accessions but not between botanical varieties. “Cardo Blanco Peralta” and A-41 (cultivated cardoon) presented the lowest unsaturated degree, iodine values and oleic/linoleic acid relation in their oil; consequently, they showed the most suitable values for the biodiesel quality parameters (cetane number and kinetic viscosity). Based on seed oil composition, this characterization, allowed demonstrating that cardoon oil has appropriate characteristics to be used as feedstock for the production of biodiesel, as well as, to detect accessions with superior quality properties.Fil: Mancini, Micaela. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Lanza Volpe, Melisa. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria Mendoza. Laboratorio de Fitovirología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gatti, María Bernardita. Universidad del Centro Educativo Latinoamericano; ArgentinaFil: Malik, Yair Fernando. Universidad del Centro Educativo Latinoamericano; ArgentinaFil: Morero, Ana Carina. Universidad del Centro Educativo Latinoamericano; ArgentinaFil: Leskovar, Daniel Ivan. Texas A&M Agrilife Research Center; Estados UnidosFil: Cravero, Vanina Pamela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; Argentin

Stable population structure in Europe since the Iron Age, despite high mobility

International audienceAncient DNA research in the past decade has revealed that European populationstructure changed dramatically in the prehistoric period (14,000–3000 years before present, YBP),reflecting the widespread introduction of Neolithic farmer and Bronze Age Steppe ancestries.However, little is known about how population structure changed from the historical period onward(3000 YBP - present). To address this, we collected whole genomes from 204 individuals fromEurope and the Mediterranean, many of which are the first historical period genomes from theirregion (e.g. Armenia and France). We found that most regions show remarkable inter-individualheterogeneity. At least 7% of historical individuals carry ancestry uncommon in the region wherethey were sampled, some indicating cross-Mediterranean contacts. Despite this high level ofmobility, overall population structure across western Eurasia is relatively stable through the historicalperiod up to the present, mirroring geography. We show that, under standard population geneticsmodels with local panmixia, the observed level of dispersal would lead to a collapse of populationstructure. Persistent population structure thus suggests a lower effective migration rate than indi-cated by the observed dispersal. We hypothesize that this phenomenon can be explained by exten-sive transient dispersal arising from drastically improved transportation networks and the RomanEmpire’s mobilization of people for trade, labor, and military. This work highlights the utility ofancient DNA in elucidating finer scale human population dynamics in recent history