Adaptive Introgression: An Untapped Evolutionary Mechanism for Crop Adaptation

Global environmental changes strongly impact wild and domesticated species biology and their associated ecosystem services. For crops, global warming has led to significant changes in terms of phenology and/or yield. To respond to the agricultural challenges of this century, there is a strong need for harnessing the genetic variability of crops and adapting them to new conditions. Gene flow, from either the same species or a different species, may be an immediate primary source to widen genetic diversity and adaptions to various environments. When the incorporation of a foreign variant leads to an increase of the fitness of the recipient pool, it is referred to as “adaptive introgression”. Crop species are excellent case studies of this phenomenon since their genetic variability has been considerably reduced over space and time but most of them continue exchanging genetic material with their wild relatives. In this paper, we review studies of adaptive introgression, presenting methodological approaches and challenges to detecting it. We pay particular attention to the potential of this evolutionary mechanism for the adaptation of crops. Furthermore, we discuss the importance of farmers’ knowledge and practices in shaping wild-to-crop gene flow. Finally, we argue that screening the wild introgression already existing in the cultivated gene pool may be an effective strategy for uncovering wild diversity relevant for crop adaptation to current environmental changes and for informing new breeding directions

Narrow genetic base in forest restoration with holm oak (Quercus ilex L.) in Sicily

In order to empirically assess the effect of actual seed sampling strategy on genetic diversity of holm oak (Quercus ilex) forestations in Sicily, we have analysed the genetic composition of two seedling lots (nursery stock and plantation) and their known natural seed origin stand by means of six nuclear microsatellite loci. Significant reduction in genetic diversity and significant difference in genetic composition of the seedling lots compared to the seed origin stand were detected. The female and the total effective number of parents were quantified by means of maternity assignment of seedlings and temporal changes in allele frequencies. Extremely low effective maternity numbers were estimated (Nfe $\approx$ 2-4) and estimates accounting for both seed and pollen donors gave also low values (Ne $\approx$ 35-50). These values can be explained by an inappropriate forestry seed harvest strategy limited to a small number of spatially close trees

El género Orobanche L. (Orobanchaceae) en Andalucía

RESUMEN. El género Orobanche L. (Orobanchaceae) en Andalucía. Se actualiza el conocimiento del género Orobanche L. para la Flora de Andalucía, sur de la Península Ibérica. La revisión se ha hecho mediante el análisis crítico de la información bibliográfica y de los principales herbarios relacionados con el territorio. Para facilitar la identificación de las diferentes especies aportamos una clave de determinación. Para los 31 taxones presentes aportamos su distribución detallada en unidades geográficas así como su categoría UICN. Resaltamos la presencia de taxones de marcado interés corológico, poco citados en todo el territorio, como O. ramosa, O. olbiensis, O. mariana, O. lavandulacea, O. schultzii, O. mutelii subsp. georgii-reuteri, O. purpurea, O. clausonis, O. rapumgenistae, O. gracilis subsp. deludens, O. haenseleri, O. alba, O. icterica, O. amethystea subsp. castellana, O. almeriensis, O. santolinae. Consideramos que especies como O. sanguinea, O. crinita, O. variegata, O. caryophyllaceae, O. lutea, O. reticulata y O. artemisiae-campestris no se encuentran en Andalucía y a O. calendulae como especie conflictiva a buscar.Palabras clave. Orobanche, Orobanchaceae, jopo, parásita, corología, Andalucía.ABSTRACT. The genus Orobanche (Orobanchaceae) in Andalusia. A botanical survey has been carried out in order to improve the knowledge of the genus Orobanche L. of the Flora of Andalusia, South of the Iberian Peninsula. With this aim, a critical review of the concerning bibliographical information and of the main territorial herbaria was accomplished. An identification key is provided. For each of the 31 taxa considered its detailed distribution in geographical units as well as its category UICN are given. The presence of taxa of important chorological interest such as O. ramosa, O. olbiensis, O. mariana, O. lavandulacea, O. schultzii, O. mutelii subsp. georgii-reuteri, O. purpurea, O. clausonis, O. rapum-genistae, O. gracilis subsp. deludens, O. haenseleri, O. alba, O. icterica, O. amethystea subsp. castellana, O. almerienses, O. santolinae is pointed out. Moreover, we consider that O. sanguinea, O. crinita, O. variegata, O. caryophyllaceae, O. lutea, O. reticulata and O. artemisiaecampestris are species not found in Andalusia and O. calendulae is a conflictive taxon to investigate.Key words. Orobanche, Orobanchaceae, broomrape, parasite, chorology, Andalusia

The genetic legacy of the expansion of Bantu-speaking peoples in Africa.

The expansion of people speaking Bantu languages is the most dramatic demographic event in Late Holocene Africa and fundamentally reshaped the linguistic, cultural and biological landscape of the continent1-7. With a comprehensive genomic dataset, including newly generated data of modern-day and ancient DNA from previously unsampled regions in Africa, we contribute insights into this expansion that started 6,000-4,000 years ago in western Africa. We genotyped 1,763 participants, including 1,526 Bantu speakers from 147 populations across 14 African countries, and generated whole-genome sequences from 12 Late Iron Age individuals8. We show that genetic diversity amongst Bantu-speaking populations declines with distance from western Africa, with current-day Zambia and the Democratic Republic of Congo as possible crossroads of interaction. Using spatially explicit methods9 and correlating genetic, linguistic and geographical data, we provide cross-disciplinary support for a serial-founder migration model. We further show that Bantu speakers received significant gene flow from local groups in regions they expanded into. Our genetic dataset provides an exhaustive modern-day African comparative dataset for ancient DNA studies10 and will be important to a wide range of disciplines from science and humanities, as well as to the medical sector studying human genetic variation and health in African and African-descendant populations

Catálogo de las especies españolas de flora incluidas en los apéndices CITES

Tésis presentada para el "II Máster sobre Gestión, Conservación y Control de Especies Sometidas a Comercio Internacional" de la Universidad Internacional de Andalucía (Baeza) en el año 2001.<br

Demographic inference using skyline plots on approximate bayesian computation

Bayesian Skyline Plots (BSPs) are representations of the posterior probability density of the effective population size in function of time; i.e. a graphical representation of the fluctuation of the effective population size with time based on the estimates obtained from Bayesian inference. The interest of BSPs is that they allow to infer gradual changes of the effective population size without the need of a specific mathematical function determining the shape of the demographic change. For instance, a population expansion can be well characterized by a BSP either if the change had ocurred instantaneously, exponentially or logistically.. Currently, the only implementation of this analysis has been done within the MCMC-based estimation of likelihood approach and is restricted to non-recombining DNA sequence data. We have explored how to implement BSP within the approximate Bayesian computation (ABC) framework, with promising preliminary results. An implementation in ABC allows to obtain BSP from any multilocus molecular data, e.g. recombining DNA sequence data, microsatellites, AFLPs or SNPs

Mutation rate estimates for 110 Y-chromosome STRs combining population and father–son pair data

Y-chromosome microsatellites (Y-STRs) are typically used for kinship analysis and forensic identification, as well as for inferences on population history and evolution. All applications would greatly benefit from reliable locus-specific mutation rates, to improve forensic probability calculations and interpretations of diversity data. However, estimates of mutation rate from father–son transmissions are available for few loci and have large confidence intervals, because of the small number of meiosis usually observed. By contrast, population data exist for many more Y-STRs, holding unused information about their mutation rates. To incorporate single locus diversity information into Y-STR mutation rate estimation, we performed a meta-analysis using pedigree data for 80 loci and individual haplotypes for 110 loci, from 29 and 93 published studies, respectively. By means of logistic regression we found that relative genetic diversity, motif size and repeat structure explain the variance of observed rates of mutations from meiosis. This model allowed us to predict locus-specific mutation rates (mean predicted mutation rate 2.12 × 10−3, SD=1.58 × 10−3), including estimates for 30 loci lacking meiosis observations and 41 with a previous estimate of zero. These estimates are more accurate than meiosis-based estimates when a small number of meiosis is available. We argue that our methodological approach, by taking into account locus diversity, could be also adapted to estimate population or lineage-specific mutation rates. Such adjusted estimates would represent valuable information for selecting the most reliable markers for a wide range of applications