Fernando Hernández

University of British Columbia | UBC · Biodiversity Research Centre

Premise of the study: Cultivated species and their wild relatives often hybridize in the wild and crop-wild hybrids can survive and reproduce in some environments. However, it is unclear whether cultivar alleles are permanently incorporated into the wild genomes or whether they are purged by natural selection. This question is key to accurately as...

Premise: The phenotype of hybrids between a crop and its wild or weed counterpart is usually intermediate and maladapted compared to that of their parents; however, hybridization has sometimes been associated with increased fitness, potentially leading to enhanced weediness and invasiveness. Since the ecological context and maternal genetic effect...

Biological invasions represent an extraordinary opportunity to study evolution. This is because accidental or deliberate species introductions have taken place for centuries across large geographical scales, in natural and anthropogenic environments. Until recently however, the utility of invasions as evolutionary experiments has been hampered by t...

Germination and emergence are critical life stages for annual plants and so their understanding is key for managing weed populations. Here, we conducted experiments to investigate the effect of temperature, light, pericarp and dry storage on dormancy and germination, and the effect of depth and irrigation on seedling emergence in the weed Raphanus...

Aim: Arctic plants survived the Pleistocene glaciations in unglaciated refugia, but the number of these refugia is often unclear. We use high-resolution genomic data from present-day and Little-Ice-Age populations of Arctic White Heather (Cassiope tetragona) to re-evaluate the biogeography of this species and determine whether it had multiple indep...

PREMISE Crop-wild/weed hybrids usually exhibit intermediate and maladapted phenotypes compared to their parents; however, hybridization has sometimes been associated with increased fitness, potentially leading to enhanced weediness and invasiveness. Since the ecological context and maternal genetic effects may affect hybrid fitness, they could infl...

Agricultural weeds descended from domesticated ancestors, directly from crops (endoferality) and/or from crop-wild hybridization (exoferality), may have evolutionary advantages by rapidly acquiring traits pre-adapted to agricultural habitats. Understanding the role of crops on the origin and evolution of agricultural weeds is essential to develop m...

Cultivated species and their wild relatives often hybridize in the wild and crop-wild hybrids can survive and reproduce in some environments. However, it is unclear whether crop alleles are permanently incorporated into the wild genomes in the long run or whether they are purged by natural selection. This question is key to accurately assessing the...

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Alongside the use of fertilizer and chemical control of weeds, pests, and diseases modern breeding has been very successful in generating cultivars that have increased agricultural production several fold in favorable environments. These typically homogeneous cultivars (either homozygous inbreds or hybrids derived from inbred parents) are bred unde...

Based on case studies, in this chapter we discuss the extent to which the number and identity of quantitative trait loci (QTL) identified from genome-wide association studies (GWAS) are affected by curation and analysis of phenotypic data. The chapter demonstrates through examples the impact of (1) cleaning of outliers, and of (2) the choice of sta...

Aims: Invasive alien plants threaten biodiversity across the world. Erigeron canadensis (horseweed) is considered one of the most problematic agricultural weeds and represents a classic example of inter-continental invasion. Here, we studied the genetic diversity and population structure of invasive alien populations from the Jiangsu and Zhejiang P...

Hybridization between crops and their wild relatives may promote the evolution of de-domesticated (feral) weeds. Wild sunflower (Helianthus annuus L.) is typically found in ruderal environments, but crop-wild hybridization may facilitate the evolution of weedy populations. Using one crop-specific mitochondrial marker (CMS-PET1) and 14 nuclear SSR m...

El nabón (Raphanus sativus L.) es una maleza problemática ampliamente difundida en las regiones templadas de América que ha desarrollado resistencia a los herbicidas inhibidores de la enzima acetohidroxiácido sintasa (AHAS) debido a la mutación Trp574Leu. Las mutaciones que aportan resistencia a herbicidas inhibidores de AHAS pueden estar asociadas...

Hybridization between crops and their wild relatives may promote the evolution of de-domesticated (feral) weeds. Wild sunflower is typically found in ruderal environments, but crop-wild hybridization may facilitate the evolution of weedy biotypes. Using one crop-specific mitochondrial marker (CMS-PET1) and 14 nuclear SSR markers, we studied the ori...

Gene mutations endowing herbicide resistance may have negative pleiotropic effects on plant fitness. Quantifying these effects is critical for predicting the evolution of herbicide resistance and developing management strategies for herbicide‐resistant weeds. This study reports the effects of the acetohydroxyacid synthase (AHAS) Trp574Leu mutation...

• When cultivated and wild plants hybridize, hybrids often show intermediate phenotypic traits relative to their parents, which make them unfit in natural environments. However, maternal genetic effects may affect the outcome of hybridization by controlling the expression of the earliest life history traits. • Here, using wild, cultivated, and reci...

El flujo génico entre plantas cultivadas y silvestres emparentadas (hibridación cultivo-silvestre) puede dar lugar a la aparición de biotipos híbridos con un fenotipo intermedio entre ambos padres (rasgos cultivados y silvestres en la misma planta). La evolución de estos híbridos (desaparición vs. adaptación) dependerá de cómo opere la selección am...

Gene mutations endowing herbicide resistance may have negative pleiotropic effects on plant fitness. Quantifying these effects is critical for predicting the evolution of herbicide resistance and developing management strategies for herbicide resistant weeds. This study reports the effects of the acetohydroxyacid synthase (AHAS) Trp574Leu mutation...

When cultivated and wild plants hybridize, hybrids often show intermediate phenotypic traits relative to their parents, which make them unfit in natural environments. However, maternal genetic effects may affect the outcome of hybridization by controlling the expression of the earliest life history traits. Here, using wild, cultivated, and reciproc...

The increased incidence of extreme temperature events due to global climate change poses a major challenge for crop production. Ability to increase temperature tolerance through genetic improvement requires understanding of how crops and their wild relatives respond to extreme temperatures. We developed a high-throughput technique to evaluate toler...

Aims The ability to form persistent seed banks is one of the best predictors of species´ potential to establish in new ranges. Wild sunflower is native to North America where the formation of persistent seed banks is promoted by disturbance and it plays a key role on the establishment and persistence of native populations. However, the role of the...

Aumentos en la variabilidad climática aumentan la ocurrencia de temperaturas extremas, afectando el establecimiento y rendimiento de los cultivos. Los parientes silvestres de los cultivos están adaptados a una amplia variedad de ambientes, por lo tanto representan una excelente fuente de tolerancia a temperaturas extremas (TTE), sin embargo la dive...

Invasive plants represent a valuable model system for studying contemporary evolution and predicting evolutionary responses to global climate change. Rapid adaptation to climate during range expansion has been recently recognised as a major factor in biological invasions. In this study, by using complementary approaches (common garden studies and t...

Studying the levels and patterns of genetic diversity of invasive populations is important to understand the evolutionary and ecological factors promoting invasions and for better designing preventive and control strategies. Wild sunflower (Helianthus annuus L.) is native to North America and was introduced, and has become invasive, in several coun...

Twenty-three variables registered on 374 plants from 15 populations

Hybridization is a common phenomenon in plants and can lead to the introgression of alleles from one population into another, generate new hybrid lineages, or cause species extinction. The environmental conditions and the genetic background of the participating populations may influence these outcomes since they can affect the fitness of hybrids, t...

Invasive plants represent a major environmental and economic threat, but they are also valuable models to study contemporary evolution and to predict evolutionary responses to global change. Crop wild relatives are a special case of invasive species because their presence can limit the use of technology in their crop relatives, crop-wild hybridizat...

Heat stress (HS) is a major threat to current and future crop production. Crop improvement for HS tolerance is a major tool for dealing with HS and crop wild relatives (CWR) offer the greatest variability for such improvement. Here, we evaluated the HS tolerance on four reproductive traits in cultivated and wild sunflower and tested for local adapt...

Agricultural weeds are plants well-adapted to agricultural environments interfering directly and indirectly with crop production and causing important economic losses worldwide. Crop-wild hybridization is one of the main forces that have ruled weed evolution along with adaptation to agricultural (or benign) environments. Considering the competing d...

Hybridisation between crops and their wild relativesmay promote the evolution of weeds. Seed germination and dormancy are the earliest life-history traits and are highly influenced by the maternal parent. However, the ecological role of the maternal effect on seed traits in the evolution of crop–wild hybrids has received little attention. In this s...

La introgresión de genes del cultivo en poblaciones silvestres emparentadas puede acelerar la adaptación de estas a nuevos ambientes, como los agro-ecosistemas. En Argentina, las poblaciones silvestres de girasol se comportan como ruderales y en algunos pocos casos, como malezas de los cultivos. El objetivo del trabajo fue evaluar el efecto de la i...

Maize (Zea mays L.) grain yield has a parabolic response to stand density changes, creating an optimum stand density that maximizes yield. Argentinean commercial hybrids differ in their optimum stand density when grown at similar environments, generating the need to test precommercial hybrids for adequate product management recommendations. For bre...

Maize (Zea mays L.) stand density selection is an important management practice because yield is maximized at a particular optimum value. Optimum stand density (OSD) varies across environments, and many have argued that current commercial genotypes differ in their optimum stand density for a similar environment. We tested this concept by planting 1...