Biology subjects

Vercellino, R. B.

Publications and source records attributed to Vercellino, R. B..

6 recordsLinked to original sources

bioRxiv2024

Admixture with cultivated sunflower likely facilitated establishment and spread of wild sunflower (H. annuus) in Argentina

A better understanding of the genetic and ecological factors underlying successful invasions is critical to mitigate the negative impacts of invasive species. Here, we study the invasion history of Helianthus annuus populations from Argentina, with particular emphasis on the role of post-introduction admixture with cultivated sunflower (also H. annuus) and climate adaptation driven by large haploblocks. We conducted genotyping-by-sequencing of samples of wild populations as well as Argentinian cultivars and compared them with wild (including related annual Helianthus species) and cultivated samples from the native range. We also characterized samples for 11 known haploblocks associated with environmental variation in native populations to test whether haploblocks contributed to invasion success. Population genomics analyses supported two independent geographic sources for Argentinian populations, the central United States and Texas, but no significant contribution of related annual Helianthus species. We found pervasive admixture with cultivated sunflower, likely as result of post-introduction hybridization. Genomic scans between invasive populations and their native sources identified multiple genomic regions with evidence of selection in the invaded range. These regions significantly overlapped between the two native-invasive comparisons and showed disproportionally high crop ancestry, suggesting that crop alleles contributed to invasion success. We did not find evidence of climate adaptation mediated by haploblocks, yet outliers of genome scans were enriched in haploblock regions and, for at least two haploblocks, the cultivar haplotype was favored in the invaded range. Our results show that admixture with cultivated sunflower played a major role in the establishment and spread of H. annuus populations in Argentina.

evolutionary biology↗

bioRxiv2023

The role of intraspecific crop-weed hybridization in the evolution of weediness and invasiveness: cultivated and feral radish (Raphanus sativus L.) as a case study

PREMISECrop-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 influence the evolutionary outcomes of hybridization. Here, we evaluated the performance of first-generation crop-weed hybrids of Raphanus sativus L. and their parents under two contrasting ecological conditions. METHODSUsing experimental hybridization and common garden experiments under field conditions, we assessed the differences in time to flowering, survival to maturity, plant biomass and reproductive components between bidirectional crop-weed hybrids and their parents, under two contrasting ecological conditions, agrestal (wheat cultivation, fertilization, weeding) and ruderal (human-disturbed uncultivated area) over two years. RESULTSCrop, weeds and bidirectional hybrids overlapped -at least partially-during the flowering period, indicating a high probability of gene flow. Hybrids survived to maturity at rates at least as successful as their parents and showed higher plant biomass and fecundity, which resulted in higher fitness compared to their parents in both contrasting environments, without any differences associated with the direction of the hybridization. CONCLUSIONSIntraspecific crop-weed hybridization, regardless of the cross direction, has the potential to promote weediness in weedy R. sativus both in agrestal and ruderal environments, increasing the chances of the introgression of crop alleles into weed populations. This is the first report of intraspecific crop-weed hybridization in R. sativus.

evolutionary biology↗

bioRxiv2021

Rapid evolution of weedy traits during sunflower de-domestication: the importance of hybridization and standing genetic variation

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 markers, we studied the origin and genetic diversity of a recently discovered weedy population of sunflower (named BRW). Then, using a resurrection approach, we tested for rapid evolution of weedy traits (seed dormancy, herbicide resistance, and competitive ability) by sampling weedy and wild populations 10 years apart (2007 and 2017). All the weedy plants present the CMS-PET1 cytotype, confirming their feral origin. At the nuclear markers, BRW showed higher genetic diversity than the cultivated lines and low differentiation with one wild population, suggesting that wild hybridization increased their genetic diversity. We found support for rapid evolution towards higher seed dormancy, but not for higher competitive ability or herbicide resistance. Our results highlight the importance of seed dormancy during the earliest stages of adaptation and show that crop-wild hybrids can evolve quickly in agricultural environments.

plant biology↗

bioRxiv2020

Interference of feral radish (Raphanus sativus) resistant to AHAS-inhibiting herbicides in oilseed rape, wheat and sunflower crops

Raphanus sativus (feral radish), a cosmopolitan weed, has developed resistance to acetohydroxyacid synthase (AHAS) inhibitor herbicides in several countries of South America. This study reports the effects of season-long interference of several feral radish densities on grain yield and yield components of oilseed rape, wheat and sunflower, and on feral radish traits under field conditions. Feral radish density treatments consisted of 0, 2, 4, 8 and 16 plants m-2 in oilseed rape, 0, 4 and 12 plants m-2 in wheat, and 0, 1.6, 4, 8 and 16 plants m-2 in sunflower. The number of inflorescences per area, seeds per inflorescence and the seed biomass of crops were reduced with increasing feral radish densities. The rectangular hyperbola model revealed yield losses by up to 100 %, 74.4 % and 12.2 % in oilseed rape, wheat and sunflower, respectively. Feral radish seed production ranged from 4,300 to 31,200, and 1000 to 4,700 seeds m-2 in winter crops and sunflower, respectively. Season-long feral radish interference can result in serious economic losses in oilseed rape, wheat and sunflower. The adverse impact of feral radish on the yield of winter and summer crops and the high feral radish seed and pods production suggests the need for the development and implementation of diverse and effective long-term weed management practices.

plant biology↗

bioRxiv2020

Ecological fitness cost associated with the AHAS Trp574Leu mutation in feral Raphanus sativus

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 throughout the life cycle of the weed feral radish (Raphanus sativus L.). Resistant and susceptible biotypes responded differently to light and water treatments in relation to germination and emergence. Under light exposure, the resistant biotype showed higher germination and emergence, but no differences were found in seed dormancy, germination in darkness and emergence from buried seeds or pods. The resistant biotype showed delayed and reduced seedling emergence relative to the susceptible biotype under rainfed conditions, but these differences between the biotypes were not detected in irrigated soil. The biotypes showed similar relative growth rates and vegetative biomass. However, under wheat interference, resistant plants had 36-46% less total above-ground biomass, 26-47% less seeds per plant, and 36-53% less plant yield than susceptible ones, and these differences were more evident at higher plant density. This study provides a better understanding of the ecological fitness cost associated with the AHAS Trp574Leu mutation in feral R. sativus. The fitness costs could reduce the frequency of the resistant allele in areas untreated with AHAS inhibiting herbicides.

evolutionary biology↗

bioRxiv2020

Maternal control of early life history traits affects overwinter survival and seedling phenotypes in sunflower (Helianthus annuus L.)

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 reciprocal crop-wild sunflower (Helianthus annuus L.) hybrids, we evaluated the maternal effects on emergence timing and seedling establishment in the field, and on seedling traits under controlled conditions. In the field, we evaluated reciprocal crop-wild hybrids between two wild populations with contrasting dormancy (the high dormant BAR and the low dormant DIA) and one cultivar (CROP) with low dormancy. Under controlled conditions, we evaluated reciprocal crop-wild hybrids between two wild populations (BAR and RCU) and one CROP under three contrasting temperature treatments. In the field, BAR overwintered as dormant seeds whereas DIA and CROP showed high autumn emergence ([~]50% of planted seeds), resulting in differential overwinter survival and seedling establishment in the spring. Reciprocal crop-wild hybrids resembled their female parents in emergence timing and success of seedling establishment. Under controlled conditions, we observed large maternal effects on most seedling traits across temperatures. Cotyledon size explained most of the variation in seedling traits, suggesting that the maternal effects on seed size have cascading effects on seedling traits. Maternal effects on early life history traits affect early plant survival and phenotypic variation of crop-wild hybrids, thus, they should be addressed in hybridization studies, especially those involving highly divergent parents like cultivated species and their wild ancestors.

plant biology↗