Polyphyletic origins of Brassica napus: new evidence based on organelle and nuclear RFLP analyses

Genome ◽  
1992 ◽  
Vol 35 (6) ◽  
pp. 992-1001 ◽  
Author(s):  
Keming Song ◽  
Thomas C. Osborn
Keyword(s):  
Brassica Napus ◽  
Phylogenetic Analyses ◽  
Molecular Taxonomy ◽  
Diploid Species ◽  
Evidence Based ◽  
Diploid Progenitor ◽  
Multiple Origins ◽  
Specialized Form ◽  
Almost All ◽  
New Evidence

Accessions representing a range of diversity in Brassica napus and their potential diploid progenitor species were analyzed using nuclear, chloroplast (ct), and mitochondrial (mt) RFLPs. Based on RFLPs of ctDNA and mtDNA, cytoplasmic genomes of the diploid species examined could be classified into four major types, represented by almost all B. rapa, Broccoletto (a specialized form of B. rapa), B. oleracea, and B. montana. Results from phylogenetic analyses of these data suggest that B. montana might be closely related to the prototype that gave rise to both cytoplasms of B. rapa and B. oleracea. The four major types of cytoplasms found in the diploid species were also observed in B. napus accessions. A majority of the cultivated B. napus examined contained a cytoplasm different from those of either B. rapa and B. oleracea. These B. napus accessions (designated M/N cytoplasm type) had the same chloroplast genome as that of B. montana and a unique mitochondrial genome that was somewhat intermediate between those of B. montana and B. rapa. These results strongly support the concept of multiple origins of B. napus and provide the first evidence that most cultivated forms of B. napus were derived from a cross in which a closely related ancestral species of B. rapa and B. oleracea was the maternal donor. Phylogenetic relationships based on nuclear RFLPs clearly separated B. napus accessions having different cytoplasm types, providing further evidence for multiple origins of B. napus. Brassica napus accessions having M/N type cytoplasm were clustered together as three subgroups: one contained oilseed cultivars from Canada, a second contained oilseed cultivars from Europe, and a third contained accessions of rutabaga.Key words: Brassica napus, molecular taxonomy, RFLP, chloroplast, mitochondrion.

scholarly journals Chloroplast phylogenomics in Camelina (Brassicaceae) reveals multiple origins of polyploid species and the maternal lineage of C. sativa

2022 ◽  
Vol 9 ◽  
Author(s):  
Jordan R Brock ◽  
Terezie Mandáková ◽  
Michael McKain ◽  
Martin A Lysak ◽  
Kenneth M Olsen
Keyword(s):  
Phylogenetic Analyses ◽  
Divergence Time ◽  
Diploid Species ◽  
Time Estimation ◽  
Polyploid Species ◽  
Chromosome Counts ◽  
Diploid Parent ◽  
Divergence Time Estimation ◽  
Multiple Origins ◽  
Chloroplast Genomes

Abstract The genus Camelina (Brassicaceae) comprises 7–8 diploid, tetraploid, and hexaploid species. Of particular agricultural interest is the biofuel crop, C. sativa (gold-of-pleasure or false flax), an allohexaploid domesticated from the widespread weed, C. microcarpa. Recent cytogenetics and genomics work has uncovered the identity of the parental diploid species involved in ancient polyploidization events in Camelina. However, little is known about the maternal subgenome ancestry of contemporary polyploid species. To determine the diploid maternal contributors of polyploid Camelina lineages, we sequenced and assembled 84 Camelina chloroplast genomes for phylogenetic analysis. Divergence time estimation was used to infer the timing of polyploidization events. Chromosome counts were also determined for 82 individuals to assess ploidy and cytotypic variation. Chloroplast genomes showed minimal divergence across the genus, with no observed gene-loss or structural variation. Phylogenetic analyses revealed C. hispida as a maternal diploid parent to the allotetraploid Camelina rumelica, and C. neglecta as the closest extant diploid contributor to the allohexaploids C. microcarpa and C. sativa. The tetraploid C. rumelica appears to have evolved through multiple independent hybridization events. Divergence times for polyploid lineages closely related to C. sativa were all inferred to be very recent, at only ~65 thousand years ago. Chromosome counts confirm that there are two distinct cytotypes within C. microcarpa (2n = 38 and 2n = 40). Based on these findings and other recent research, we propose a model of Camelina subgenome relationships representing our current understanding of the hybridization and polyploidization history of this recently-diverged genus.

scholarly journals Mining transcriptomic data to study the origins and evolution of a plant allopolyploid complex

2014 ◽  
Author(s):  
Aureliano Bombarely ◽  
Jeremy E Coate ◽  
Jeff J Doyle
Keyword(s):  
Population Genomics ◽  
Transcriptome Assembly ◽  
Phylogenetic Analyses ◽  
Diploid Species ◽  
Complex Problem ◽  
Common Mechanism ◽  
Chromosome Loss ◽  
Polyploid Species ◽  
Multiple Origins ◽  
Cultivated Soybean

Allopolyploidy combines two progenitor genomes in the same nucleus, and is a common mechanism for producing new species, especially in plants. Deciphering the origins of polyploid species is a complex problem, due to, among other things, extinct progenitors, multiple origins, gene flow between different polyploid populations, and loss of parental contributions through gene or chromosome loss. In this work, we studied three allopolyploid species in the genus Glycine, which includes the cultivated soybean (G. max). Previous work based on two nuclear sequences showed that these allopolyploids combine the genomes of extant diploid species in the G. tomentella complex. We use several phylogenetic and population genomics approaches to clarify the origin of these species using single nucleotide polymorphism data and a guided transcriptome assembly. The results support the hypothesis that each of the three polyploid species are fixed hybrids combining the homoeologous genomes of its two putative parents. Based on mapping to the soybean reference genome, there appear to be no large regions for which one homoeologous contribution is missing. Phylogenetic analyses of 27 selected transcripts using a coalescent approach also indicates multiple origins for G. tomentella polyploid species, and suggest that origins occurred within the last several hundred thousands years.

scholarly journals Mining transcriptomic data to study the origins and evolution of a plant allopolyploid complex

2014 ◽  
Author(s):  
Aureliano Bombarely ◽  
Jeremy E Coate ◽  
Jeff J Doyle
Keyword(s):  
Population Genomics ◽  
Transcriptome Assembly ◽  
Phylogenetic Analyses ◽  
Diploid Species ◽  
Complex Problem ◽  
Common Mechanism ◽  
Chromosome Loss ◽  
Polyploid Species ◽  
Multiple Origins ◽  
Cultivated Soybean

Allopolyploidy combines two progenitor genomes in the same nucleus, and is a common mechanism for producing new species, especially in plants. Deciphering the origins of polyploid species is a complex problem, due to, among other things, extinct progenitors, multiple origins, gene flow between different polyploid populations, and loss of parental contributions through gene or chromosome loss. In this work, we studied three allopolyploid species in the genus Glycine, which includes the cultivated soybean (G. max). Previous work based on two nuclear sequences showed that these allopolyploids combine the genomes of extant diploid species in the G. tomentella complex. We use several phylogenetic and population genomics approaches to clarify the origin of these species using single nucleotide polymorphism data and a guided transcriptome assembly. The results support the hypothesis that each of the three polyploid species are fixed hybrids combining the homoeologous genomes of its two putative parents. Based on mapping to the soybean reference genome, there appear to be no large regions for which one homoeologous contribution is missing. Phylogenetic analyses of 27 selected transcripts using a coalescent approach also indicates multiple origins for G. tomentella polyploid species, and suggest that origins occurred within the last several hundred thousands years.

Evidence-based regulation of labour migration in OECD countries: setting quotas, selection criteria, and shortage lists

2014 ◽  
Vol 11 (1) ◽  
pp. 11-22 ◽  
Author(s):  
Jonathan Chaloff
Keyword(s):  
Labour Market ◽  
Selection Criteria ◽  
Oecd Countries ◽  
Market Analysis ◽  
Multiple Criteria ◽  
Labour Migration ◽  
Evidence Based ◽  
Periodic Review ◽  
Market Data ◽  
Almost All

The growing complexity of selection criteria for discretionary labour migration in OECD countries has been accompanied by an expanded demand for labour market analysis and consultation with stakeholders. While some features of general or detailed criteria may be fixed in legislation, numerical quotas or targets, shortage lists, and multiple-criteria points-based systems are generally subject to periodic review and revision based on labour market data and consultation with stakeholders. Official government bodies have maintained co-ordination of this process, with varying degrees of externalization. In most countries expertise is internal, with recourse to external mandated bodies rare. In almost all cases, however, the process is designed to promote consensus around the policy while maintaining political control.

Comparative Analysis of Genetic and Morphological Variation within the Platanthera hyperborea Complex (Orchidaceae)

2020 ◽  
Vol 45 (4) ◽  
pp. 767-778
Author(s):  
Eranga Wettewa ◽  
Nick Bailey ◽  
Lisa E. Wallace
Keyword(s):  
North America ◽  
Diploid Species ◽  
Morphological Characters ◽  
Evolutionary Patterns ◽  
Founding Population ◽  
Multiple Origins ◽  
Geographic Structure ◽  
Species Complexes ◽  
Nuclear Its ◽  
Cryptic Taxa

Abstract—Species complexes present considerable problems for a working taxonomy due to the presence of intraspecific variation, hybridization, polyploidy, and phenotypic plasticity. Understanding evolutionary patterns using molecular markers can allow for a more thorough assessment of evolutionary lineages than traditional morphological markers. In this study, we evaluated genetic diversity and phylogenetic patterns among taxa of the Platanthera hyperborea (Orchidaceae) complex, which includes diploid (Platanthera aquilonis) and polyploid (Platanthera hyperborea, P. huronensis, and P. convallariifolia) taxa spanning North America, Greenland, Iceland, and Asia. We found that three floral morphological characters overlap among the polyploid taxa, but the diploid species has smaller flowers. DNA sequence variation in a plastid (rpL16 intron) and a nuclear (ITS) marker indicated that at least three diploid species have contributed to the genomes of the polyploid taxa, suggesting all are of allopolyploid origin. Platanthera convallariifolia is most like P. dilatata and P. stricta, whereas P. huronensis and P. hyperborea appear to have originated from crosses of P. dilatata and P. aquilonis. Platanthera huronensis, which is found across North America, has multiple origins and reciprocal maternal parentage from the diploid species. By contrast, P. hyperborea, restricted to Greenland and Iceland, appears to have originated from a small founding population of hybrids in which P. dilatata was the maternal parent. Geographic structure was found among polyploid forms in North America. The area of Manitoba, Canada appears to be a contact zone among geographically diverse forms from eastern and western North America. Given the geographic and genetic variation found, we recommend continued recognition of four green-flowered species within this complex, but caution that there may be additional cryptic taxa within North America.

scholarly journals Comparison on the Nutrient Plunder Capacity of Orychophragmus violaceus and Brassica napus L. Based on Electrophysiological Information

Horticulturae ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 206
Author(s):  
Cheng Zhang ◽  
Yue Su ◽  
Yanyou Wu ◽  
Haitao Li ◽  
Ying Zhou ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Orychophragmus Violaceus ◽  
Nutrient Metabolism ◽  
Brassica Napus L ◽  
Adaptive Mechanisms ◽  
Capacitive Reactance ◽  
Time Determination ◽  
Almost All ◽  
First Time

The nutrient metabolism, growth and development of plants are strongly affected by its nutrient plunder, and plants have different adaptive mechanisms to low-nutrient environments. The electrophysiological activities involve almost all life processes of plants. In this study, the active transport flow of nutrient (NAF) and nutrient plunder capacity (NPC) of plants were defined based on leaf intrinsic impedance (IZ), capacitive reactance (IXc), inductive reactance (IXL) and capacitance (IC) to evaluate the nutrient plunder capacity of plants for the first time. The results indicate that Orychophragmus violaceus had higher (p < 0.01) NPC and IC and lower (p < 0.01) IR, IXc, IXL and IZ as compared to Brassica napus L., which supports a superior ion affinity and that it could be better adapted to low-nutrient environments. UAF and NPC of plants exhibited good correlations with crude protein, crude ash and water content, and precisely revealed the plunder capacity and adaptive strategies of plants to nutrients. The present work highlights that O. violaceus had superior NPC and ion affinity compared with B. napus, and provided a novel, rapid, reliable method based on the plant’s electrophysiological information for real-time determination of the nutrient plunder capacity of plants.

scholarly journals Ethnomedicinal Uses of Honeybee Products in Lithuania: The First Analysis of Archival Sources

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Zivile Pranskuniene ◽  
Jurga Bernatoniene ◽  
Zenona Simaitiene ◽  
Andrius Pranskunas ◽  
Tauras Mekas
Keyword(s):  
Folk Medicine ◽  
Evidence Based ◽  
Ethnomedicinal Uses ◽  
New Evidence ◽  
Preparation Techniques ◽  
Standardization Methods ◽  
Different Parts

Lithuania has old ethnomedicine traditions, consisting of many recipes with herbal, animal, and mineral original ingredients. All these findings were mostly collected in Lithuanian language, often in local community’s dialects, and stored only in archives. We analyzed archival sources about honeybee and its products used for medicinal purposes dated from 1886 till 1992 in different parts of Lithuania. We systematized and presented the most important information about bees and their products: indication for usage, ingredients used in the recipe, their preparation techniques, and application for therapeutic purposes. Researchers in Lithuania are now looking for new evidence based indications and preparation and standardization methods of bee products. Archival sources are a foundation for studies in Lithuania. The results can be integrated into scientifically approved folk medicine practices into today’s healthcare.

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