RESUMEN
BACKGROUND: Hybridization and polyploidization can be major mechanisms for plant evolution and speciation. Thus, the process of polyploidization and evolutionary history of polyploids is of widespread interest. The species in Elymus L. sensu lato are allopolyploids that share a common St genome from Pseudoroegneria in different combinations with H, Y, P, and W genomes. But how the St genome evolved in the Elymus s. l. during the hybridization and polyploidization events remains unclear. We used nuclear and chloroplast DNA-based phylogenetic analyses to shed some light on this process. RESULTS: The Maximum likelihood (ML) tree based on nuclear ribosomal internal transcribed spacer region (nrITS) data showed that the Pseudoroegneria, Hordeum and Agropyron species served as the St, H and P genome diploid ancestors, respectively, for the Elymus s. l. polyploids. The ML tree for the chloroplast genes (matK and the intergenic region of trnH-psbA) suggests that the Pseudoroegneria served as the maternal donor of the St genome for Elymus s. l. Furthermore, it suggested that Pseudoroegneria species from Central Asia and Europe were more ancient than those from North America. The molecular evolution in the St genome appeared to be non-random following the polyploidy event with a departure from the equilibrium neutral model due to a genetic bottleneck caused by recent polyploidization. CONCLUSION: Our results suggest the ancient common maternal ancestral genome in Elymus s. l. is the St genome from Pseudoroegneria. The evolutionary differentiation of the St genome in Elymus s. l. after rise of this group may have multiple causes, including hybridization and polyploidization. They also suggest that E. tangutorum should be treated as C. dahurica var. tangutorum, and E. breviaristatus should be transferred into Campeiostachys. We hypothesized that the Elymus s. l. species origined in Central Asia and Europe, then spread to North America. Further study of intraspecific variation may help us evaluate our phylogenetic results in greater detail and with more certainty.
Asunto(s)
Evolución Biológica , ADN de Plantas/genética , Elymus/genética , Proteínas de Plantas/genética , Núcleo Celular/genética , Proteínas de Cloroplastos/genética , Proteínas de Cloroplastos/metabolismo , ADN de Cloroplastos/genética , ADN de Cloroplastos/metabolismo , ADN de Plantas/metabolismo , Elymus/metabolismo , Datos de Secuencia Molecular , Filogenia , Proteínas de Plantas/metabolismo , Análisis de Secuencia de ADNRESUMEN
Ribosomal ITS polymorphism and its ancestral genome origin of polyploid Leymus were examined to infer the evolutionary outcome of rDNA gene following allopolyploid speciation and to elucidate the geographic pattern of ITS variation. The results demonstrated that different polyploids have experienced varying fates, including maintenance or homogenization of divergent arrays, occurrence of chimeric repeats and potential pseudogenes. Our data suggested that (1) the Ns, P/F, and St genomic types in Leymus were originated from Psathyrostachys, Agropyron/Eremopyrum, and Pseudoroegneria, respectively; (2) the occurrence of a higher proportion of Leymus species with predominant uniparental rDNA type might associate with the segmental allopolyploid origin, nucleolar dominance of alloploids, and rapid radiation of Leymus; (3) maintenance of multiple parental ITS types in allopolyploid might result from long generation times associated to vegetative multiplication, number and chromosomal location of ribosomal loci and/or recurrent hybridization; (4) the rDNA genealogical structure of Leymus species might associate with the geographic origins; and (5) ITS sequence clade shared by Leymus species from Central Asia, North America, and Nordic might be an outcome of ancestral ITS homogenization. Our results shed new light on understanding evolutionary outcomes of rDNA following allopolyploid speciation and geographic isolation.
Asunto(s)
ADN Ribosómico/genética , Filogenia , Poaceae/genética , Poliploidía , Genoma de Planta , Poaceae/clasificación , Análisis de Secuencia de ADNRESUMEN
To estimate the origin and genomic relationships of the polyploid species within Elymus L. sensu lato, two unlinked single-copy nuclear gene (Acc1 and Pgk1) sequences of eighteen tetraploids (StH and StY genomes) and fourteen hexaploids (StStH, StYP, StYH, and StYW genomes) were analyzed with those of 35 diploid taxa representing 18 basic genomes in Triticeae. Sequence and phylogenetic analysis suggested that: (1) the St, H, W, and P genomes were donated by Pseudoroegneria, Hordeum, Australopyrum, and Agropyron, respectively, while the Y genome is closely related to the Xp genome in Peridictyon sanctum; (2) different hexaploid Elymus s.l. species may derived their StY genome from different StY genome tetraploid species via independent origins; (3) due to incomplete lineage sorting and/or hybridization events, the genealogical conflict between the two gene trees suggest introgression involving some Elymus s.l. species, Pseudoroegneria, Agropyron and Aegilops/Triticum; (4) it is reasonable to recognize the StH genome species as Elymus sensu stricto, the StY genome species as Roegneria, the StYW genome species as Anthosachne, the StYH genome species as Campeiostachys, and the StYP genome species as Kengyilia. The occurrence of multiple origin and introgression could account for the rich diversity and ecological adaptation of Elymus s.l. species.
Asunto(s)
Elymus/clasificación , Evolución Molecular , Genoma de Planta , Filogenia , Teorema de Bayes , Núcleo Celular/genética , ADN de Plantas/genética , Elymus/genética , Funciones de Verosimilitud , Poliploidía , Alineación de Secuencia , Análisis de Secuencia de ADNRESUMEN
This study is to investigate the protective effect of longistyline A against corticosterone-induced neurotoxicity in PC12 cells. While PC12 cells were exposed to 100 micromol x L(-1) corticosterone for 48 h, cell survival rate was reduced and lactate dehydrogenase (LDH) release increased. In parallel, corticosterone caused significant elevations of DNA fragmentation, [Ca2+]i and caspase-3 activity. However, when the PC12 cells were incubated with longistyline A (4.0, 8.0 and 16.0 micromol x L(-1)) in the presence of 100 micromol x L(-1) corticosterone for 48 h, the effects were evidently alleviated, but dose-dependent manner was not obvious. In summary, longistyline A could generate a neuroprotective effect against corticosterone-induced neurotoxicity in PC12 cells possibly by decreasing [Ca2+]i and caspase-3 activity.
Asunto(s)
Calcio/metabolismo , Caspasa 3/metabolismo , Supervivencia Celular/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Fenoles/farmacología , Animales , Cajanus/química , Corticosterona/toxicidad , Fragmentación del ADN/efectos de los fármacos , L-Lactato Deshidrogenasa/metabolismo , Estructura Molecular , Fármacos Neuroprotectores/aislamiento & purificación , Células PC12 , Fenoles/aislamiento & purificación , Hojas de la Planta/química , Plantas Medicinales/química , RatasRESUMEN
BCAKGROUND: The dry root and rhizome of Salvia miltiorrhiza are used to treat cardiovascular diseases, chronic pain, and thoracic obstruction over 2000 years in Asian countries. For high quality, Sichuan Zhongjiang is regarded as the genuine producing area of S. miltiorrhiza. Given its abnormal pollen development, S. miltiorrhiza from Sichuan (S.m.-SC) relies on root reproduction and zymad accumulation; part of diseased plants present typical viral disease symptoms and seed quality degeneration. This study aim to detected unknown viruses from mosaic-diseased plants and establish a highly efficient virus-free regeneration system to recover germplasm properties. RESULTS: Tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV) were detected from mosaic-diseased plants. Primary apical meristem with two phyllo podium in 0.15-0.5 mm peeled from diseased plants were achieved 73.33% virus-free rate. The results showed that the medium containing MS, 0.5 mg/L 6-BA, 0.1 mg/L NAA, 0.1 mg/L GA3, 30 g/L sucrose and 7.5 g/L agar can achieve embryonic-tissue (apical meristem, petiole and leaf callus) high efficient organogenesis. For callus induction, the optimal condition was detected on the medium containing MS, 2 mg/L TDZ, 0.1 mg/L NAA by using secondary petiole of virus-free plants under 24 h dark/d condition for 21 d. The optimal system for root induction was the nutrient solution with 1/2 MS supplemented with 1 mg/L NAA. After transplant, the detection of agronomic metric and salvianolic acid B content confirmed the great germplasm properties of S.m.-SC virus-free plants. CONCLUSIONS: A highly efficient virus-free regeneration system of S.m.-SC was established based on the detected viruses to recover superior seed quality. The proposed system laid support to control disease spread, recover good germplasm properties in S.m.-SC.
RESUMEN
BACKGROUND: Single- and low- copy genes are less likely subject to concerted evolution, thus making themselves ideal tools for studying the origin and evolution of polyploid taxa. Leymus is a polyploid genus with a diverse array of morphology, ecology and distribution in Triticeae. The genomic constitution of Leymus was assigned as NsXm, where Ns was presumed to be originated from Psathyrostachys, while Xm represented a genome of unknown origin. In addition, little is known about the evolutionary history of Leymus. Here, we investigate the phylogenetic relationship, genome donor, and evolutionary history of Leymus based on a single-copy nuclear Acc1 gene. RESULTS: Two homoeologues of the Acc1 gene were isolated from nearly all the sampled Leymus species using allele-specific primer and were analyzed with those from 35 diploid taxa representing 18 basic genomes in Triticeae. Sequence diversity patterns and genealogical analysis suggested that (1) Leymus is closely related to Psathyrostachys, Agropyron, and Eremopyrum; (2) Psathyrostachys juncea is an ancestral Ns-genome donor of Leymus species; (3) the Xm genome in Leymus may be originated from an ancestral lineage of Agropyron and Eremopyrum triticeum; (4) the Acc1 sequences of Leymus species from the Qinghai-Tibetan plateau are evolutionarily distinct; (5) North America Leymus species might originate from colonization via the Bering land bridge; (6) Leymus originated about 11-12MYA in Eurasia, and adaptive radiation might have occurred in Leymus during the period of 3.7-4.3 MYA and 1.7-2.1 MYA. CONCLUSION: Leymus species have allopolyploid origin. It is hypothesized that the adaptive radiation of Leymus species might have been triggered by the recent upliftings of the Qinghai-Tibetan plateau and subsequent climatic oscillations. Adaptive radiation may have promoted the rapid speciation, as well as the fixation of unique morphological characters in Leymus. Our results shed new light on our understanding of the origin of Xm genome, the polyploidization events and evolutionary history of Leymus that could account for the rich diversity and ecological adaptation of Leymus species.
Asunto(s)
Acetil-CoA Carboxilasa/genética , Evolución Molecular , Filogenia , Poaceae/genética , Secuencia de Bases , ADN de Plantas/genética , Genoma de Planta , Datos de Secuencia Molecular , Plastidios/genética , Poaceae/enzimología , Alineación de Secuencia , Análisis de Secuencia de ADNRESUMEN
The contents of trace elements, including copper, zinc, iron, magnesium, calcium, chromium, lead, molybdenum, manganese, and cadmium in Chinese traditional herb S. miltiorrhiza and its relative species such as S. miltiorrhiza f. alba, S. evansiana, S. yunnanensis, S. przewarlskii, S. cavaleriei, S. cavaleriei var. simplicifolia, S. roborowskii, S. omeiana, S. tricuspis, S. brevilabra and S. cynica were determined by atomic absorption spectroscopy. The principal components analysis of SPSS was applied to the study of characteristic elements in S. miltiorrhiza and its relative species. Three principal components which accounted for 79.3% of total variance were extracted from the original data. The first factor accounted for 49.6% of the total variance, which means that iron, manganese, copper, zinc, cadmium and lead are the characteristic elements in S. miltiorrhiza and its relative species. The results of cluster analysis show that the samples could cluster reasonably into two groups. The samples of S. miltiorrhiza from different regions were classified into one group except S. miltiorrhiza from Zhejiang and S. miltiorrhiza f. alba. The other Salvia species were classified into another group except S. cavaleriei. The S. miltiorrhiza and other Salvia species can be distinguished by this method, whose accuracy of classification is 90%. The cluster analysis based on the contents of trace element in S. miltiorrhiza and its relative species provided a quick, accurate and simple method for authentication of herb Salvia miltiorrhiza.
Asunto(s)
Análisis por Conglomerados , Análisis de Componente Principal/métodos , Salvia miltiorrhiza/química , Oligoelementos/análisis , Cadmio/análisis , Calcio/análisis , Cromo/análisis , Cobre/análisis , Hierro/análisis , Magnesio/análisis , Manganeso/análisis , Espectrofotometría Atómica/métodos , Zinc/análisisRESUMEN
OBJECTIVE: To explore genetic relationships of the 39 materials in six species of Curcuma. METHOD: The peroxidase isozyme (POD) and esterase isozyme (EST) were studied using vertical slab polyacrylamide gel electrophoresis (PAGE) technique, and the zymograms were analyzed using the software of NTSYSpc2. 1. RESULT: The interspecific zymogramatic differences were obvious. Each species possessed its own specific zymogram distinguishing form the others. In the analysis of EST isozyme, C. phaeocaulis, C. wenyujin, C. kwangsiensis and C. chuanhuangjiang had their own specific zymogram. In the analysis of POD isozyme, just C. phaeocaulis and C. kwangsiensis had their specific zymogram. CONCLUSION: The genetic relationships are not associated with the geographical distributions and the genetic relationship between C. longa and C. sichuanensis are very close.
Asunto(s)
Curcuma/enzimología , Curcuma/genética , Esterasas/análisis , Peroxidasa/análisis , Análisis por Conglomerados , Curcuma/clasificación , Electroforesis en Gel de Poliacrilamida , Esterasas/genética , Isoenzimas/análisis , Isoenzimas/genética , Peroxidasa/genética , Filogenia , Especificidad de la EspecieRESUMEN
Using the method of double color fluorescence in situ hybridization (FISH), we had analyzed Triticum polonicum L. and T. turgidum L. cv. Ailanmai with the probes of 45S rDNA and 5S rDNA. The results indicated that there were highly consistent in T. polonicum L. High and T. turgidum L. cv. Ailanmai, both having four 45S rDNA loci and six 5S rDNA loci. In T. polonicum L. Dwarf, there were also four 45S rDNA loci, the same as that in T. polonicum L. High and T. turgidum L. cv. Ailanmai, but there were eight 5S rDNA loci. At the same time, we discussed the reason of interspecific and intraspecific variation of the two types of rDNA in locus number and location between T. polonicum L. and T. turgidum L. cv. Ailanmai.
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ADN Ribosómico/análisis , Hibridación Fluorescente in Situ/métodos , ARN Ribosómico 5S/análisis , Triticum/genética , Mapeo Cromosómico , Hibridación Genética , Cariotipificación , ARN Ribosómico/análisis , ARN Ribosómico/genética , ARN Ribosómico 5S/genética , Triticum/clasificaciónRESUMEN
PCR-RFLP of Plasmon on 23 species of Roegneria, Elymus, Hystrix and Kengyilia and 1 outgroup (Triticum aestivum L.) was carried out. The segments amplified with 3 cpDNA and 3 mtDNA universal primers were digested by 15 restriction endonucleases. Among 329 bands produced, 304 were polymorphic (92.4%). PCR-RFLP results showed that polymorphisms existed between the four genera and between the species in Roegneria, Elymus, Hystrix and Kengyilia, and genetic similarity coefficient was high. Roegneria grandis, R. aristiglumis, R. elytrigioides, R. alashanica and R. magnicaespes were grouped, while R. caucasica, R. ciliaris, R. amurensis and R. japonensis clustered together. Species of Kengyilia clustered independently. Five species of Elymus, 3 of Hystrix and Roegneria kamoji grouped together. The results suggested Kengyilia was a valid genus. As more cytological and molecular data are available, the taxonomic status of Roegneria, Elymus and Hystrix will be recognized.
Asunto(s)
Genoma de Planta , Poaceae/genética , Polimorfismo Genético , Cartilla de ADN , ADN de Cloroplastos , ADN Mitocondrial , Elymus , Filogenia , Reacción en Cadena de la Polimerasa/métodos , Polimorfismo de Longitud del Fragmento de Restricción , Especificidad de la EspecieRESUMEN
OBJECTIVE: To study the numbers of chromosome in Chinese herb Salvia miltiorrhiza from 7 provinces in China, and S. flava as well as S. evansiana from Yunnan province in China. METHOD: The young root was treated with the mixture of ice and water for 24 h, fixed with Carony's fixative for 6-12 h. After differentiating for 10-12 min with 1 mol x L(-1) hydrochloric acid at 60 'C and staining with carbol fuchsin,the section was observed under microscope. RESULT: Chromosome numbers of S. miltiorrhiza and S.flava were 2n = 2x = 16. The numbers of S. evansiana were 2n = 4x = 32. The basic numbers of the chromosomes were x = 8. And tetraploids were observed in S. miltiorrhiza from Sichuan provices and Shandong provices. CONCLUSION: The basic number of the chromosomes are x = 8. The chromosome numbers of S. miltiorrhiza, S.flava and S. evansiana are 16,16 and 32 respectively. As the chromosomes are the small or micro-small ones, it is difficult to use them for karyotype.
Asunto(s)
Cromosomas de las Plantas/genética , Plantas Medicinales/genética , Salvia miltiorrhiza/genética , Diploidia , Raíces de Plantas/genética , Poliploidía , Salvia miltiorrhiza/clasificación , Especificidad de la EspecieRESUMEN
OBJECTIVE: To study the yield of different Houttuynia cordata and the changing regularity of their main officinal components in different periods, and provide a basis for harvesting in good time and breeding new varieties. METHOD: The main officinal composition and wet weight of overground parts per acreage of different accessions were determined periodically. The plot yields were tested when harvested and analyzed by analysis of variance. RESULT: The difference of the yields of different accessions was significant. The varying tendency of the content of main officinal component methyl nonyl ketone and its total content per acreage of different accessions were different. CONCLUSION: The integrate characters of Qionglai and Wangyu wild accessions are relatively better, worthy to be widely applied in production.
Asunto(s)
Medicamentos Herbarios Chinos/análisis , Plantas Medicinales , Saururaceae , China , Ecosistema , Houttuynia , Componentes Aéreos de las Plantas/química , Plantas Medicinales/anatomía & histología , Plantas Medicinales/química , Plantas Medicinales/crecimiento & desarrollo , Saururaceae/anatomía & histología , Saururaceae/química , Saururaceae/crecimiento & desarrollo , Estaciones del Año , Especificidad de la EspecieRESUMEN
Polysaccharides were extracted from Salvia miltiorrhiza Bunge using response surface methodology (RSM) with ultrasonication. A Box-Behnken design was used to optimize the extraction parameters to maximize the polysaccharide extraction yield. The polysaccharide SMP-U1 was isolated and characterized; then the antioxidant and antiproliferation activities were evaluated in vitro. The modified optimal conditions were an ultrasonic power of 180 W, an extraction temperature of 54°C, and an extraction time of 32 min, achieving an extraction yield of 40.54±0.25%. The results indicate that SMP-U1 has significant antioxidant activity, scavenging the free radical 2,2-diphenyl-1-picrylhydrazyl. It has also exhibited effect on the proliferation of human breast carcinoma cells Bcap-37 and human esophageal carcinoma cells Eca-109, especially at a concentration of 0.30 mg/mL. In conclusion, SMP-U1 has remarkable in vitro antioxidant and antiproliferation activity, and has potential for application as a natural antioxidant or antitumor agent.
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Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/farmacología , Antioxidantes/química , Antioxidantes/farmacología , Extractos Vegetales/química , Polisacáridos/química , Salvia miltiorrhiza/química , Análisis de Varianza , Antineoplásicos Fitogénicos/aislamiento & purificación , Antioxidantes/aislamiento & purificación , Carbohidratos/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Depuradores de Radicales Libres/química , Depuradores de Radicales Libres/farmacología , Humanos , Peso Molecular , Oxidación-Reducción/efectos de los fármacos , Extractos Vegetales/aislamiento & purificación , Proteínas de Plantas/química , Polisacáridos/aislamiento & purificación , Polisacáridos/farmacología , Espectroscopía Infrarroja por Transformada de Fourier , Ácidos Urónicos/químicaRESUMEN
An effective DNA marker for authenticating the genus Salvia was screened using seven DNA regions (rbcL, matK, trnL-F, and psbA-trnH from the chloroplast genome, and ITS, ITS1, and ITS2 from the nuclear genome) and three combinations (rbcL+matK, psbA-trnH+ITS1, and trnL-F+ITS1). The present study collected 232 sequences from 27 Salvia species through DNA sequencing and 77 sequences within the same taxa from the GenBank. The discriminatory capabilities of these regions were evaluated in terms of PCR amplification success, intraspecific and interspecific divergence, DNA barcoding gaps, and identification efficiency via a tree-based method. ITS1 was superior to the other marker for discriminating between species, with an accuracy of 81.48%. The three combinations did not increase species discrimination. Finally, we found that ITS1 is a powerful barcode for identifying Salvia species, especially Salvia miltiorrhiza.
Asunto(s)
ADN de Cloroplastos/genética , ADN Ribosómico/genética , Salvia/genética , Composición de Base , Código de Barras del ADN Taxonómico , ADN Intergénico/genética , ADN de Plantas/genética , Genes de Plantas , Sitios Genéticos , Marcadores Genéticos , Variación Genética , Genoma del Cloroplasto , Modelos Genéticos , Análisis de Secuencia de ADN , Estadísticas no ParamétricasRESUMEN
Single- and low-copy genes are less likely to be subject to concerted evolution. Thus, they are appropriate tools to study the origin and evolution of polyploidy plant taxa. The plastid 3-phosphoglycerate kinase gene (Pgk-1) sequences from 44 accessions of Triticum and Aegilops, representing diploid, tetraploid, and hexaploid wheats, were used to estimate the origin of Triticum petropavlovskyi. Our phylogenetic analysis was carried out on exon+intron, exon and intron sequences, using maximum likelihood, Bayesian inference and haplotype networking. We found the D genome sequences of Pgk-1 genes from T. petropavlovskyi are similar to the D genome orthologs in T. aestivum, while their relationship with Ae. tauschii is more distant. The A genome sequences of T. petropavlovskyi group with those of T. polonicum, but its Pgk-1 B genome sequences to some extent diverge from those of other species of Triticum. Our data do not support for the origin of T. petropavlovskyi either as an independent allopolyploidization event between Ae. tauschii and T. polonicum, or as a monomendelian mutation in T. aestivum. We suggest that T. petropavlovskyi originated via spontaneous introgression from T. polonicum into T. aestivum. The dating of divergence among T. polonicum, T. petropavlovskyi, T. carthlicum, T. turgidum, and T. compactum indicates an age of 0.78 million years [corrected].
Asunto(s)
Evolución Molecular , Fosfoglicerato Quinasa/genética , Proteínas de Plantas/genética , Triticum/genética , Teorema de Bayes , Calibración , ADN de Plantas/metabolismo , Exones , Genoma de Planta , Genotipo , Haplotipos , Intrones , Funciones de Verosimilitud , Filogenia , Polimorfismo de Longitud del Fragmento de Restricción , Análisis de Secuencia de ADN , Especificidad de la Especie , Factores de Tiempo , Triticum/enzimologíaRESUMEN
The level and pattern of nucleotide variation in duplicate gene provide important information on the evolutionary history of polyploids and divergent process between homoeologous loci within lineages. Kengyilia is a group of allohexaploid species with the StYP genomic constitutions in the wheat tribe. To investigate the evolutionary dynamics of the Pgk1 gene in Kengyilia and its diploid relatives, three copies of Pgk1 homoeologues were isolated from all sampled hexaploid Kengyilia species and analyzed with the Pgk1 sequences from 47 diploid taxa representing 18 basic genomes in Triticeae. Sequence diversity patterns and genealogical analysis suggested that (1) Kengyilia species from the Central Asia and the Qinghai-Tibetan plateau have independent origins with geographically differentiated P genome donors and diverged levels of nucleotide diversity at Pgk1 locus; (2) a relatively long-time sweep event has allowed the Pgk1 gene within Agropyron to adapt to cold climate triggered by the recent uplifts of the Qinghai-Tibetan Plateau; (3) sweep event and population expansion might result in the difference in the d(N)/d(S) value of the Pgk1 gene in allopatric Agropyron populations, and this difference may be genetically transmitted to Kengyilia lineages via independent polyploidization events; (4) an 83 bp MITE element insertion has shaped the Pgk1 loci in the P genome lineage with different geographical regions; (5) the St and P genomes in Kengyilia were donated by Pseudoroegneria and Agropyron, respectively, and the Y genome is closely related to the Xp genome of Peridictyon sanctum. The interplay of evolutionary forces involving diverged natural selection, population expansion, and transposable events in geographically differentiated P genome donors could attribute to geographical differentiation of Kengyilia species via independent origins.
Asunto(s)
Diploidia , Evolución Molecular , Genes de Plantas/genética , Fosfoglicerato Quinasa/genética , Poaceae/enzimología , Poaceae/genética , Poliploidía , Secuencia de Bases , Teorema de Bayes , Calibración , Funciones de Verosimilitud , Datos de Secuencia Molecular , Filogenia , Polimorfismo Genético , Selección Genética , Análisis de Secuencia de ADNRESUMEN
The phylogenetic relationships of 15 taxa from Hystrix and the related genera Leymus (NsXm), Elymus (StH), Pseudoroegneria (St), Hordeum (H), Psathyrostachys (Ns), and Thinopyrum (E) were examined by using the Giemsa C-banded karyotype. The Hy. patula C-banding pattern was similar to those of Elymus species, whereas C-banding patterns of the other Hystrix species were similar to those of Leymus species. The results suggest high genetic diversity within Hystrix, and support treating Hy. patula as E. hystrix L., and transferring Hy. coreana, Hy. duthiei ssp. duthiei and Hy. duthiei ssp. longearistata to the genus Leymus. On comparing C-banding patterns of Elymus species with their diploid ancestors (Pseudoroegneria and Hordeum), there are indications that certain chromosomal re-arrangements had previously occurred in the St and H genomes. Furthermore, a comparison of the C-banding patterns of the Hystrix and Leymus species with the potential diploid progenitors (Psathyrostachys and Thinopyrum) suggests that Hy. coreana and some Leymus species are closely related to the Ns genome of Psathyrostachys, whereas Hy. duthiei ssp. duthiei, Hy. duthiei ssp. longearistata and some of the Leymus species have a close relationship with the E genome. The results suggest a multiple origin of the polyploid genera Hystrix and Leymus.
RESUMEN
To investigate the phylogenetic relationships of polyploid Leymus (Poaceae: Triticeae), sequences of the nuclear rDNA internal transcribed spacer region (ITS) were analyzed for 34 Leymus accessions representing 25 species, together with three Psathyrostachys species (Ns genome), two Pseudoroegneria (St genome) species, Lophopyrum elongatum (E(e) genome), and Thinopyrum bessarabicum (E(b) genome). The phylogenetic analyses (maximum likelihood and Bayesian inference) supported two major clades, one including 21 Leymus species and three Psathyrostachys species, the other with nine Leymus species and four diploid species. The ITS RNA secondary structure of the Leymus species was compared with that of their putative diploid donor. It is suggested that (1) the species from the same areas or neighboring geographic regions are closely related to each other; (2) L. coreanus, L. duthiei, L. duthiei var. longearistatus, and L. komarovii are closely related to other Leymus species, and it is reasonable to transfer these species from the genus Hystrix to Leymus; (3) the ITS sequences of Leymus are evolutionarily distinct; (4) the different Leymus species and different distribution of a species derived their Ns genome from different Psathyrostachys species; and (5) there is a close relationship among Leymus, Pseudoroegneria, Lophopyrum, and Thinopyrum, but it is difficult to presume that the St, E(e), and E(b) genome may be the Xm genome donor of the Leymus species.
Asunto(s)
Núcleo Celular/metabolismo , ADN Intergénico/genética , ADN Ribosómico/genética , Triticum/genética , Secuencia de Bases , Teorema de Bayes , Genes de Plantas , Genoma , Genoma de Planta , Funciones de Verosimilitud , Modelos Genéticos , Datos de Secuencia Molecular , Conformación de Ácido Nucleico , Filogenia , ARN/genéticaRESUMEN
Genomic constitutions of three taxa of Hystrix Moench, H. patula, H. duthiei ssp. duthiei and H. duthiei ssp. longearistata, were examined by meiotic pairing behavior and genomic in-situ hybridization. Meiotic pairing in hybrids of H. patula x Pseudoroegneria spicata (St), H. patula x Elymus wawawaiensis (StH), H. patula x H. duthiei ssp. longearistata, H. patula x Psathyrostachys huashanica (Ns ( h )), H. duthiei ssp. duthiei x Psa. huashanica, H. duthiei ssp. longearistata x Psa. huashanica, Leymus multicaulis (NsXm) x H. duthiei ssp. longearistata averaged 6.53, 12.83, 1.32, 0.29, 5.18, 5.11 and 10.47 bivalents per cell, respectively. The results indicate that H. patula has the StH genome and H. duthiei ssp. duthiei and H. duthiei ssp. longearistata have the NsXm genome. Results of genomic in-situ hybridization analysis strongly supported the chromosome pairing data; therefore it is concluded that the type species of Hystrix, H. patula, should be included in Elymus, and that H. duthiei ssp. duthiei and H. duthiei ssp. longearistata should be transferred to Leymus.
Asunto(s)
Emparejamiento Cromosómico , Cromosomas de las Plantas , Genoma de Planta , Poaceae/genética , Cruzamientos Genéticos , Hibridación in Situ , Meiosis , Especificidad de la EspecieRESUMEN
The phylogenetic relationships of 15 taxa from Hystrix and the related genera Leymus (NsXm), Elymus (StH), Pseudoroegneria (St), Hordeum (H), Psathyrostachys (Ns), and Thinopyrum (E) were examined by using the Giemsa C-banded karyotype. The Hy. patula C-banding pattern was similar to those of Elymus species, whereas C-banding patterns of the other Hystrix species were similar to those of Leymus species. The results suggest high genetic diversity within Hystrix, and support treating Hy. patula as E. hystrix L., and transferring Hy. coreana, Hy. duthiei ssp. duthiei and Hy. duthiei ssp. longearistata to the genus Leymus. On comparing C-banding patterns of Elymus species with their diploid ancestors (Pseudoroegneria and Hordeum), there are indications that certain chromosomal re-arrangements had previously occurred in the St and H genomes. Furthermore, a comparison of the C-banding patterns of the Hystrix and Leymus species with the potential diploid progenitors (Psathyrostachys and Thinopyrum) suggests that Hy. coreana and some Leymus species are closely related to the Ns genome of Psathyrostachys, whereas Hy. duthiei ssp. duthiei, Hy. duthiei ssp. longearistata and some of the Leymus species have a close relationship with the E genome. The results suggest a multiple origin of the polyploid genera Hystrix and Leymus.