RESUMO
Members of the 14-3-3 family of proteins are conserved regulatory proteins that are widely found in eukaryotes and play crucial roles in diverse physiological processes, including responses to different stresses. Although genome-wide analysis of 14-3-3 proteins has been performed in a few plant species, it has not been performed in switchgrass. In this study, we identified 21 switchgrass 14-3-3 proteins (designated PvGF14a to PvGF14u) and examined genes for improved stress tolerance in this species. A phylogenetic tree was constructed to demonstrate that PvGF14 proteins can be divided into six groups, and that PvGF14 proteins belonging to each class exhibit similar gene structure. A phylogenetic analysis of PvGF14 proteins among switchgrass, Arabidopsis, and rice was conducted. Ten PvGF14 proteins were found to be orthologous to several abiotic stresses, and these were particularly responsive proteins in Arabidopsis and rice. Tissue-specific expression profiles showed that PvGF14a, PvGF14k, PvGF14l, and PvGF14m may play significant roles in the regulation of lignin metabolism, and that PvGF14r may participate in flower development. Taken together, these data suggest that PvGF14 proteins may be involved in various biosynthesis.
Assuntos
Proteínas 14-3-3/genética , Proteínas 14-3-3/metabolismo , Panicum/crescimento & desenvolvimento , Panicum/metabolismo , Mapeamento Cromossômico , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Família Multigênica , Especificidade de Órgãos , Panicum/genética , Filogenia , Estresse FisiológicoRESUMO
Roegneria kamoji Ohwi is an excellent forage grass due to its high feeding value and high resistance to some biotic and abiotic stresses. However, the start codon targeted (SCoT) polymorphism has not been conducted on R. kamoji. In this study, an orthogonal L16 (45) design was employed to investigate the effects of five factors (Mg2+, dNTPs, Taq DNA polymerase, primer, and template DNA) on the polymerase chain reaction (PCR) to determine the optimal SCoT-PCR system for R. kamoji. The results showed that the most suitable conditions for SCoT-PCR in R. kamoji included 1.5 mM Mg2+, 0.15 mM dNTPs, 1.0 U Taq DNA polymerase, 0.4 pM primer, and 40 ng template DNA. SCoT primers 39 and 41 were used to verify the stability of the optimal reaction system, and amplification bands obtained from diverse samples were found to be clear, rich, and stable in polymorphisms, indicating that this reaction system can be used for SCoT-PCR analysis of R. kamoji. We have developed a simple and rapid way to study the mutual effects of factors and to obtain positive results through the use of an orthogonal design L16 (45) to optimize the SCoT-PCR system. This method may provide basic information for molecular marker-assisted breeding and analyses of genetic diversity in R. kamoji.
Assuntos
Códon de Iniciação/genética , Poaceae/genética , Reação em Cadeia da Polimerase/métodos , Polimorfismo Genético , Primers do DNA/genética , Variação Genética , Poaceae/crescimento & desenvolvimentoRESUMO
The effects of 5 factors (template DNA, Mg(2+), dNTPs, Taq DNA polymerase, and primer) on the polymerase chain reaction (PCR) were investigated to optimize the start codon targeted polymor-phism (SCoT)-PCR system of Dactylis glomerata L., using an orthogo-nal design L16 (4(5)). A suitable SCoT-PCR system for D. glomerata was established; the 20 µL reaction volume contained 3.0 mM Mg(2+), 0.2 mM dNTPs, 1.0 U Taq DNA polymerase, 0.2 µM primer, 20 ng tem-plate DNA, and 2 µL 10X buffer. Each factor had a different effect on the amplification reaction, and the concentration of dNTPs had the larg-est effect on the SCoT-PCR system. We tested 10 orchardgrass samples to determine and verify the stability of the reaction system. The results showed that amplified bands from diverse materials were clear, stable, and rich in polymorphisms, indicating that the optimized system was very stable.
Assuntos
Códon de Iniciação , Dactylis/genética , Reação em Cadeia da Polimerase/métodos , Primers do DNA , DNA de Plantas/análise , DNA de Plantas/genéticaRESUMO
Cynodon dactylon (L.) Pers. var. dactylon (common bermudagrass) is widely distributed geographically between approximately 45°N and 45°S latitude, penetrating to approximately 53°N latitude in Europe. The extensive variation of morphological and adaptive characteristics of the taxon has been substantially documented, but information is lacking on DNA molecular variation in geographically disparate forms. The genetic diversity of 51 wild accessions of bermudagrass from southwest China (Sichuan, Chongqing, Yunnan, Guizhou, and Tibet) and 8 African bermudagrass was analyzed using amplified fragment length polymorphism molecular markers. A total of 670 polymorphic bands were detected with 11 primer combinations, of which 663 (98.74%) bands were found to be polymorphic. The genetic similarity among the accessions ranged from 0.64-0.96 with an average of 0.78. All 59 wild accessions were clustered into 5 eco-geographic groups, and nearly all accessions from the same area were classified into the same group and were found to be associated with their geographical distributions. Therefore, complex geographical and ecological environments are important factors for the genetic structure and geographical distribution of C. dactylon.
Assuntos
Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Cynodon/genética , Marcadores Genéticos , Variação Genética , África , China , Análise por Conglomerados , Cynodon/classificação , Primers do DNA , DNA de Plantas/genética , Filogenia , Filogeografia , Análise de Componente PrincipalRESUMO
Sequence-related amplified polymorphism (SRAP) markers were used to analyze and estimate the genetic variability, level of diversity, and relationships among 20 cultivars and strains of annual ryegrass (Lolium multiflorum Lam.). Eighteen SRAP primer combinations generated 334 amplification bands, of which 298 were polymorphic. The polymorphism information content ranged from 0.4715 (me10 + em1) to 0.5000 (me5 + em7), with an average of 0.4921. The genetic similarity coefficient ranged from 0.4304 to 0.8529, and coefficients between 0.65 and 0.90 accounted for 90.00%. The cluster analysis separated the accessions into five groups partly according to their germplasm resource origins.
Assuntos
Lolium/genética , Polimorfismo Genético , Análise por Conglomerados , Marcadores Genéticos , Genoma de Planta , Lolium/classificação , Filogenia , Folhas de Planta/genéticaRESUMO
Chicory is a crop with economically important roles and is cultivated worldwide. The genetic diversity and relationship of 80 accessions of chicories and endives were evaluated by sequence-related amplified polymorphism (SRAP) markers to provide a theoretical basis for future breeding programs in China. The polymorphic rate was 96.83%, and the average polymorphic information content was 0.323, suggesting the rich genetic diversity of chicory. The genetic diversity degree of chicory was higher (GS = 0.677) than that of endive (GS = 0.701). The accessions with the highest genetic diversity (effective number of alleles, NE = 1.609; Nei's genetic diversity, H = 0.372; Shannon information index, I = 0.556) were from Italy. The richest genetic diversity was revealed in a chicory line (NE = 1.478, H = 0.289, I = 0.443) among the 3 types (line, wild, and cultivar). The chicory genetic structure of 8 geographical groups showed that the genetic differentiation coefficient (GST) was 14.20% and the number of immigrants per generation (Nm) was 3.020. A GST of 6.80% and an Nm of 6.853 were obtained from different types. This observation suggests that these chicory lines, especially those from the Mediterranean region, have potential for providing rich genetic resources for further breeding programs, that the chicory genetic structure among different countries obviously differs with a certain amount of gene flow, and that SRAP markers could be applied to analyze genetic relationships and classifications of Cichorium intybus and C. endivia.
Assuntos
Cichorium intybus/genética , Genes de Plantas , Marcadores Genéticos , Polimorfismo Genético , Família Multigênica , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Orchardgrass, or cocksfoot, is an important perennial forage grass worldwide. The comprehensive understanding of orchardgrass accessions will benefit germplasm collection and breeding progress, and it will enhance efforts to improve forage yield and quality. Therefore, 24 novel, simple, polymorphic, and reliable start codon-targeted (SCoT) markers were used to analyze the diversity and genetic relationships among 95 orchardgrass accessions. In total, 273 polymorphic bands were detected with an average of 11.4 bands per primer. The average polymorphic rate for the species was 83.4%, suggesting a high discriminating ability of the SCoT technique for orchardgrass. The molecular variance analysis revealed that 69.13 and 30.87% of variation resided within and among groups, respectively, demonstrating that the orchardgrass germplasms had a higher level of genetic diversity within groups than among geographical regions and distributions. The distinct geographical divergence of orchardgrass was revealed between North America and Oceania. The unweighted pair-group method with arithmetic mean dendrogram revealed a separation of 7 main clusters between 95 accessions according to the geographical origin. Furthermore, each cluster was divided into subgroups mainly according to the origin of its state. The genetic divergence of orchardgrass might be influenced by the ecogeographical conditions, climatic types, breeding systems and gene flow with variations in cultures, bird migration, and breeder selection. These results could facilitate orchardgrass germplasm collection, management, and breeding worldwide.
Assuntos
Códon de Iniciação , Dactylis/classificação , Dactylis/genética , Variação Genética , Evolução Molecular , Marcadores Genéticos , Genoma de Planta , Filogeografia , Polimorfismo GenéticoRESUMO
Six F1 populations derived from crosses among 4 orchardgrass (Dactylis glomerata L.) cultivars were studied by morphological and simple sequence repeat molecular markers to test for hybrid vigor and a correlation between genetic distance and heterosis. Heterosis was observed for days to length of culm, leaf traits, tiller numbers, etc. Significant differences between obverse and inverse crosses were found for eleven traits. A cytoplasmic effect existed for the agronomic traits considered in this study. The correlations between genetic distance and heterosis were investigated by analyzing the performance of 3 crosses. The results showed that genetic distance was significantly correlated with tiller number (r = 0.834) and negatively correlated with length of culm (r = -0.889). However, there was no significant correlation with heterosis for the other traits, including yield; the correlation coefficient were too small to allow prediction of orchardgrass heterosis from the parental genetics.
Assuntos
Dactylis/genética , Vigor Híbrido/genética , Hibridização Genética , Cruzamentos Genéticos , Dactylis/crescimento & desenvolvimento , Repetições de Microssatélites/genética , FenótipoRESUMO
The accurate identification of orchardgrass (Dactylis glomerata L.) cultivars is necessary to ensure purity for consumers, the effective utilization of cultivars, and to protect the intellectual property for breeders. Therefore, this study aimed to use SSR to construct DNA fingerprinting of orchardgrass cultivars. The genetic diversity of 32 orchardgrass cultivars originated from 21 countries, but grown in China, was assessed using a set of 29 SSR markers distributed across 9 linkage groups of the orchardgrass genome. A total of 229 bands were detected, with an average of 7.9 bands per marker. The average polymorphic rate for the species was 92.1%. The polymorphism information content ranged from 0.771 to 0.893. The genetic similarity ranged from 0.55 to 0.84, which confirmed a high level of genetic diversity among orchardgrass cultivars. The unweighted pair-group method, in combination with the arithmetic mean algorithm (UPGMA) dendrogram and principal coordinate analysis, showed a separation of 6 major clusters among 32 cultivars. The number of distinguishable cultivars ranged from 3 to 23, with an average of 12.1 per primer. Moreover, 11 bands that showed stable and repeatable SSR patterns were amplified by A01E14, A01K14, and D02K13. These bands were used to develop the DNA fingerprints for 32 orchardgrass cultivars. In the DNA fingerprints constructed, each cultivar had a unique fingerprinting pattern that was easily distinguished from the others. These results indicate that the SSR marker was polymorphic, and reliable for use in potential large-scale DNA fingerprinting of orchardgrass cultivars.
Assuntos
Dactylis/classificação , Dactylis/genética , Repetições de Microssatélites , Impressões Digitais de DNA , Ligação Genética , Variação Genética , Filogenia , Polimorfismo GenéticoRESUMO
Agropyron Gaertn. is the most important genus in Triticeae (Poaceae), which includes many forage grasses with high economic value. The genetic diversity and relationships of 36 accessions from five crested wheatgrass species were analyzed by gliadin markers. A total of 54 product bands were detected after acid polyacrylamide gel electrophoresis (A-PAGE), of which 100% were polymorphic. The genetic similarity coefficient based on Nei-Li's method ranged from 0.065 to 0.755 with an average of 0.451. The Shannon diversity information index showed that there was a high level of genetic diversity among the accessions. An unweighted pair group method with arithmetic average (UPGMA) dendrogram was constructed based on the Nei-Li's genetic similarity coefficients, which showed the phylogenetic relationships among accessions of different species. Analysis of molecular variance (AMOVA) showed that the proportion of variance explained by inter- and intraspecific variance was 9.34 and 90.66%, respectively, which revealed that the genetic variations within species were higher than the variations among species. Based on pairwise genetic distances (ΦST) among species, the cluster analysis indicated that A. mongolicum had a low-affinity relationship with other species, while A. fragile showed a close relationship with A. cristatum ssp pectinatum. Finally, the implications of the results for the taxonomy of Agropyron were discussed.
Assuntos
Agropyron/genética , Variação Genética , Gliadina/genética , Agropyron/classificação , FilogeniaRESUMO
The genus Lolium is one of the most important groupings of temperate forage grasses, including about eight recognized species that are native to some temperate and subtropical regions of the northern hemisphere. We examined genetic relationships among 18 accessions representing all Lolium species using RAPD markers. Among 50 random primers that we screened, 13 gave reproducible amplification banding patterns. Each of these 13 primers generated 19-43 scorable fragments. A total of 367 RAPD fragments were detected, of which 95.9% were polymorphic across all the Lolium accessions. Dice's coefficient of dissimilarity ranged from 0.016 to 0.622, which is indicative of substantial genetic variations in these Lolium accessions. A neighbor-joining cluster analysis, with bootstrap permutation, produced an unrooted dendrogram, which grouped 18 accessions into two main clades, supporting high bootstrap values (98 and 96%). The first clade included the self-pollinated species, L. persicum, L. temulentum, L. remotum, and L. subulatum. The cross-pollinated species, i.e., L. multiflorum, L. perenne, L. rigidum, and L. canariense, composed the second clade, in which L. canariense formed a distinct subclade, indicating its higher genetic separation from other allogamous species. The value of r = 0.97 in the Mantel test for cophenetic correlation applied to the cluster analysis indicated the high degree of fit of the accessions to a group. A principal coordinate analysis, whose first three coordinates explained 72.6% of the variation, showed similar groupings as in the cluster analysis. The genetic relationships estimated by the polymorphism of RAPD markers are basically in agreement with those previously inferred with other genetic markers.
Assuntos
Marcadores Genéticos , Lolium/genética , Filogenia , Técnica de Amplificação ao Acaso de DNA Polimórfico , DNA de Plantas , Polimorfismo Genético , Análise de Componente PrincipalRESUMO
Hemarthria compressa is one of the most important and widely utilized forage crops in south China, owing to its high forage yield and capability of adaptation to hot and humid conditions. We examined the population structure and genetic variation within and among 12 populations of H. compressa in south China using sequence-related amplified polymorphism (SRAP) markers. High genetic diversity was found in these samples [percentage polymorphic bands (PPB) = 82.21%, Shannon's diversity index (I) = 0.352]. However, there was relatively low level of genetic diversity at the population level (PPB = 29.17%, I = 0.155). A high degree of genetic differentiation among populations was detected based on other measures and molecular markers (Nei's genetic diversity analysis: G(ST) = 54.19%; AMOVA analysis: F(ST) = 53.35%). The SRAP markers were found to be more efficient than ISSR markers for evaluating population diversity. Based on these findings, we propose changes in sampling strategies for appraising and utilizing the genetic resources of this species.
Assuntos
Variação Genética , Poaceae/genética , Polimorfismo Genético , Sequência de Bases , China , Análise por Conglomerados , Marcadores Genéticos , Genética Populacional , Geografia , FilogeniaRESUMO
Orchardgrass is a highly variable, perennial forage grass that is cultivated throughout temperate and subtropical regions of the world. Despite its economic importance, the genetic relationship and distance among and within cultivars are largely unknown but would be of great interest for breeding programs. We investigated the molecular variation and structure of cultivar populations, compared the level of genetic diversity among cultivars (Baoxing, Anba, Bote, and Kaimo), subspecies (Dactylis glomerata ssp Woronowii) and advanced breeding line (YA02-116) to determine whether there is still sufficient genetic diversity within presently used cultivars for future breeding progress in China. Twenty individuals were analyzed from each of six accessions using SSR markers; 114 easily scored bands were generated from 15 SSR primer pairs, with an average of 7.6 alleles per locus. The polymorphic rate was 100% among the 120 individuals, reflecting a high degree of genetic diversity. Among the six accessions, the highest genetic diversity was observed in Kaimo (H = 0.2518; I = 0.3916; P = 87.3%) and 02-116 had a lower level of genetic diversity (H = 0.1806; I = 0.2788; P = 58.73%) compared with other cultivars tested. An of molecular variance revealed a much larger genetic variation within accessions (65%) than between them (35%). This observation suggests that these cultivars have potential for providing rich genetic resource for further breeding program. Furthermore, the study also indicated that Chinese orchardgrass breeding has involved strong selection for adaptation to forage production, which may result in restricted genetic base of orchardgrass cultivar.