Maize (Zea mays L.) and Asian rice (Oryza sativa L.), two most important cereals for human nutrition, have undergone strong artificial selection during a long period of time. Currently, a number of genes with stronger signals of selection have been identified through combining genomic and population genetic approach, but research on artificial selection of maize and Asian rice is scarcely done from the perspective of phenotypic difference of a number of agronomic traits. In this study, such an investigation was carried out on the basis of 179 published studies about phenotypic quantitative trait locus (QTL) mapping of Zea and Oryza species via QTL sign test. At the overall level, the proportions of antagonistic QTLs of Zea and Oryza species were 0.2446 and 0.2382 respectively, deviating significantly from neutrality. It indicated that these two genera have undergone similar selection strength during their evolutionary process. A previous study showed that 4 traits undergoing the directional selection during domestication were identified in Asian rice via QTL sign test, and 16 individual traits in Asian rice and 38 ones in maize that newly detected in this study deviated significantly from neutrality as well, demonstrating the dominant influence of artificial selection on them. Moreover, analysis of different categories of cross type including O. sativa × Oryza rufipogon (perennial and annual forms) crosses, maize × teosinte (Zea mays subsp. parviglumis) crosses, O. sativa × O. sativa crosses, and maize × maize crosses showed that their proportions of antagonistic QTLs were 0.1869, 0.1467, 0.2649, and 0.2618 respectively. These results revealed that selection strength of domestication is significantly stronger than that of modern genetic improvement. However, interestingly, the proportion of antagonistic QTLs (0.1591) in maize × maize with long-term selection was very similar to that (0.1467) in the maize × teosinte (Zea mays subsp. parviglumis) crosses. It suggested that some favorable traits could be cultivated within a few decades if we carry out strong selection. In addition, the proportions of antagonistic QTLs of the widely cultivated hybrids of rice (Minghui 63 × Zhenshan 97) and maize (Zheng 58 × Chang 7-2) in China were 0.309 and 0.3472 respectively. It suggested that selection during modern genetic improvement has significantly acted on them. 相似文献
Analysis of the genetic structure of Indonesian Oryza sativa and O. rufipogon using neighbour-joining trees based on single nucleotide polymorphism (SNP) and simple sequence repeat (SSR) markers revealed that O. sativa in Indonesia is separated from O. rufipogon. Accessions of O. sativa in this study were differentiated into two major groups, indica and tropical japonica, excluding some varieties. SSR and SNP markers revealed the high value of differentiation (FST) and genetic distance (D) between indica and tropical japonica and we discovered four loci by SNP markers and one locus by SSR markers that play a role in differentiation between indica and tropical japonica. Interestingly, genetic diversity (H) in O. rufipogon was lower than that in O. sativa, however H in O. rufipogon was the highest and H in tropical japonica was the lowest when O. sativa was divided into two groups. Inbreeding coefficient (Fst) showed evidences that gene flow (Nm) between species and within species might be one of the mechanisms related to the diversification and differentiation of Indonesian rice germplasm by asymmetric pattern between species and within O. sativa as revealed by SSR and SNP markers. In addition, we found evidences on stabilizing selection in Indonesian rice germplasm and they might be the reasons why Indonesian rice germplasm did not differentiate due to source location of landrace. However, we found a weak relation between SSR and SNP markers probably due to highly polymorphic in SSR and the different properties of both markers. 相似文献
Asian rice (Oryza sativa L.) is widely cultivated in Asia, where it has been classified into Indica and Japonica Group, the latter is further classified into Tropical and Temperate Japonica Subgroup. O. rufipogon is believed to be the closest ancestor to O. sativa, but it remains unclear whether the two groups arose from a single ancestor or different ancestors. Therefore, here, we investigated the matrilineal ancestors of O. sativa using markers for organelle (chloroplast and mitochondrial) genomes, and 119 O. sativa landraces, 10 O. glaberrima Steud., 115 O. rufipogon Griff. from Asia, and 39 accessions from other wild rice species with AA genomes. We screened 18 organelle markers developed based on polymorphic loci in the organelle genomes. In addition, we used the open reading frame 100 of a chloroplast marker. The results indicated that O. rufipogon first differentiated into two lineages and then further differentiated into Indica and Japonica Group, respectively. Accessions of O. rufipogon (R-1f and R-2d types) from Myanmar appear to be the closest ancestors of Tropical Japonica Subgroup and Indica Group, respectively. Therefore, these wild strains may have made a strong contribution to the domestication of rice landraces in Myanmar. 相似文献
Low molecular weight carbohydrates of seeds of 10 species of Vicia, namely: V. angustifolia, V. articulata, V. cordata, V. ervilia, V. johannis, V. macrocarpa, V. monantha, V. narbonensis, V. pannonica and V. sativa were analyzed by the high resolution gas chromatography method. Seeds of the investigated species contain common (glucose, fructose, myo-inositol, sucrose, galactinol, di-galactosyl myo-inositol and raffinose family oligosaccharides—RFOs) and species-specific carbohydrates (d-pinitol and its α-d-galactosides—in V. articulata, V. monantha and V. pannonica or d-ononitol and its galactoside—in V. ervilia). Among the species containing in seeds RFOs as the main α-d-galactosides (V. angustifolia, V. cordata, V. johanensis, V. macrocarpa, V. narbonensis and V. sativa), an additional subgroup can be separated, which contains a set of unknown compounds (found in V. angustifolia, V. cordata and V. macrocarpa). Moreover, several other unidentified carbohydrate-containing compounds were detected exclusively in seeds of V. ervilia. The concentrations of total soluble carbohydrates (TSCs), including sugars, RFOs, cyclitols and galactosyl cyclitols and unknown compounds, in seeds differ significantly (P < 0.05) among the species. RFOs and sucrose are the main fractions in TSCs, with the exception of V. pannonica seeds, containing more galactosyl pinitols, and V. ervilia, in which unknown compounds account for 50% of TSCs. In V. ervilia RFOs occur at the lowest concentration (9.32 mg g?1 seeds), and the concentration of DGMI (di-galactosyl myo-inositol) is comparable with that of RFOs, which is unusual among all the investigated Vicia species. 相似文献
Microbial food webs tolerate toxic compounds depending on individualistic species resistance and their ability of using alternate food sources. Soil polluted with low-molecular weight volatile organics, such as hexane, diminishes bacterial and fungal communities despite its short residence time. Survival of microbial species depends on perturbation intensity, which in turn restricts resources for amoebae survival in polluted soil. Soil functional recovery from anthropogenic perturbations depends on microbial organic matter (OM) metabolization of pollutants. However, reconfiguration of amoebae community after soil exposure remains largely unknown. A microcosms study was carried out to determine the effects of hexane on the community structure of soil amoebae as well as the importance of Medicago sativa on amoebae community recovering. Hexane had a negative impact on species richness and structure of the amoebae community 24 h after pollution. There was a significant increase in species richness and number of amoebae 30 days after contamination. These two parameters further increased after 60 days from contamination. After 30 days of the initial trophozoites extinction caused by Hexane, M. sativa’s. Root zone showed a significant increase of both species richness and number of individuals. This recovery trend was kept after 60 days when the highest values in species richness and abundance of individuals were shown in both polluted and non-polluted microcosms. In conclusion, M. sativa’s root zone speeds up recovery of the amoebae community structure after pollution exposure. 相似文献
Developing a molecular tool kit for hybrid breeding of Osmanthus species and related genera is an important step in creating a systematic breeding program for this species. To date, molecular resources have been aimed solely at Osmanthus fragrans with little work to develop markers for other species and cultivars. The objectives of this study were to (1) determine cross-transferability of O. fragrans and Chionanthus retusus derived SSRs in diverse Osmanthus taxa, (2) quantify the influence of locus-specific factors on cross-transferability, and (3) determine the genetic relationships between accessions. We tested 70 SSR markers derived from O. fragrans and C. retusus in 24 accessions of Osmanthus. Sixty-seven markers showed transfer to at least one other Osmanthus species with an overall transfer rate of 84% of loci across taxa. Genotyping with 42 microsatellite markers yielded a total of 367 loci. Number of alleles per locus ranged from 2 to 17 with a mean of 8.7 ± 4.8. Mean observed and expected heterozygosities were 0.560 ± 0.225 and 0.688 ± 0.230, respectively. Percent of polymorphic loci ranged from 40% in Osmanthus delavayi to 100% in O. fragrans. Osmanthus fragrans had the highest mean number of alleles per locus (4.2) while O. delavayi had the lowest (1.1). A reduced suite of eight-markers can distinguish between accessions with non-exclusion probabilities of identity from 3.91E?04 to 2.90E?07. The SSR markers described herein will be immediately useful to characterize germplasm, identify hybrids, and aid in understanding the level of genetic diversity and relationships within the cultivated germplasm. 相似文献
Lettuce (Lactuca sativa L.) belongs to the genus Lactuca L. and is an important vegetable worldwide. Over the past decades, there have been many controversies about the phylogeny of Lactuca species due to their complex and diverse morphological characters and insufficient molecular sampling. In this study we provide the most extensive molecular phylogenetic reconstruction of Lactuca, including African wild species, using two chloroplast genes (ndhF and trnL-F). The sampling covers nearly 40 % of the total endemic African Lactuca species and 34 % of the total Lactuca species. DNA sequences from all the subfamilies of Asteraceae in Genebank and those generated from Lactuca herbarium samples were used to establish the affiliation of Lactuca within Asteracaeae. Based on the subfamily tree, we selected 33 ndhF sequences from 30 species and 79 trnL-F sequences from 48 species to infer relationships within the genus Lactuca using randomized axelerated maximum likelihood and Bayesian inference analyses. Biogeographical, chromosomal and morphological character states were reconstructed over the Bayesian tree topology. We conclude that Lactuca contains two distinct phylogenetic clades—the crop clade and the Pterocypsela clade. Other North American, Asian and widespread species either form smaller clades or mix with the Melanoseris species. The newly sampled African endemic species probably should be treated as a new genus. 相似文献
Plants of the Pilocarpus genus (Rutaceae) are popularly known as jaborandi and are the only source of pilocarpine, an imidazole alkaloid used in eye-drops for the treatment of glaucoma as well as for the stimulation of sweat and lachrymal glands. Alkaloid extracts from leaf samples of seven species of Pilocarpus, from the states of São Paulo and Maranhão in Brazil, were analyzed using HPLC–ESI–MS/MS. The samples contained between 0.88 ± 0.04 and 1.00 ± 0.14% of alkaloids in relation to the dry weight of their leaves, with significant differences in results (P ≤ 0.05) found only between Pilocarpus microphyllus planted in the state of Maranhão and Pilocarpus spicatus, Pilocarpus trachyllophus, Pilocarpus pennatifolius and Pilocarpus jaborandi; as well as between Pilocarpus spicatus and Pilocarpus racemosus. Pilocarpine was not found in P. spicatus, whereas in the other species it ranged from 2.6 ± 0.1 to 70.8 ± 1.2% of total alkaloids. P. microphyllus planted in the state of Maranhão for pilocarpine extraction had the highest total alkaloid content, but it had only 35% of pilocarpine in relation to total alkaloids. Three other species contained more pilocarpine in relation to total alkaloids: P. jaborandi (70.8%), P. racemosus (45.6%) and P. trachyllophus (38.7%); and could be candidates for pilocarpine extraction. Differences in alkaloid content were significant for all these samples (P ≤ 0.05). Imidazole alkaloids were observed and partially characterized based on their retention times and high resolution mass. The seven species analyzed had different imidazole alkaloid profiles, but only one did not present quantifiable pilocarpine contents in its leaves. The Pilocarpus genus shows potential for the prospection of novel alkaloids. 相似文献
A hybrid between Erianthus arundinaceus (Retz.) Jeswiet and Saccharum spontaneum L. which are wild related species of sugarcane (Saccharum L., Family Poaceae), was repeatedly crossed as female parent with sugarcane commercial varieties to develop near commercial sugarcane clones. The cytoplasm type of the hybrid derivatives were confirmed to be of E. arundinaceus through the mitochondrial and chloroplast DNA polymorphism of nad 4/3-4 intron segment and psbC–trnS segment, respectively. The E. arundinaceus × S. spontaneum hybrid with somatic chromosome number 2n = 62 was confirmed to have 30 chromosomes from E. arundinaceus through genomic in situ hybridization (GISH). The (E. arundinaceus × S. spontaneum) × sugarcane hybrid (2n = 118) had 24 chromosomes from E. arundinaceus whereas its next generation hybrid with sugarcane (2n = 108) had only 12 Erianthus chromosomes. The commercial sugarcane hybrid Co 15015, which is the third generation hybrid with 2n = 106 was confirmed to have two E. arundinaceus chromosomes through GISH. It is the first report of sugarcane with both alien cytoplasm and chromosome contributions from E. arundinaceus. 相似文献
Aloe species, which have been used as medicinal plants, belong to the Asphodelaceae family consisting of 530 species. In this study, genetic diversity and phylogenetic relationships among 40 Aloe species including a putative interspecies hybrid were analyzed using PCR band profiles from eight chloroplast intergenic space markers and nucleotide sequence diversity in the psbK–psbI intergenic region. A phylogenetic tree based on psbK–psbI sequences supported the revised classification of the genus Aloe as polyphyletic with several species be re-allocated into three genera Kumara, Aloidendron, and Aloiampelos. Further, the origin of the putative interspecies Aloe hybrid was characterized through molecular cytogenetics. Fluorescence and genomic insitu hybridization illustrated that the hybrid has a bimodal karyotype with a chromosome complement of 2n = 14, of which complementary halves were derived from two parental species, A. vera and A. arborescens. These findings revealed that the hybrid species was allodiploid. The phylogenetic analysis showed that A. arborescens was the maternal genome donor of the hybrid, as both have identical chloroplast genome sequences. We thus conclude that the allodiploid hybrid should be called A. arborescens × A.vera.相似文献
Three wild carrot species have been reported in the argentinian flora: Daucus montanus Humb. et Bonpl. ex Schult., D. montevidensis Link ex Sprengel and D. pusillus Michx. There is a discrepancy among authors about the distinctive morphological traits of the last two species; thus, it is difficult to ascertain if they are truly two distinct taxa. Based on the available literature and in the search of a paradigmatic site, four collection trips were carried out in 2004 and 2005 in Buenos Aires and Southern Entre Ríos provinces. Populations were sampled at 30 sites, and local environmental parameters and associated plant species were recorded. Morphological observations and chromosome counts were carried out on 10 plants/population. Three morphological phenotypes were distinguished: one in 18 populations, all with 2n = 2x = 18, and two in the remaining 12, with 2n = 2x = 22 or aneusomaty (2n = 2x = 20, 22). Populations of the first phenotype were assigned to wild D. carota and the rest, tentatively, to D. pusillus (D. montevidensis?), till further evaluations are carried out in test sites to verify this tentative conclusion. 相似文献
Ecosystem restorations can impact carbon dioxide (CO2) and nitrous oxide (N2O) emissions which are important greenhouse gasses. Alpine meadows are degraded worldwide, but restorations are increasing. Because their soils represent large carbon (C) and nitrogen (N) pools, they may produce significant amounts of CO2 and N2O depending on the plant species used in restorations. In addition, warming and N deposition may impact soil CO2 and N2O emissions from restored meadows.
Materials and methods
We collected soils from degraded meadows and plots restored using three different plant species at Wugong Mountain (Jiangxi, China). We measured CO2 and N2O emissions when soils were incubated at different temperatures (15, 25 or 35 °C) and levels of N addition (control vs. 4 g m?2) to understand their responses to warming and N deposition.
Results and discussion
Dissolved organic C was higher in restored plots (especially with Fimbristylis dichotoma) compared to non-restored bare soils, and their soil inorganic N was lower. CO2 emission rates were increased by vegetation restorations, decreased by N deposition, and increased by warming. CO2 emission rates were similar for the three grass species at 15 and 25 °C, but they were lower with Miscanthus floridulus at 35 °C. Soils from F. dichotoma and Carex chinensis plots had higher N2O emissions than degraded or M. floridulus plots, especially at 25 °C.
Conclusions
These results show that the effects of restorations on soil greenhouse gas emissions depended on plant species. In addition, these differences varied with temperature suggesting that future climate should be considered when choosing plant species in restorations to predict soil CO2 and N2O emissions and global warming potential.
Since the development of effective N2O mitigation options is a key challenge for future agricultural practice, we studied the interactive effect of tillage systems on fertilizer-derived N2O emissions and the abundance of microbial communities involved in N2O production and reduction. Soil samples from 0–10 cm and 10–20 cm depth of reduced tillage and ploughed plots were incubated with dairy slurry (SL) and manure compost (MC) in comparison with calcium ammonium nitrate (CAN) and an unfertilized control (ZERO) for 42 days. N2O and CO2 fluxes, ammonium, nitrate, dissolved organic C, and functional gene abundances (16S rRNA gene, nirK, nirS, nosZ, bacterial and archaeal amoA) were regularly monitored. Averaged across all soil samples, N2O emissions decreased in the order CAN and SL (CAN?=?748.8?±?206.3, SL?=?489.4?±?107.2 μg kg?1) followed by MC (284.2?±?67.3 μg kg?1) and ZERO (29.1?±?5.9 μg kg?1). Highest cumulative N2O emissions were found in 10–20 cm of the reduced tilled soil in CAN and SL. N2O fluxes were assigned to ammonium as source in CAN and SL and correlated positively to bacterial amoA abundances. Additionally, nosZ abundances correlated negatively to N2O fluxes in the organic fertilizer treatments. Soils showed a gradient in soil organic C, 16S rRNA, nirK, and nosZ with greater amounts in the 0–10 than 10–20 cm layer. Abundances of bacterial and archaeal amoA were higher in reduced tilled soil compared to ploughed soils. The study highlights that tillage system induced biophysicochemical stratification impacts net N2O emissions within the soil profile according to N and C species added during fertilization. 相似文献
In this study, ecological, morphological and genetic diversity in 11 surviving populations of Oryza rufipogon Griff. from Hainan Island, China were investigated. These data served to provide much needed data in support of conservation strategies. The results divided O. rufipogon into six ecotypes. The cluster analysis based on 19 morphological features showed clear differentiation among populations or within populations. The cluster analysis based on SSR also revealed similar results. The ecological, morphological and genetic diversity observed in O. rufipogon resulted in the following conservation recommendations: (1) the four currently protected O. rufipogon localities should be maintained, due to the different ecological communities represented at these sites; (2) some populations, such as HL (Hele county, Hainan Island), should be protected, but some populations, such as FC (Fucheng county, Hainan Island) and DL (Dalu county, Hainan Island), might not be protected. (3) An isolation zone should be established to avoid possible introgression between O. sativa L. and O. rufipogon; and human activities that impact O. rufipogon should be reduced or eliminated. 相似文献
This study evaluated the effect of silicate fertilizer on denitrification and associated gene abundance in a paddy soil. A consecutive trial from 2013 to 2015 was conducted including the following treatments: control (CK), mineral fertilizer (NPK), NPK plus sodium metasilicate (NPK + MSF), and NPK plus slag-based silicate fertilizer (NPK + SSF). Real-time quantitative PCR (qPCR) was used to analyze the abundances of nirS, nirK, and nosZ genes. Potential N2O emissions and ammonium and nitrate concentrations were related to the nirS and nirK gene abundance. Compared with the NPK treatments, the addition of a Si fertilizer decreased N2O emission rates and denitrification potential by 32.4–66.6 and 22.0–59.2%, respectively, which were probably related to increased rice productivity, soil Fe availability, and soil N depletion. The abundances of nirS and nirK genes were decreased by 17.7–35.8% and 21.1–43.5% with addition of silicate fertilizers, respectively. Rates of total N2O and N2O from denitrification (DeN2O) emission were positively correlated with the nirS and nirK gene abundance. Nitrate, exchangeable NH4+, and Fe concentrations were the main factors regulating the nirS and nirK gene abundance. Silicate fertilization during rice growth may serve as an effective approach to decreasing N2O emissions. 相似文献
Vitellaria paradoxa C. F. Gaertn., commonly known as shea tree or Vitellaria, is ranked the most important tree species of the savannah regions in the most African countries due to its ecological and economic importance for livelihoods and national economies. However, the savannah regions are the most vulnerable areas to the global climate change. Moreover, the Vitellaria populations on farmlands are threatened by the dominance of old trees with low or lack of regeneration. In this study both morphological and genetic diversity were assessed using several phenotypic traits and 10 microsatellite markers, respectively, to assess the impact of land use and agro-ecozone types on Vitellaria in Ghana. The land use types were forests and farmlands, and the agro-ecozone types included the Transitional, Guinea, and Sudan savannah zones. The mean values of morphological traits, such as diameter at breast height (DBH) and canopy diameter (CD), were statistically different between forest (DBH = 22.20, CD = 5.37) and farmland (DBH = 39.85 CD = 7.49) populations (P < 0.00001). The Sudan savannah zone with mean petiole length of 4.96 cm showed significant difference from the other zones, likely as a result of adaptation to drier climate conditions. Genetic data analysis was based on 10 microsatellite markers and revealed high genetic diversity of Vitellaria in Ghana: mean expected heterozygosity, He was 0.667, and allelic richness, measured as number of effective alleles Ae, was 4.066. Both farmlands and forests were very diverse indicating lack of negative influence of farmer’s selection on genetic diversity. Fixation index was positive for all populations (mean FIS = 0.136) with farmlands recording relatively higher values than forests in all ecological zone types studied, probably indicating less gene flow in the farmlands. Moderate differentiation (F′ST = 0.113) was comparable to other similar tree species. Both land use and ecological zone types influenced genetic differentiation of Vitellaria at varying levels. The species was spatially structured across three ecozones and following climatic gradient. The forest reserves are used in situ conservation for Vitellaria in Ghana. High diversity observed in the most arid zones provides opportunity to find and use appropriate plant materials for breeding climate change resilient trees. 相似文献
Because crop uptake of arsenic from soils poses a human health concern, this study examines the effect of plant species, neighborhood, and planting density on arsenic uptake by brassicas grown with companion crops. At a field site contaminated by arsenic and lead, we measured arsenic uptake in arugula (Eruca sativa) and collards (Brassica oleracea var. acephala) grown in arrangements varying in species diversity and density. We further tested the effect of species diversity on arsenic uptake in two greenhouse experiments with arsenic-spiked potting soil, one test using brassicaceous plants with intercropped pairs of arugula, collards, and kale (B. oleracea var. acephala). The other had intercropped pairs of arugula, lettuce (Lactuca sativa), and marigold (Tagetes patula). Arugula in all cropping arrangements accumulated the highest and most variable concentrations of arsenic compared to other species, with neither species diversity in the companion crops nor planting density affecting arsenic uptake. We observed increased phosphorus and sulfur uptake by arugula exposed to soil arsenic in the greenhouse brassica intercropping experiments, a result that may be explained by a biological response to arsenic or competition of arsenate with phosphate and sulfate for adsorption sites in the soil. Arsenic uptake was largely independent of plant-plant facilitation effects sometimes reported for other elements, possibly because of strong buffering of the bioavailable fraction of arsenic in the soils tested. 相似文献
Although dilution of lake water has been used for improvement of water quality and algal blooms control, it has not necessarily succeeded to suppress the blooms. We hypothesized that the disappearance of algal blooms by dilution could be explained by flow regime, nutrient concentrations, and their interaction. This study investigated the effects of daily renewal rate (d), nitrogen (N) and phosphorus (P) concentration, and their interaction on the domination between Microcystis aeruginosa and Cyclotella sp. through a monoxenic culture experiment. The simulation model as functions of the N:P mass ratio and dilution rate (D) (calculated from d) was constructed, and the dominant characteristics of both species were predicted based on the model using parameters obtained in a monoculture experiment and our previous study. Results of monoxenic culture experiment revealed that M. aeruginosa dominated in all conditions (d = 5 or 15%; N = 1.0 or 2.5 or 5.0 mg-N L?1; P = 0.1 or 0.5 mg-P L?1) and the predicted cell densities were substantially correspondent to experimental data. Under various N:P ratios and D values, characteristics of domination for each species were predicted, indicating that Cyclotella sp. tended to be dominant under high P concentrations (P ≥ 0.36 mg-P L?1) when the N:P ratio was less than 7.0, and M. aeruginosa could not form algal blooms at the N:P ratio ≤ 7.0 (N ≤ 0.7 mg-N L?1). It was also suggested that the dilution rate leading to the Cyclotella sp. domination required 0.20 day?1 or higher regardless of the N:P ratios.
Graphical Abstract? M. aeruginosa and Cyclotella sp. could be a superior competitor in nutrient-limited and nutrient-rich conditions, respectively. ? The simulation model in this study indicated that the predicted cell density and nutrient concentration were substantially correspondent to experimental data. ? The model predicted that Cyclotella sp. tended to be dominant at the P ≥ 0.36 mg-P L?1 when the N:P ratio was less than 7.0, and M. aeruginosa could not form algal blooms at the N:P ratio ≤ 7.0 (N ≤ 0.7 mg-N L?1).
Significant genetic diversity was observed in 218 out of a total of 1309 accessions of amaranth (Amaranthus hypochondriacus L.) and its seven wild relatives, A. spinosus L., A. dubius Mart. ex Thell., A. hybridus L., A. tricolor L., A. cruentus L., A. caudatus L., A. retroflexus L. for 24 nutritional parameters including total oil content, fatty acid profile, total protein content and amino acid profile. Diversity for total oil content (6.42–12.53%), linoleic acid (25.68–54.34%), oleic acid (21.97–42.01%) of the total fatty acids, total protein content (7.84–18.01%), among important essential amino acids; lysine content (0.66–11.12 g/16 g N), methionine (0.35–4.80 g/16 g N) and half cystine and (0.12–8.32 g/16 g N) was reported. The un-weighted pair-group method using arithmetic average cluster analysis based on pair wise Euclidean genetic distance grouped the accessions into seven major clusters. Histidine, half cystine, tyrosine, essential amino acids, total oil content, linoleic acid and oleic acid content were the major parameters contributing significantly to genetic diversity. Present findings indicate that significant diversity exists for nutritional parameters in amaranth germplasm. The promising accessions with higher multiple nutritive traits; protein content (>16%), oil content (>11%), lysine content (>7.5 g/16 g N) and EAA higher than the FAO reported values, were identified. This is the first report on detailed nutritional analysis of diversity collected worldwide. These could be used as potential breeding material for nutritional enhancement through genetic improvement. This will help in overcoming the “triple burden” of malnourishment, hidden hunger, and obesity. 相似文献
The genus Zanthoxylum, belonging to Rutaceae, has a long history of cultivation both for economic and chemical values in China. To effectively conserve and sustainably utilize this genus resource, a study on genetic diversity and relationships of Zanthoxylum germplasms was carried out by employing SRAP markers. We used 16 primer combinations to assess genetic variations and relationships among 175 accessions from eight cultivated provenances, including Shandong, Henan, Shanxi, Shaanxi, Gansu, Sichuan, Guizhou and Yunnan. A total of 145 clear repetitive and intense bands were yielded, and the percentage of polymorphic bands was 100 % for per primer combination, indicating a relatively high diversity among Zanthoxylum germplasms. From a geographic perspective, the highest genetic diversity level was observed within Guizhou provenance (Na = 1.97, Ne = 1.52, H = 0.31, I = 0.46) while Henan provenance had the lowest genetic diversity (Na = 1.68, Ne = 1.45, H = 0.25, I = 0.37). Based on AMOVA results, the abundant genetic variation was mainly caused by variation of intra-provenances (84.96 %), rather than among provenances (15.038 %). The results indicated low genetic differentiation (Gst = 0.133) and high gene flow (Nm = 3.2605) among provenances. The neighbor-joining tree revealed that the 175 accessions could be divided into four groups, and groupings indicated a divergence between the cultivated accessions of Zanthoxylum bungeanum Maxim. and Z. armatum DC. Moreover, three accessions of Z. piperitum DC. var. inerme without prickles introduced from Japan gathered one cluster. Cluster IV is composed of accessions of different geographical origin, including 11 wild species and 10 cultivated accessions of Z. bungeanum. The cluster analysis also reflected a relatively close relationship between the geographical origins and the classification of accessions in cluster I. Structure analysis indicated that collected Zanthoxylum accessions could be divided into two major groups. The information obtained from our research would benefit to make use of Zanthoxylum germplasms and assist the management of a Zanthoxylum germplasms collection. 相似文献
