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1.
PLoS One ; 15(8): e0236351, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785293

RESUMO

Hybrid performance during wheat breeding can be improved by analyzing genetic distance (GD) among wheat genotypes and determining its correlation with heterosis. This study evaluated the GD between 16 wheat genotypes by using 60 simple sequence repeat (SSR) markers to classify them according to their relationships and select those with greater genetic diversity, evaluate the correlation of the SSR marker distance with heterotic performance and specific combining ability (SCA) for heat stress tolerance, and identify traits that most influence grain yield (GY). Eight parental genotypes with greater genetic diversity and their 28 F1 hybrids generated using diallel crossing were evaluated for 12 measured traits in two seasons. The GD varied from 0.235 to 0.911 across the 16 genotypes. Cluster analysis based on the GD estimated using SSRs classified the genotypes into three major groups and six sub-groups, almost consistent with the results of principal coordinate analysis. The combined data indicated that five hybrids showed 20% greater yield than mid-parent or better-parent. Two hybrids (P2 × P4) and (P2 × P5), which showed the highest performance of days to heading (DH), grain filling duration (GFD), and GY, and had large genetic diversity among themselves (0.883 and 0.911, respectively), were deemed as promising heat-tolerant hybrids. They showed the best mid-parent heterosis and better-parent heterosis (BPH) for DH (-11.57 and -7.65%; -13.39 and -8.36%, respectively), GFD (12.74 and 12.17%; 12.09 and 10.59%, respectively), and GY (36.04 and 20.04%; 44.06 and 37.73%, respectively). Correlation between GD and each of BPH and SCA effects based on SSR markers was significantly positive for GFD, hundred kernel weight, number of kernels per spike, harvest index, GY, and grain filling rate and was significantly negative for DH. These correlations indicate that the performance of wheat hybrids with high GY and earliness could be predicted by determining the GD of the parents by using SSR markers. Multivariate analysis (stepwise regression and path coefficient) suggested that GFD, hundred kernel weight, days to maturity, and number of kernels per spike had the highest influence on GY.


Assuntos
Resposta ao Choque Térmico/genética , Vigor Híbrido/genética , Seleção Genética/genética , Triticum/genética , Pão , Cruzamento , Grão Comestível/genética , Grão Comestível/crescimento & desenvolvimento , Flores/genética , Flores/crescimento & desenvolvimento , Genótipo , Humanos , Hibridização Genética/genética , Repetições de Microssatélites/genética , Fenótipo , Triticum/crescimento & desenvolvimento
2.
PLoS One ; 15(8): e0237774, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32797075

RESUMO

The source-sink relationship determines the ultimate grain yield of rice. In this study, we used a set of reciprocal introgression lines (ILs) derived from Xuishui09 × IR2061 to map quantitative trait loci (QTLs) that were associated with sink-, source-, and grain yield-related traits. A total of 95 QTLs influencing eight measured traits were identified using 6181 high-quality single nucleotide polymorphism markers. Nine background-independent QTLs were consistently detected in seven chromosomal regions in different genetic backgrounds. Seven QTLs clusters simultaneously affected sink-, source-, and grain yield-related traits, probably due to the genetic basis of significant correlations of grain yield with source and sink traits. We selected 15 candidate genes in the four QTLs consistently identified in the two populations by performing gene-based association and haplotype analyses using 2288 accessions from the 3K project. Among these, LOC_Os03g48970 for qTSN3b, LOC_Os06g04710 for qFLL6a, and LOC_Os07g32510 for qTGW7 were considered as the most likely candidate genes based on functional annotations. These results provide a basis for further study of candidate genes and for the development of high-yield rice varieties by balancing source-sink relationships using marker-assisted selection.


Assuntos
Grão Comestível/genética , Oryza/genética , Locos de Características Quantitativas , Cromossomos de Plantas/genética , Grão Comestível/crescimento & desenvolvimento , Genes de Plantas , Oryza/crescimento & desenvolvimento , Polimorfismo de Nucleotídeo Único
3.
Nat Commun ; 11(1): 2700, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32483115

RESUMO

Northern China harbored the world's earliest complex societies based on millet farming, in two major centers in the Yellow (YR) and West Liao (WLR) River basins. Until now, their genetic histories have remained largely unknown. Here we present 55 ancient genomes dating to 7500-1700 BP from the YR, WLR, and Amur River (AR) regions. Contrary to the genetic stability in the AR, the YR and WLR genetic profiles substantially changed over time. The YR populations show a monotonic increase over time in their genetic affinity with present-day southern Chinese and Southeast Asians. In the WLR, intensification of farming in the Late Neolithic is correlated with increased YR affinity while the inclusion of a pastoral economy in the Bronze Age was correlated with increased AR affinity. Our results suggest a link between changes in subsistence strategy and human migration, and fuel the debate about archaeolinguistic signatures of past human migration.


Assuntos
Agricultura/métodos , Produtos Agrícolas/crescimento & desenvolvimento , Grão Comestível/crescimento & desenvolvimento , Genoma Humano , Migração Humana , Arqueologia/métodos , Grupo com Ancestrais do Continente Asiático/genética , Grupo com Ancestrais do Continente Asiático/estatística & dados numéricos , China , DNA Antigo/análise , Genética Populacional/métodos , Geografia , Humanos , Dinâmica Populacional , Rios , Análise de Sequência de DNA/métodos , Fatores de Tempo
4.
PLoS One ; 15(6): e0234546, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32589642

RESUMO

Perennial crops in agricultural systems can increase sustainability and the magnitude of ecosystem services, but yield may depend upon biotic context, including soil mutualists, pathogens and cropping diversity. These biotic factors themselves may interact with abiotic factors such as drought. We tested whether perennial crop yield depended on soil microbes, water availability and crop diversity by testing monocultures and mixtures of three perennial crop species: a novel perennial grain (intermediate wheatgrass-Thinopyrum intermedium-- that produces the perennial grain Kernza®), a potential perennial oilseed crop (Silphium intregrifolium), and alfalfa (Medicago sativa). Perennial crop performance depended upon both water regime and the presence of living soil, most likely the arbuscular mycorrhizal (AM) fungi in the whole soil inoculum from a long term perennial monoculture and from an undisturbed native remnant prairie. Specifically, both Silphium and alfalfa strongly benefited from AM fungi. The presence of native prairie AM fungi had a greater benefit to Silphium in dry pots and alfalfa in wet pots than AM fungi present in the perennial monoculture soil. Kernza did not benefit from AM fungi. Crop mixtures that included Kernza overyielded, but overyielding depended upon inoculation. Specifically, mixtures with Kernza overyielded most strongly in sterile soil as Kernza compensated for poor growth of Silphium and alfalfa. This study identifies the importance of soil biota and the context dependence of benefits of native microbes and the overyielding of mixtures in perennial crops.


Assuntos
Agricultura , Medicago sativa/fisiologia , Plantas Daninhas/crescimento & desenvolvimento , Estresse Fisiológico/fisiologia , Biota/fisiologia , Produtos Agrícolas/fisiologia , Ecossistema , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/microbiologia , Micorrizas/fisiologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Poaceae/crescimento & desenvolvimento , Poaceae/microbiologia , Microbiologia do Solo , Simbiose/fisiologia
5.
J Vis Exp ; (159)2020 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-32510514

RESUMO

The characterization of gene expression is dependent on RNA quality. In germinating, developing and mature cereal seeds, the extraction of high-quality RNA is often hindered by high starch and sugar content. These compounds can reduce both the yield and the quality of the extracted total RNA. The deterioration in quantity and quality of total RNA can subsequently have a significant impact on the downstream transcriptomic analyses, which may not accurately reflect the spatial and/or temporal variation in the gene expression profile of the samples being tested. In this protocol, we describe an optimized method for extraction of total RNA with sufficient quantity and quality to be used for whole transcriptome analysis of cereal grains. The described method is suitable for several downstream applications used for transcriptomic profiling of developing, germinating, and mature cereal seeds. The method of transcriptome profiling using a microarray platform is shown. This method is specifically designed for gene expression profiling of cereals with described genome sequences. The detailed procedure from microarray handling to final quality control is described. This includes cDNA synthesis, cRNA labelling, microarray hybridization, slide scanning, feature extraction, and data quality validation. The data generated by this method can be used to characterize the transcriptome of cereals during germination, in various stages of grain development, or at different biotic or abiotic stress conditions. The results presented here exemplify high-quality transcriptome data amenable for downstream bioinformatics analyses, such as the determination of differentially expressed genes (DEGs), characterisation of gene regulatory networks, and conducting transcriptome-wide association study (TWAS).


Assuntos
Grão Comestível/genética , Perfilação da Expressão Gênica/métodos , Sementes/genética , Mapeamento Cromossômico , Biologia Computacional , Grão Comestível/crescimento & desenvolvimento , Redes Reguladoras de Genes , Germinação , Análise de Sequência com Séries de Oligonucleotídeos , Controle de Qualidade , Sementes/crescimento & desenvolvimento
6.
PLoS One ; 15(5): e0229372, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32433686

RESUMO

We report the earliest and the most abundant archaeobotanical assemblage of southwest Asian grain crops from Early Bronze Age Central Asia, recovered from the Chap II site in Kyrgyzstan. The archaeobotanical remains consist of thousands of cultivated grains dating to the mid-late third millennium BCE. The recovery of cereal chaff and weeds suggest local cultivation at 2000 m.a.s.l., as crops first spread to the mountains of Central Asia. The site's inhabitants possibly cultivated two types of free-threshing wheats, glume wheats, and hulled and naked barleys. Highly compact caryopses of wheat and barley grains represent distinct morphotypes of cereals adapted to highland environments. While additional macrobotanical evidence is needed to confirm the presence of glume wheats at Chap II, the possible identification of glume wheats at Chap II may represent their most eastern distribution in Central Asia. Based on the presence of weed species, we argue that the past environment of Chap II was characterized by an open mountain landscape, where animal grazing likely took place, which may have been further modified by people irrigating agricultural fields. This research suggests that early farmers in the mountains of Central Asia cultivated compact morphotypes of southwest Asian crops during the initial eastward dispersal of agricultural technologies, which likely played a critical role in shaping montane adaptations and dynamic interaction networks between farming societies across highland and lowland cultivation zones.


Assuntos
Arqueologia , Produtos Agrícolas/história , Grão Comestível/história , Ásia , Produtos Agrícolas/crescimento & desenvolvimento , Grão Comestível/crescimento & desenvolvimento , História Antiga , Hordeum/crescimento & desenvolvimento , Milhetes/crescimento & desenvolvimento , Triticum/crescimento & desenvolvimento
7.
PLoS One ; 15(5): e0232974, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32401803

RESUMO

Heat stress along with low water availability at reproductive stage (terminal growth phase of wheat crop) is major contributing factor towards less wheat production in tropics and sub-tropics. Flag leaf plays a pivotal role in assimilate partitioning and stress tolerance of wheat during terminal growth phase. However, limited is known about biochemical response of flag leaf to combined and individual heat and drought stress during terminal growth phase. Therefore, current study investigated combined and individual effect of terminal drought and heat stress on water relations, photosynthetic pigments, osmolytes accumulation and antioxidants defense mechanism in flag leaf of bread wheat. Experimental treatments comprised of control, terminal drought stress alone (50% field capacity during reproductive phase), terminal heat stress alone (wheat grown inside plastic tunnel during reproductive phase) and terminal drought stress + terminal heat stress. Individual and combined imposition of drought and heat stresses significantly (p≤0.05) altered water relations, osmolyte contents, soluble proteins and sugars along with activated antioxidant defensive system in terms of superoxide dismutase (SOD), peroxidase (POD) and ascorbate peroxidase (APX). Turgor potential, POD and APX activities were lowest under individual heat stress; however, these were improved when drought stress was combined with heat stress. It is concluded that combined effect of drought and heat stress was more detrimental than individual stresses. The interactive effect of both stresses was hypo-additive in nature, but for some traits (like turgor potential and APX) effect of one stress neutralized the other. To best of our knowledge, this is the first report on physiological and biochemical response of flag leaf of wheat to combine heat and drought stress. These results will help future studies dealing with improved stress tolerance in wheat. However, detailed studies are needed to fully understand the genetic mechanisms behind these physiological and biochemical changes in flag leaf in response to combined heat and drought stress.


Assuntos
Triticum/crescimento & desenvolvimento , Triticum/fisiologia , Antioxidantes/metabolismo , Pão , Clorofila/metabolismo , Secas , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/fisiologia , Resposta ao Choque Térmico/fisiologia , Fotossíntese , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Água/metabolismo
8.
PLoS One ; 15(4): e0232164, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32330189

RESUMO

Maize (Zea mays L) is one of main nutrients sources for humans and animals worldwide. In Africa, storage of maize ensures food resources availability throughout the year. However, it often suffers losses exceeding 20% due to insects such as the larger grain borer, Prostephanus truncatus (Horn) (Coleoptera; Bostrichidae), major pest of stored maize in the tropical countries. This study aims to select resistant varieties to reduce maize storage losses and explain the physicochemical parameters role in grains susceptibility. In the first study, maize grains were artificially infested under no-choice method with insects. Susceptibility parameters such as weight loss, grain damage, number of emerged insects, median development time and susceptibility index varied significantly through maize varieties. Dobie susceptibility index (SI) was assessed as a major indicator of resistance. The most resistant varieties were Early-Thaï, DMR-ES and Tzee-Yellow. Conversely, Synth-9243, Obatampa and Synth-C varieties were susceptible. SWAN, Across-Pool and Tzee-White were classified as moderately resistant varieties. The insect reproductive potential was significantly different in the nine maize varieties and Early-Thaï, DMR-ES and Tzee-Yellow varieties were the least favourable host. To assess the relationship between grains physicochemical characteristics and varietal susceptibility, moisture, total phenolics, palmitic acid, proteins, amylose, density and grain hardness were evaluated according to standardized methods. Palmitic acid, SI, insects emerged and grain damage were significantly and positively correlated with each other, and negatively correlated with grains hardness, phenolics and amylose contents. Maize susceptibility index was significantly and negatively correlated to amylose, and phenolics contents and positively correlated to palmitic acid content. This study identified three resistant maize varieties to P. tuncatus and revealed that the major factors involved in this resistance were hardness, phenolic and amylose contents of grains.


Assuntos
Besouros/patogenicidade , Zea mays/crescimento & desenvolvimento , Zea mays/parasitologia , África , Amilose/metabolismo , Animais , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/metabolismo , Ácido Palmítico/metabolismo , Fenol/metabolismo , Estruturas Vegetais/crescimento & desenvolvimento , Estruturas Vegetais/metabolismo , Estruturas Vegetais/parasitologia , Zea mays/metabolismo
9.
PLoS One ; 15(4): e0229535, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32315299

RESUMO

Colored wheat is a valuable resource that is rich in anthocyanins and minerals and thus contributes additional nutritional value to a healthy human diet. However, the effects of nitrogen fertilization on anthocyanin content (AC) and the balance between quality and yield still merit discussion. In this study, blue, purple, and common-colored wheat genotypes were used to investigate three nutrient quality traits, seven processing quality traits, three yield traits and seven grain morphology traits at three nitrogen levels in two years to excavate their possible plasticity under low-nitrogen stress and the tradeoffs among these traits. The highest AC was found in the blue genotypes followed by the purple genotypes. Analysis of variance (ANOVA) showed that AC could be significantly increased by reducing N application, especially in the purple genotypes. Therefore, growing colored wheat with low nitrogen input could allow efficient harvesting of grain with higher AC. However, the other nutrient quality traits and most processing quality traits were observed to decrease under low-nitrogen (LN) stress. Additionally, a correlation analysis indicated that the nutrient quality traits had stable tradeoffs with thousand kernel weight at all N levels because of the significantly negative correlations among them. Therefore, the additive main effect and multiplicative interaction (AMMI) model was used to further identify the most suitable colored genotypes with the best yield potential and also nutrient quality relative characteristics under LN stress. The blue lines Lanmai2999 and purple varieties Zhongkezinuomai 168 were found to be specifically adapted to LN stress with the highest AC values and showed stable performance in the other nutrient quality- and yield-related features. To further investigate the possible mechanism of anthocyanin accumulation in response to reduced N application, the expression of four genes (TaCHS, TaFDR, TaCHI and TaANS) involved in the anthocyanin synthesis pathway was evaluated. All four genes were downregulated under high nitrogen fertilizer application, indicating that anthocyanin synthesis in colored wheat might be inhibited by nitrogen fertilizer. Therefore, this research provided information for optimizing nitrogen fertilizer management in producing colored wheat and also demonstrated that it is efficient and economical to plant colored wheat genotypes in nitrogen-poor areas for use in a healthy human diet, improving the benefits of wheat planting and facilitating nitrogen pollution control.


Assuntos
Antocianinas/genética , Grão Comestível/genética , Nitrogênio/metabolismo , Triticum/genética , Grão Comestível/crescimento & desenvolvimento , Fertilizantes , Regulação da Expressão Gênica de Plantas/genética , Genótipo , Glutens/metabolismo , Humanos , Nutrientes , Fenótipo , Melhoramento Vegetal , Proteínas de Plantas/genética , Triticum/crescimento & desenvolvimento
10.
PLoS One ; 15(4): e0221603, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32343696

RESUMO

Increased genetic gain for complex traits in plant breeding programs can be achieved through different selection strategies. The objective of this study was to compare potential gains for grain yield in a winter wheat breeding program through estimating response to selection R values across several selection approaches including phenotypic (PS), marker-based (MS), genomic (GS), and a combination of PS and GS (PS+GS). Ten populations of Washington State University (WSU) winter wheat breeding lines including a diversity panel and F5 and double haploid lines evaluated from 2015 to 2019 growing seasons for grain yield in Lind and Pullman, WA, USA were used in the study. Selection was conducted by selecting the top 20% of lines based on observed yield (PS strategy), genomic estimated breeding values (GS), presence of yield "enhancing" alleles of the most significant single nucleotide polymorphism (SNP) markers identified from genome-wide association mapping (MS), and high observed yield and estimated breeding values (PS+GS). Overall, PS compared to other individual selection strategies (MS and GS) showed the highest mean response (R = 0.61) within the same environment. When combined with GS, a 23% improvement in R for yield was observed, indicating that gains could be improved by complementing traditional PS with GS within the same environment. Validating selection strategies in different environments resulted in low to negative R values indicating the effects of genotype-by-environment interactions for grain yield. MS was not successful in terms of R relative to the other selection approaches; using this strategy resulted in a significant (P < 0.05) decrease in response to selection compared with the other approaches. An integrated PS+GS approach could result in optimal genetic gain within the same environment, whereas a PS strategy might be a viable option for grain yield validated in different environments. Altogether, we demonstrated that gains through increased response to selection for yield could be achieved in the WSU winter wheat breeding program by implementing different selection strategies either exclusively or in combination.


Assuntos
Melhoramento Vegetal/métodos , Triticum/crescimento & desenvolvimento , Grão Comestível/genética , Grão Comestível/crescimento & desenvolvimento , Genoma de Planta , Genômica , Haploidia , Polimorfismo de Nucleotídeo Único , Estações do Ano , Seleção Genética , Triticum/genética
11.
Ecotoxicol Environ Saf ; 196: 110525, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32224370

RESUMO

Fragrant rice is a high-valued quality rice type which is gaining much popularity over the globe due to its better cooking qualities and special aromatic characteristics. Selenium (Se) and silicon (Si) could improve the growth and yield of rice; however, the combine effects of Se and Si (Se-Si treatments) on rice grain quality, aroma and lodging in fragrant rice were rarely investigated. The pot and field experiments were conducted with two fragrant rice cultivars i.e., Xiangyaxiangzhan and Yuxiangyouzhan, grown under three Se levels i.e., 0, 120, and 240 mg kg-1 of soil (for pot experiment) and 0, 300, and 600 kg ha-1 (for field experiment) regarded as LSe, MSe and HSe, respectively and two Si levels i.e., 0 and 60 mg kg-1 of soil (for pot experiment) and 0 and 150 kg ha-1 (for field experiment) regarded as -Si and +Si, respectively. Results depicted that the Se-Si treatments regulated head rice yield, grain yield and yield related traits and the HSe+Si treatment sustainably improved the grain yield and head rice yield by regulating plant growth, antioxidant response and malondialdehyde (MDA) contents in fragrant rice. The Se-Si treatments also improved the grain 2AP contents owing to regulation in the proline, pyrroline-5-carboxylate (P5C) and γ-aminobutyric acid (GABA) contents. Besides, Se-Si treatments also regulated the grain quality attributes and influenced the plant Se contents. Moreover, the Si mitigated Se-induced lodging resulted from changes in the lodging parameters i.e., lodging index, fresh weight per tiller, pushing resistance force, plant height and bending moment. Overall, the Se and Si application improved the grain yield and regulated the dry weight accumulation, antioxidant attributes and quality attributes. Meanwhile, the Si application mitigated the negative effect of Se-induced lodging in fragrant rice.


Assuntos
Grão Comestível/efeitos dos fármacos , Odorantes/análise , Oryza/efeitos dos fármacos , Selênio/farmacologia , Silício/farmacologia , Antioxidantes/análise , Relação Dose-Resposta a Droga , Grão Comestível/química , Grão Comestível/crescimento & desenvolvimento , Malondialdeído/análise , Oryza/química , Oryza/crescimento & desenvolvimento , Prolina/análise , Pirróis/análise , Solo/química
12.
Artigo em Inglês | MEDLINE | ID: mdl-32348929

RESUMO

Grain filling is the final determinant of yield, and this process is susceptible to abiotic stresses. Salicylic acid (SA) regulates grain filling in rice plants. A comparative proteomic study was conducted to understand how SA mediates grain filling under soil drying (SD) condition. Zhefu802 and its near-isogenic line (NIL) were planted in pots in an artificial chamber. SA (100 mg L-1) was applied, followed by SD treatment (with a water potential of -30 to -35 kPa) at anthesis. The results showed that the grain yield and grain weight significantly decreased under SD in Zhefu802, but not in its NIL variety. SD also decreased expression of photosynthesis-related proteins in grains of Zhefu802, which resulted in its poorer drought resistance. Furthermore, the decreased grain filling rate rather than the grain size explained the observed decreased grain weight and grain yield under SD. Interestingly, these reductions were reversed by SA. Expression of proteins involved in glycolysis/TCA circle, starch and sucrose metabolism, antioxidation and detoxication, oxidative phosphorylation, transcription, translation, and signal transduction, were significantly down-regulated under SD and were significantly up-regulated in response to SA. The expression of these proteins was examined at transcriptional level and similar results were obtained. Inhibited expression of these proteins and related pathways contributed to the observed decrease in the grain filling rate of Zhefu802, and application of SA up-regulated expression of these proteins to improve grain weight. The findings of this study provide new insights into grain filling regulation by SA, and offer the scientific foundation for cultivation practice.


Assuntos
Grão Comestível , Oryza , Proteoma , Ácido Salicílico , Grão Comestível/genética , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/metabolismo , Oryza/genética , Oryza/metabolismo , Proteômica , Ácido Salicílico/metabolismo , Solo/química
13.
J Appl Microbiol ; 129(3): 575-589, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32147927

RESUMO

OBJECTIVE: The present study was performed to examine the role of pqqE inhabiting rhizobacteria in organic acid production and relationship of the organic acids with phosphate solubilization by the bacteria in vitro as well as in vivo. METHODS AND RESULTS: The pqqE gene was PCR amplified and sequenced in genomic DNA of Pantoea sp. WP-5 and Pseudomonas sp. NN-4. Nucleotide sequence obtained from WP-5 and NN-4 showed maximum sequence similarity (88 and 89%, respectively) with the pqqE gene of Pseudomonas fluorescens strain CMR12a (KM251420). Deduced amino acid sequence from pqqE gene of Pseudomonas sp. NN-4 and Pantoea sp. WP-5 showed 75 and 93% similarity, respectively, with protein pyrroloquinoline quinone. Phosphate solubilization and acid production assay were quantified on spectrophotometer and high-profile liquid chromatograph, respectively, by each bacterial strain. Both strains produced organic acids such as acetic, citric, gluconic, succinic and malic acid and lowered the pH of Pikovskaya broth medium under laboratory conditions. Phosphate solubilization by Pantoea sp. WP-5 was 311 ± 4 and 204 ± 3 µg ml-1 in the culture medium supplemented with glucose and sucrose as carbon source, respectively. Pseudomonas sp. NN-4 solubilized 176 ± 3 and 298 ± 5 µg ml-1 phosphate in Pikovskaya broth medium under similar conditions. In field experiments conducted during two consecutive years, the concentration of acetic acid and gluconic acid was higher in root exudates of plants treated with Pantoea sp. WP-5 at 30% reduced doses of nitrogen (N)- and phosphorus (P)-based chemical fertilizers as compared to non-inoculated plants. Values of chlorophyll contents, crop growth rate, leaf area index, straw yield and P contents were recorded higher in plants inoculated with Pantoea sp. WP-5 and Pseudomonas sp. NN-4 as compared to non-inoculated control. Grain yield was increased by 10-12% due to inoculation with Pantoea sp. WP-5 and Pseudomonas sp. NN-4 over non-inoculated control in the field experiments. CONCLUSIONS: These results lead to the conclusions that the rhizobacteria inhabiting pqqE gene produced organic acids and solubilized the phosphate in vitro. On inoculation to wheat plants in field experiments, these strains produced the organic acids, solubilized the phosphate, and improved the P uptake and productivity of wheat. SIGNIFICANCE AND IMPACT OF THE STUDY: The Pantoea sp. WP-5 and Pseudomonas sp. NN-4 are the potential candidates for inoculation to wheat as phosphate solubilizer even with reduced chemical fertilizer dose. The inoculation of the strains may enhance grain yield and net income of the farmer even with less chemical fertilizer application. This practice will be helpfull inminimizing environmental pollution.


Assuntos
Proteínas de Bactérias/genética , Pantoea/fisiologia , Pseudomonas/fisiologia , Triticum/crescimento & desenvolvimento , Triticum/microbiologia , Ácidos/metabolismo , Proteínas de Bactérias/metabolismo , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/metabolismo , Fertilizantes/análise , Pantoea/genética , Pantoea/metabolismo , Fosfatos/metabolismo , Pseudomonas/genética , Pseudomonas/metabolismo , Solo/química , Microbiologia do Solo , Triticum/metabolismo
14.
J Appl Microbiol ; 129(3): 680-694, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32176428

RESUMO

AIM: To evaluate biological control agents (BCAs) against Fusarium graminearum on infected maize stalks as a means to reduce Fusarium head blight (FHB) in subsequently grown wheat. METHODS AND RESULTS: In the laboratory, BCAs were applied against F. graminearum on maize stalk pieces. Clonostachys rosea inhibited the perithecia development and ascospore discharge when applied before, simultaneously with and after the pathogen. In the field, we simulated a system with high disease pressure, that is, a maize-wheat rotation under no-tillage, by preparing maize stalks inoculated with F. graminearum. The infected stalks were treated with formulations of C. rosea selected in vitro or the commercial BCA strain Trichoderma atrobrunneum ITEM908 and exposed to field conditions over winter and spring between winter wheat rows. Monitoring with spore traps and of FHB symptoms, as well as quantification of F. graminearum incidence and DNA in harvested grain revealed significant reductions by C. rosea by up to 85, 91, 69 and 95% compared with an inoculated but untreated positive control, respectively. Deoxynivalenol (DON) and zearalenone (ZEN) contents were reduced by up to 93 and 98%, respectively. Treatments with T. atrobrunneum were inconsistent, with significant reductions of DON and ZEN under warm and wet climatic conditions only. CONCLUSIONS: The findings support the application of C. rosea against F. graminearum on residues of maize to suppress the primary inoculum of FHB. SIGNIFICANCE AND IMPACT OF THE STUDY: As sustainable agriculture requires solutions to control FHB, hence, the application of C. rosea during the mulching of maize crop residues should be evaluated in on-farm experiments.


Assuntos
Fusarium/patogenicidade , Controle Biológico de Vetores/métodos , Doenças das Plantas/prevenção & controle , Triticum/microbiologia , Zea mays/microbiologia , Grão Comestível/química , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/microbiologia , Hypocreales/fisiologia , Micotoxinas/análise , Doenças das Plantas/microbiologia , Esporos Fúngicos/patogenicidade , Trichoderma/fisiologia , Triticum/química , Triticum/crescimento & desenvolvimento , Zea mays/química
15.
Nat Commun ; 11(1): 988, 2020 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-32080171

RESUMO

Increasing grain yield of maize (Zea mays L.) is required to meet the rapidly expanding demands for maize-derived food, feed, and fuel. Breeders have enhanced grain productivity of maize hybrids by pyramiding desirable characteristics for larger ears. However, loci selected for improving grain productivity remain largely unclear. Here, we show that a serine/threonine protein kinase encoding gene KERNEL NUMBER PER ROW6 (KNR6) determines pistillate floret number and ear length. Overexpression of KNR6 or introgression of alleles lacking the insertions of two transposable elements in the regulatory region of KNR6 can significantly enhance grain yield. Further in vitro evidences indicate that KNR6 can interact with an Arf GTPase-activating protein (AGAP) and its phosphorylation by KNR6 may affect ear length and kernel number. This finding provides knowledge basis to enhance maize hybrids grain yield.


Assuntos
Proteínas de Plantas/genética , Proteínas Serina-Treonina Quinases/genética , Zea mays/genética , Mapeamento Cromossômico , Grão Comestível/enzimologia , Grão Comestível/genética , Grão Comestível/crescimento & desenvolvimento , Proteínas Ativadoras de GTPase/metabolismo , Genes de Plantas , Fenótipo , Fosforilação , Melhoramento Vegetal , Proteínas de Plantas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Locos de Características Quantitativas , Zea mays/enzimologia , Zea mays/crescimento & desenvolvimento
16.
Ecotoxicol Environ Saf ; 191: 110218, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31962215

RESUMO

Heavy metals contamination of soil especially with cadmium (Cd) is a serious environmental concern in the current industrial era. Biochar serves as an excellent ameliorating agent depending upon its properties and application rates. In the pot scale study, effect of acid treated (AWSB) and untreated wheat straw biochar (WSB) was studied on physiology, grain yield, Cd accumulation, and tolerance of quinoa with possible health risks. Different levels of Cd (0, 25, 50 and 75 mg kg-1), AWSB and WSB (1% and 2% (w/w)) were applied in soil. Accumulation of Cd in control plant tissues led to oxidative stress which was shown in terms of increased lipid peroxidation. While biochar application relieved the oxidative damage as confirmed by the low production of H2O2 and TBARS contents. Application of AWSB improved plant growth, pigment contents and gas exchange attributes by limiting the accumulation of Cd in root, shoot and grain of quinoa. Results revealed a significant improvement in the activity of superoxide (SOD), catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POD) with biochar at elevated levels of Cd in soil. Target Hazard Quotient (THQ) remained < 1 in the quinoa grains with WSB and AWSB under Cd stress. These results revealed that AWSB most effectively alleviated Cd toxicity in quinoa thereby decreasing Cd accumulation and regulation of Cd induced oxidative stress triggered by the antioxidant enzymatic system.


Assuntos
Ácidos/química , Cádmio/metabolismo , Carvão Vegetal/farmacologia , Chenopodium quinoa/efeitos dos fármacos , Poluentes do Solo/metabolismo , Antioxidantes/metabolismo , Cádmio/análise , Carvão Vegetal/química , Chenopodium quinoa/crescimento & desenvolvimento , Chenopodium quinoa/metabolismo , Grão Comestível/efeitos dos fármacos , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Solo/química , Poluentes do Solo/análise , Triticum/química
17.
Electron. j. biotechnol ; 43: 8-15, Jan. 2020. tab
Artigo em Inglês | LILACS | ID: biblio-1087467

RESUMO

Background: Plant tissue cultures have the potential to reprogram the development of microspores from normal gametophytic to sporophytic pathway resulting in the formation of androgenic embryos. The efficiency of this process depends on the genotype, media composition and external conditions. However, this process frequently results in the regeneration of albino instead of green plants. Successful regeneration of green plants is affected by the concentration of copper sulfate (CuSO4) and silver nitrate (AgNO3) and the length of induction step. In this study, we aimed at concurrent optimization of these three factors in barley (Hordeum vulgare L.), wheat (Triticum aestivum L.), and triticale (x Triticosecale spp. Wittmack ex A. Camus 1927) using the Taguchi method. We evaluated uniform donor plants under varying experimental conditions of in vitro anther culture using the Taguchi approach, and verified the optimized conditions. Results: Optimization of the regeneration conditions resulted in an increase in the number of green regenerants compared with the control. Statistic Taguchi method for optimization of the in vitro tissue culture plant regeneration via anther cultures allowed reduction of the number of experimental designs from 27 needed if full factorial analysis is used to 9. With the increase in the number of green regenerants, the number of spontaneous doubled haploids decreased. Moreover, in barley and triticale, the number of albino regenerants was reduced. Conclusion: The statistic Taguchi approach could be successfully used for various factors (here components of induction media, time of incubation on induction media) at a one time, that may impact on cereals anther cultures to improve the regeneration efficiency


Assuntos
Cultivos Agrícolas , Grão Comestível/crescimento & desenvolvimento , Modelos Estatísticos , Pigmentos Biológicos , Reguladores de Crescimento de Planta , Pólen , Nitrato de Prata , Cor , Sulfato de Cobre , Androgênios
18.
PLoS One ; 15(1): e0223086, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31899771

RESUMO

Rice wild relatives (RWR) constitute an extended gene pool that can be tapped for the breeding of novel rice varieties adapted to abiotic stresses such as iron (Fe) toxicity. Therefore, we screened 75 Oryza genotypes including 16 domesticated O. sativa genotypes, one O. glaberrima, and 58 RWR representing 21 species, for tolerance to Fe toxicity. Plants were grown in a semi-artificial greenhouse setup, in which they were exposed either to control conditions, an Fe shock during the vegetative growth stage (acute treatment), or to a continuous moderately high Fe level (chronic treatment). In both stress treatments, foliar Fe concentrations were characteristic of Fe toxicity, and plants developed foliar stress symptoms, which were more pronounced in the chronic Fe stress especially toward the end of the growing season. Among the genotypes that produced seeds, only the chronic stress treatment significantly reduced yields due to increases in spikelet sterility. Moreover, a moderate but non-significant increase in grain Fe concentrations, and a significant increase in grain Zn concentrations were seen in chronic stress. Both domesticated rice and RWR exhibited substantial genotypic variation in their responses to Fe toxicity. Although no RWR strikingly outperformed domesticated rice in Fe toxic conditions, some genotypes scored highly in individual traits. Two O. meridionalis accessions were best in avoiding foliar symptom formation in acute Fe stress, while an O. rufipogon accession produced the highest grain yields in both chronic and acute Fe stress. In conclusion, this study provides the basis for using interspecific crosses for adapting rice to Fe toxicity.


Assuntos
Resistência à Doença/genética , Ferro/toxicidade , Oryza/genética , Doenças das Plantas/genética , Animais , Grão Comestível/efeitos dos fármacos , Grão Comestível/genética , Grão Comestível/crescimento & desenvolvimento , Etanol , Genótipo , Oryza/efeitos dos fármacos , Oryza/crescimento & desenvolvimento , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Sementes/genética , Sementes/crescimento & desenvolvimento , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética
19.
Int J Mol Sci ; 21(2)2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31952130

RESUMO

Understanding the genetic basis of maize grain yield and other traits under low-nitrogen (N) stressed environments could improve selection efficiency. In this study, five doubled haploid (DH) populations were evaluated under optimum and N-stressed conditions, during the main rainy season and off-season in Kenya and Rwanda, from 2014 to 2015. Identifying the genomic regions associated with grain yield (GY), anthesis date (AD), anthesis-silking interval (ASI), plant height (PH), ear height (EH), ear position (EPO), and leaf senescence (SEN) under optimum and N-stressed environments could facilitate the use of marker-assisted selection to develop N-use-efficient maize varieties. DH lines were genotyped with genotyping by sequencing. A total of 13, 43, 13, 25, 30, 21, and 10 QTL were identified for GY, AD ASI, PH, EH, EPO, and SEN, respectively. For GY, PH, EH, and SEN, the highest number of QTL was found under low-N environments. No common QTL between optimum and low-N stressed conditions were identified for GY and ASI. For secondary traits, there were some common QTL for optimum and low-N conditions. Most QTL conferring tolerance to N stress was on a different chromosome position under optimum conditions.


Assuntos
Biomassa , Grão Comestível/genética , Nitrogênio/metabolismo , Estresse Fisiológico , Zea mays/genética , Adaptação Fisiológica/genética , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/metabolismo , Genótipo , Quênia , Fenótipo , Locos de Características Quantitativas , Chuva , Ruanda , Estações do Ano , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
20.
Ecotoxicol Environ Saf ; 189: 110008, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31796254

RESUMO

Excess iron (Fe) is commonly observed in wetland rice (Oryza sativa L.) plants, impairing crop growth and productivity. Some information suggests that silicon (Si) can reduce Fe content in leaves and roots of rice (vegetative phase), but nothing is known if Si could mitigate the effects of Fe toxicity on rice production and photosynthesis. Here, we assessed the role of Si in alleviating the well-known effects of Fe toxicity on nutritional imbalances, biomass accumulation, photosynthesis and grain yield using two rice cultivars having differential abilities to tolerate excess Fe. Plants were hydroponically grown under two Fe levels (25 µM or 5 mM) and the nutrient solutions were amended with Si (0 or 2 mM). Under excess Fe were detected (i) nutritional deficiencies, especially of calcium and magnesium in leaves; (ii) negligible changes in grain nutritional composition, independently of Si application; (iii) decreases in net photosynthetic rates, stomatal conductance and electron transport rate, in parallel to decreased grain yield components (total grain biomass, 1000-grain mass, percentage of filled grains, number of grains per plant and harvest index), especially in the Fe-sensitive cultivar. These impairments were partially reversed by the application of Si. Results also suggest that Si alleviated the negative impacts of Fe on spikelet sterility. In summary, we conclude that the use of Si can be recommended as an effective management strategy to reduce the negative impacts of Fe toxicity on rice photosynthetic performance and crop yield.


Assuntos
Grão Comestível/efeitos dos fármacos , Ferro/toxicidade , Oryza/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Silício/farmacologia , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/metabolismo , Transporte de Elétrons/efeitos dos fármacos , Hidroponia , Ferro/metabolismo , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/toxicidade
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