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1.
Equine Vet J ; 51(6): 756-759, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30868638

RESUMO

BACKGROUND: Salmonella enterica subspecies enterica serovar abortus equi (S. abortus equi) is well known as the aetiological agent of equine abortion. However, abortion caused by S. abortus equi has not been previously described in donkeys. OBJECTIVES: To investigate whether S. abortus equi was correlated with an abortion outbreak consisting of 61 abortions. STUDY DESIGN: Investigation of the clinical cases using pathoanatomical, bacteriological, serological and molecular approaches. METHODS: Autopsies on nine aborted foetuses were performed. Tissue specimens from seven aborted foetuses and two mares were cultured and subjected to detection of equine herpesvirus 1 (EHV-1), equine herpesvirus 4 (EHV-4) and equine arteritis virus (EAV) by polymerase chain reaction. The isolates were serotyped according to the Kaufmann-White scheme and analysed by multi-locus sequence typing (MLST). Detection of EHV and EAV antibodies was performed in all pregnant mares. RESULTS: No obvious gross lesions were observed in the foetuses. Nine Gram-negative isolates were obtained from all nine tissue samples and were identified as Salmonella spp. All of the isolates belonged to the B group, the O antigen epitope was 4, 12 and H antigen was not obtained. The isolates of Salmonella were characterised as sequence type (ST) 251. Detection of EHV-1, EHV-4 and EAV was negative. MAIN LIMITATIONS: The mechanism that causes abortion in donkeys needs further study and the lack of histological examination. CONCLUSION: Salmonella abortus equi was isolated as the single agent and was responsible for the abortions. Equine practitioners should be aware of S. abortus equi infection as a cause of abortion in donkeys.


Assuntos
Aborto Animal/microbiologia , Equidae , Complicações Infecciosas na Gravidez/veterinária , Salmonelose Animal/microbiologia , Salmonella/classificação , Aborto Animal/epidemiologia , Animais , China , Feminino , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Infecciosas na Gravidez/microbiologia , Salmonelose Animal/epidemiologia , Salmonelose Animal/patologia
2.
J Mycol Med ; 29(2): 120-126, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30898449

RESUMO

Apiotrichum mycotoxinivorans (formerly Trichosporon mycotoxinivorans) has long been used to degrade fungal toxins in livestock feed. However, clinic reports about this type of fungus are rare. In this study, we report the morphology, biochemistry, and molecular characteristics of an A. mycotoxinivorans strain isolated from a pediatric patient with congenital ventricular septal defect and pneumonia. A female patient, 26 months old, presented with congenital ventricular septal defect. Pulmonary infection symptoms were observed after the patient received cardiac repair surgery. Sputum bacterial and fungal cultures were positive for Elizabethkingia anophelis and a fungus, which was not readily identifiable using biochemical identification, or MALDI-TOF MS analysis. The strain was finally identified as A. mycotoxinivorans using amplification and sequencing of the D1/D2 region of 26S rDNA, ITS, and IGS1. Antifungal susceptibility test results suggested that fluconazole or voriconazole may be an appropriate choice for antifungal therapy. A biodegradability of ochratoxin A was considered as a characteristic of the fungal strain. Our results support the existing evidence that A. mycotoxinivorans is an opportunistic pathogen for human beings. Nucleic acid analysis allows for the accurate identification of the species in instances where conventional identification methods such as biochemical testing and MALDI-TOF MS may be unsuccessful.


Assuntos
Pneumonia/microbiologia , Escarro/microbiologia , Trichosporon/classificação , Trichosporon/isolamento & purificação , Tricosporonose/diagnóstico , Antifúngicos/farmacologia , Pré-Escolar , DNA Fúngico/genética , Feminino , Humanos , Técnicas de Tipagem Micológica , Filogenia , Trichosporon/efeitos dos fármacos , Tricosporonose/microbiologia
3.
Sci Rep ; 9(1): 3220, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30824770

RESUMO

Experiments were conducted to improve jenny conception rates through induced ovulation and timed insemination. Jennies in control, hCG and LH groups were injected intramuscularly with saline alone or saline containing hCG or LH, respectively, when the dominant follicle diameter reached 35 mm. Then, follicle development was checked every 8 h until the dominant follicle ovulated. While 76% of the hCG-treated jennies ovulated between 24 and 48 h, and 84% of the LH-treated ovulated between 24 and 40 h after injection, ovulations in control jennies scattered over an extended period after injection. Conception rates after insemination were significantly higher in LH- or hCG-treated jennies than in the conventionally-bred jennies. The LH preparation used in this study contained more FSH than the hCG preparation did, and supplementing the hCG treatment with FSH significantly improved ovulation synchronization. Ovulations in jennies treated on rainy days were significantly postponed and less synchronized compared to those in jennies treated on sunny days. Together, the results suggested that jenny conception could be significantly improved by inducing ovulation with LH or hCG treatment followed by timed insemination and that FSH and the weather during treatment had profound effects on ovulation induction of jennies.


Assuntos
Fertilização/efeitos dos fármacos , Hormônio Foliculoestimulante/farmacologia , Inseminação Artificial/métodos , Indução da Ovulação/métodos , Ovulação/efeitos dos fármacos , Animais , Gonadotropina Coriônica/administração & dosagem , Gonadotropina Coriônica/metabolismo , Gonadotropina Coriônica/farmacologia , Equidae , Feminino , Hormônio Foliculoestimulante/administração & dosagem , Hormônio Foliculoestimulante/metabolismo , Hormônio Luteinizante/administração & dosagem , Hormônio Luteinizante/metabolismo , Hormônio Luteinizante/farmacologia , Masculino , Radioimunoensaio , Chuva , Fatores de Tempo , Tempo (Meteorologia)
4.
J Appl Microbiol ; 125(3): 853-866, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29719942

RESUMO

AIMS: The aim of the study was to survey rhizobial biogeography and to inoculate soybean with selected rhizobia in China to enhance symbiotic nitrogen fixation (SNF). METHODS AND RESULTS: Biogeography, genetic diversity and phylogeny of soybean rhizobia were surveyed. Inocula were prepared and applied to soybean. Results showed that Bradyrhizobium elkanii and Ensifer fredii were widely distributed in acid and alkaline soils respectively. Available iron was detected as the first determinant for distribution of the two rhizobia and the soybean varieties did not greatly affect the rhizobial compatibility. Geographical latitude and precipitation in June were the main geographical and climatic factors affecting the rhizobial distribution. Inoculation with selected rhizobia increased the nodule number, fresh weight, occupation ratio, seed protein content and soybean yields. CONCLUSIONS: Selection and application of effective soybean rhizobia across China according to biogeography were clarified to promote the SNF, thereby improving soybean yield. SIGNIFICANCE AND IMPACT OF THE STUDY: Rhizobial diversity and biogeography were evaluated systematically in six sites across China. Available iron and soil pH are found to be the most important determinants for the distribution of soybean rhizobia. Inoculation to soybean enhances SNF, positively correlating to the increase in soybean yield and seed protein content.


Assuntos
Glycine max/microbiologia , Rizoma/microbiologia , Microbiologia do Solo , Bradyrhizobium/genética , China , Variação Genética
5.
Environ Sci Nano ; 3(5): 1215-1221, 2016 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-28133538

RESUMO

Iron-based nanoparticles form the basis for a host of sustainable alternative technologies based on this earth-abundant, low-toxicity element that can adopt a variety of oxidation states, crystal phases, and functions. Control of size, shape, and phase stability is a challenge for many nano-iron-based technologies, especially those involving Fe0 that is susceptible to oxidation under ambient conditions. This article presents a continuous method for hybridizing Fe-based nanoparticles with carbon in the form of graphene-encapsulated Fe-based particles with core-shell symmetry that allows flexible control of iron particle size, shape, and phase stability. The method uses FeOOH nanorods and graphene oxide as precursors, and subjects them to an aerosol-phase microdroplet drying and annealing process to yield a range of Fe/C nanohybrids whose structure can be controlled through adjustment of aerosol process temperature and post-synthesis thermal treatment conditions. We demonstrate that FeOOH nanorods can be successfully encapsulated in graphene, and transform during annealing into encapsulated Fe3O4 or Fe0 nanoparticles by reductive fragmentation, where the graphene nanosack acts as a carbothermic reductant. The hybrids are characterized by vibrating sample magnetometry and Cr(VI) reduction rates in aqueous media. The Fe0-graphene hybrids show high activity, good stability, and good recyclability in aqueous Cr(VI) removal due to the effect of graphene encapsulation. The present work suggests this rapid and continuous synthesis method can produce stable Fe-based materials, and can be extended to other metal systems, where graphene encapsulation can induce in situ reduction of metal oxide precursors into zero-valent metal-graphene hybrids.

6.
Transfus Med ; 25(3): 163-9, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26033335

RESUMO

OBJECTIVES: To analyse anti-D alloimmunisation in pregnant women with D-elute (DEL) phenotype in China, for developing a predictive model to evaluate whether a person with the DEL phenotype can receive RhD-positive blood. BACKGROUND: Alloanti-D acquired by pregnancy or transfusion is one of the major causes of both haemolytic disease among newborns and haemolytic transfusion reactions. To date, there is little data available about the antigenic properties and immunogenicity of extremely weak D variants known as DEL. METHODS: RHD genotyping and D epitope mapping were performed using gene sequencing and comprehensive immunohaematological methods, respectively. DEL pregnant women carrying an RhD-positive fetus were tested for the presence of alloanti-D. RESULTS: A total of 130 of 142 (91·5%) pregnant women with a DEL phenotype were confirmed to carry the RHD (K409K) allele. Among 12 DEL women who appeared to have RHD-CE-D hybrid alleles, there were 1 RHD-CE (4-7)-D, 7 RHD-CE(4-9)-D, and 4 RHD-CE (2-5)-D alleles. Alloanti-D antibodies were detected in 6 of 142 DEL women, and all the six women had the partial DEL phenotype. CONCLUSION: The data indicate that partial DEL women appear at risk of alloimmunization to the D antigen. RhD immune globulin prophylaxis is necessary for partial DEL women. Partial DEL patients should receive only RhD-negative RBCs, whereas DEL patients with complete expression of antigen can safely receive RhD-positive RBCs.


Assuntos
Alelos , Transfusão Feto-Materna/genética , Frequência do Gene , Isoimunização Rh/genética , Sistema do Grupo Sanguíneo Rh-Hr/genética , Adolescente , Adulto , Mapeamento de Epitopos , Feminino , Transfusão Feto-Materna/imunologia , Técnicas de Genotipagem , Humanos , Masculino , Pessoa de Meia-Idade , Gravidez , Isoimunização Rh/imunologia , Sistema do Grupo Sanguíneo Rh-Hr/imunologia , Imunoglobulina rho(D)/genética , Imunoglobulina rho(D)/imunologia
7.
Genet Mol Res ; 14(2): 4005-14, 2015 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-25966172

RESUMO

Casein kinase 2 interacting protein 1 (CKIP1) is a specific interacting protein of the casein kinase 2 (CK2) α subunit, and, by binding CK2 and other proteins, functions as an adaptor to regulate a series of cellular functions. Previous studies suggested that CKIP1 might play an important role in regulating oncogenic activities. However, few studies examining the function of CKIP1 in cancer cells have been performed. The present study aimed to investigate the role of CKIP1 in lung cancer. CKIP1 mRNA expression was detected in 5 human lung cancer cell lines (H-125, H1299, LTEP-A-2, SPC-A-1, and NCL-H446) by semi-quantitative RT-PCR, and in 10 noncancerous lung tissues and 30 non-small lung cancer tissues by real-time quantitative PCR. A lentivirus-mediated small interfering RNA (siRNA) was used to knock down CKIP1 expression in the H1299 cell line. To elucidate the impact of CKIP1 downregulation on H1299 cells, cell proliferation, DNA synthesis, and cell cycle distribution and apoptosis were measured by high content screening assay, BrdU incorporation, and flow cytometric analyses, respectively. CKIP1 mRNA was highly expressed both in H1299 cells and lung cancer tissues. We found that downregulation of CKIP1 resulted in suppression of proliferation and colony-forming ability of H1299 cells, and led to S phase cell cycle arrest and G2 phase promotion, as well as a significant enhancement of H1299 cell apoptosis. Our study indicated that high expression levels of CKIP1 were associated with the development of lung cancer, and that CKIP1 knockdown may block tumor cell growth mainly by promoting cell apoptosis.


Assuntos
Apoptose , Carcinoma Pulmonar de Células não Pequenas/genética , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Peptídeos e Proteínas de Sinalização Intracelular/genética , Neoplasias Pulmonares/genética , Ciclo Celular , Pontos de Checagem do Ciclo Celular , Linhagem Celular Tumoral , Regulação para Baixo , Humanos , Interferência de RNA , RNA Mensageiro/genética , RNA Interferente Pequeno/genética
8.
Eur J Vasc Endovasc Surg ; 45(5): 502-8, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23481411

RESUMO

OBJECTIVE: Spontaneous isolated dissection of the superior mesenteric artery (SIDSMA) is extremely rare. Various treatment options are currently available, including conservative treatment, endovascular stenting (ES) and surgical repair. Herein, we present our experience in the treatment of symptomatic SIDSMA. METHODS: A retrospective study was conducted on 17 consecutive patients with symptomatic SIDSMA from May 2002 to May 2012. Conservative treatment consisted of strict blood-pressure control, bowel rest, nasogastric suction, intravenous fluid therapy and nutritional support as required; fasting was released on resolution of abdominal pain, and fluid food was given first; then, diet was resumed after complete resolution of abdominal pain. The decision to intervene was based on patient symptoms and signs, as well as the morphological characteristics of SMA dissection on computed tomography (CT) angiography. Self-expandable stents were placed via the common femoral artery approach. ES was indicated in patients with severe compression of the true lumen or dissecting aneurysm likely to rupture. RESULTS: All patients had acute-onset abdominal pain. Treatment included conservative treatment with the use of anticoagulation in five and without in nine patients, respectively. Three patients with severe compression of the true lumen or large dissecting aneurysm underwent ES as a primary treatment. ES was performed in two patients in whom initial conservative treatment failed. Patients who underwent ES were maintained on anti-platelet therapy for 3 months postoperatively. The median follow-up time was 24 months (range, 2-72 months). No complications were associated with the SIDSMA or ES. The patency of stents was demonstrated on follow-up CT scans up to 8.5 months (range, 4-38 months). CONCLUSIONS: Conservative treatment without anticoagulation can be applied successfully to the patients with symptomatic SIDSMA. Our strategy of restricting ES for these patients who have compression of the true lumen or dissecting aneurysm likely to rupture (and for those with failed conservative treatment) was successful.


Assuntos
Dissecção Aórtica/terapia , Artéria Mesentérica Superior , Abdome Agudo/etiologia , Idoso , Dissecção Aórtica/complicações , Dissecção Aórtica/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
9.
J Exp Bot ; 64(6): 1485-96, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23378379

RESUMO

The beneficial effects of elevated CO2 on plants are expected to be compromised by the negative effects posed by other global changes. However, little is known about ozone (O3)-induced modulation of elevated CO2 response in plants with differential sensitivity to O3. An old (Triticum aestivum cv. Beijing 6, O3 tolerant) and a modern (T. aestivum cv. Zhongmai 9, O3 sensitive) winter wheat cultivar were exposed to elevated CO2 (714 ppm) and/or O3 (72 ppb, for 7h d(-1)) in open-topped chambers for 21 d. Plant responses to treatments were assessed by visible leaf symptoms, simultaneous measurements of gas exchange and chlorophyll a fluorescence, in vivo biochemical properties, and growth. It was found that elevated CO2 resulted in higher growth stimulation in the modern cultivar attributed to a higher energy capture and electron transport rate compared with the old cultivar. Exposure to O3 caused a greater growth reduction in the modern cultivar due to higher O3 uptake and a greater loss of photosystem II efficiency (mature leaf) and mesophyll cell activity (young leaf) than in the old cultivar. Elevated CO2 completely protected both cultivars against the deleterious effects of O3 under elevated CO2 and O3. The modern cultivar showed a greater relative loss of elevated CO2-induced growth stimulation due to higher O3 uptake and greater O3-induced photoinhibition than the old cultivar at elevated CO2 and O3. Our findings suggest that the elevated CO2-induced growth stimulation in the modern cultivar attributed to higher energy capture and electron transport rate can be compromised by its higher O3 uptake and greater O3-induced photoinhibition under elevated CO2 and O3 exposure.


Assuntos
Dióxido de Carbono/metabolismo , Ozônio/metabolismo , Fotossíntese , Triticum/crescimento & desenvolvimento , Clorofila/análise , Clorofila/metabolismo , Clorofila A , Transporte de Elétrons , Metabolismo Energético , Células do Mesofilo/metabolismo , Processos Fotoquímicos , Complexo de Proteína do Fotossistema II/metabolismo , Doenças das Plantas , Folhas de Planta/metabolismo , Especificidade da Espécie , Fatores de Tempo
10.
J Exp Bot ; 62(12): 4153-62, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21527624

RESUMO

Recent reports challenge the widely accepted idea that drought may offer protection against ozone (O(3)) damage in plants. However, little is known about the impact of drought on the magnitude of O(3) tolerance in winter wheat species. Two winter wheat species with contrasting sensitivity to O(3) (O(3) tolerant, primitive wheat, T. turgidum ssp. durum; O(3) sensitive, modern wheat, T. aestivum L. cv. Xiaoyan 22) were exposed to O(3) (83ppb O(3), 7h d(-1)) and/or drought (42% soil water capacity) from flowering to grain maturity to assess drought-induced modulation of O(3) tolerance. Plant responses to stress treatments were assessed by determining in vivo biochemical parameters, gas exchange, chlorophyll a fluorescence, and grain yield. The primitive wheat demonstrated higher O(3) tolerance than the modern species, with the latter exhibiting higher drought tolerance than the former. This suggested that there was no cross-tolerance of the two stresses when applied separately in these species/cultivars of winter wheat. The primitive wheat lost O(3) tolerance, while the modern species showed improved tolerance to O(3) under combined drought and O(3) exposure. This indicated the existence of differential behaviour of the two wheat species between a single stress and the combination of the two stresses. The observed O(3) tolerance in the two wheat species was related to their magnitude of drought tolerance under a combination of drought and O(3) exposure. The results clearly demonstrate that O(3) tolerance of a drought-sensitive winter wheat species can be completely lost under combined drought and O(3) exposure.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Secas , Ozônio/farmacologia , Estações do Ano , Triticum/efeitos dos fármacos , Triticum/fisiologia , Análise de Variância , Transporte de Elétrons/efeitos dos fármacos , Fótons , Fotossíntese/efeitos dos fármacos , Complexo de Proteína do Fotossistema II/metabolismo , Estômatos de Plantas/efeitos dos fármacos , Estômatos de Plantas/fisiologia , Triticum/crescimento & desenvolvimento
11.
J Exp Bot ; 59(4): 951-63, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18310606

RESUMO

Modern wheat (Triticum aestivum L.) is one of the most ozone (O(3))-sensitive crops. However, little is known about its genetic background of O(3) sensitivity, which is fundamental for breeding O(3)-resistant cultivars. Wild and cultivated species of winter wheat including donors of the A, B and D genomes of T. aestivum were exposed to 100 ppb O(3) or charcoal-filtered air in open top chambers for 21 d. Responses to O(3) were assessed by visible O(3) injury, gas exchange, chlorophyll fluorescence, relative growth rate, and biomass accumulation. Ozone significantly decreased light-saturated net photosynthetic rate (-37%) and instantaneous transpiration efficiency (-42%), but increased stomatal conductance (+11%) and intercellular CO(2) concentration (+11%). Elevated O(3) depressed ground fluorescence (-8%), maximum fluorescence (-26%), variable fluorescence (-31%), and maximum photochemical efficiency (-7%). Ozone also decreased relative growth rate and the allometric coefficient, which finally reduced total biomass accumulation (-54%), but to a greater extent in roots (-77%) than in the shoot (-44%). Winter wheat exhibited significant interspecies variation in the impacts of elevated O(3) on photosynthesis and growth. Primitive cultivated wheat demonstrated the highest relative O(3) tolerance followed by modern wheat and wild wheat showed the lowest. Among the genome donors of modern wheat, Aegilops tauschii (DD) behaved as the most O(3)-sensitive followed by T. monococcum (AA) and Triticum turgidum ssp. durum (AABB) appeared to be the most O(3)-tolerant. It was concluded that the higher O(3) sensitivity of modern wheat was attributed to the increased O(3) sensitivity of Aegilops tauschii (DD), but not to Triticum turgidum ssp. durum (AABB) during speciation.


Assuntos
Ozônio/toxicidade , Triticum/efeitos dos fármacos , Triticum/genética , Clorofila/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Transpiração Vegetal/efeitos dos fármacos , Especificidade da Espécie
12.
Ann Bot ; 96(5): 925-30, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16103036

RESUMO

BACKGROUND AND AIMS: New maize (Zea mays) hybrids outperformed old ones even at reduced N rates. Understanding the mechanisms of the differences in performance between newer and older hybrids under N deficiency could provide avenues for breeding maize cultivars with large yield under N deficiency, and reduce environmental pollution caused by N fertilizers. METHODS: N deficiency effects on grain weight, plant weight, harvest index, leaf area and photosynthetic traits were studied in the field for six maize hybrids released during the past 50 years to compare their tolerance and to explore their physiological mechanisms. KEY RESULTS: N deficiency decreased grain yield and plant weight in all hybrids, especially in the older hybrids. However, there was no significant difference in harvest index, rate of light-saturated photosynthesis (Psat) 20 d before flowering, leaf area or plant weight at flowering between the N-deficient and control plants of all hybrids. Dry matter production after flowering of the N-deficient plants was significantly lower than that of the control plants in all hybrids, especially in the older hybrids, and was mostly due to differences in the rate of decrease in photosynthetic capacity during this stage. The lower Psat of the older hybrids was not due to stomatal limitation, as there was no significant difference in stomatal conductance (gs) and intercellular CO2 concentration (Ci) between the hybrids. N deficiency accelerated senescence, i.e. decreased chlorophyll and soluble protein contents, after anthesis more for the earlier released hybrids than for the later ones. N deficiency decreased phosphoenolpyruvate carboxylase (PEPCase) activity significantly more in older hybrids than newer hybrids, and affected the maximal efficiency of PSII photochemistry (Fv/Fm) only in the old hybrids and at the late stage. CONCLUSIONS: Compared with older (earlier released) hybrids, newer (later released) hybrids maintained greater plant and grain weight under N deficiency because their photosynthetic capacity decreased more slowly after anthesis, associated with smaller non-stomatal limitations due to maintenance of PEPCase activity, and chlorophyll and soluble protein content.


Assuntos
Hibridização Genética , Nitrogênio/deficiência , Fotossíntese/fisiologia , Zea mays/metabolismo , Dióxido de Carbono/metabolismo , Clorofila/metabolismo , Cruzamentos Genéticos , Flores/fisiologia , Luz , Nitrogênio/metabolismo , Proteínas de Plantas/metabolismo , Fatores de Tempo , Zea mays/genética
13.
J Plant Res ; 116(5): 347-54, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12898392

RESUMO

Photosynthetic rates in different development stages were carefully investigated in 18 cultivars of winter wheat released in the period between 1945 and 1995 in the area of Beijing, China. During this period, the recorded grain yield has increased eightfold. However, when those cultivars were planted and managed in the same environment, the difference was reduced to only 36%, indicating that agronomic practices are the most important factors for grain yield. Agronomic features have changed greatly in the past 50 years, through increasing the harvest index (R2 = 0.89, P < 0.05), shortening plant height (R2 = 0.77, P < 0.05) and slightly increasing flag leaf areas (R2 = 0.45, P < 0.05), which is mostly in agreement with many other researchers. In contrast to many reports, however, this study found a genetic increase in the rate of photosynthesis per unit leaf area. From the mid-stem elongation to soft dough stages, the average photosynthetic rates at saturated photosynthetic photon flux density (P(sat)) increased by 44%. In the process, the stomatal conductance (g(s)) also increased by 122%. Grain yield was positively related to the mean values of P(sat) (R2 = 0.61, P < 0.01) and g(s) (R2 = 0.67, P < 0.01) in the six development stages. Our experiment may suggest that increase in grain yield was associated with the elevation of leaf photosynthetic rate and stomatal conductance over the past 50 years.


Assuntos
Fotossíntese , Triticum/fisiologia , Triticum/crescimento & desenvolvimento
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