Temporal and spatial progress of the diseases caused by the crinivirus tomato chlorosis virus and the begomovirus tomato severe rugose virus in tomatoes in Brazil     

M. A. Macedo  A. K. Inoue-Nagata  T. N. Z. Silva  D. M. S. Freitas  J. A. M. Rezende  J. C. Barbosa  M. Michereff-Filho  A. R. Nascimento  A. L. Lourenção  A. Bergamin Filho 《Plant pathology》2019,68(1):72-84

Efficient management of whitefly-borne diseases remains a challenge due to the lack of a comprehensive understanding of their epidemiology, particularly of the diseases tomato golden mosaic and tomato yellowing. Here, by monitoring 16 plots in four commercial fields, the temporal and spatial distribution of these two diseases were studied in tomato fields in Brazil. In the experimental plots these diseases were caused by tomato severe rugose virus (ToSRV) and tomato chlorosis virus (ToCV), respectively. The incidence of each virus was similar in the plots within a field but varied greatly among fields. Plants with symptoms for both diseases were randomly distributed in three of four spatial analyses. The curves representing the progress of both diseases were similar and contained small fluctuations, indicating that the spread of both viruses was similar under field conditions. In transmission experiments of ToSRV and ToCV by Bemisia tabaci MEAM1 (former biotype B), these viruses had a similar transmission rate in single or mixed infections. It was then shown that primary and secondary spread of ToCV were not efficiently controlled by insecticide applications. Finally, in a typical monomolecular model of disease progress, simulation of the primary dissemination of ToSRV and ToCV showed that infected plants were predominantly randomly distributed. It is concluded that, although the manner of vector transmission differs between ToSRV (persistent) and ToCV (semipersistent), the main dispersal mechanisms are most probably similar for these two diseases: primary spread is the predominant mechanism, and epidemics of these diseases have been caused by several influxes of viruliferous whiteflies.  相似文献   

Influence of temperature,humidity duration and growth stage on the infection and mycotoxin production by Fusarium langsethiae and Fusarium poae in oats     

T. Schöneberg  K. Kibler  F. E. Wettstein  T. D. Bucheli  H. R. Forrer  T. Musa  F. Mascher  M. Bertossa  B. Keller  S. Vogelgsang 《Plant pathology》2019,68(1):173-184

High occurrence of Fusarium poae (FP) and Fusarium langsethiae (FL) and their mycotoxins nivalenol (NIV) and T-2/HT-2 have been observed in Swiss oats. Early prediction of mycotoxin levels is important for farmers and the cereal industry to minimize the risk of contaminated food and feed. Therefore, climate chamber experiments were conducted to investigate the influence of different temperatures (10, 15, 20 °C) and durations (4, 8, 12 h) at 99% relative humidity (RH) on the infection of oats with FP and FL. In addition, to discover the most susceptible period of oats, artificial FL inoculations were conducted at different growth stages. Field experiments were performed to observe the dispersal of these fungal species within the field and to investigate the weather conditions that influence the dispersal. The climate chamber experiments revealed higher contamination with NIV and T-2/HT-2 in the 10 °C treatments and with a prolonged humidity duration of 12 h 99% RH. Inoculations of oat plants at early (DC 61) and mid (DC 65) anthesis, led to higher FL infection and T-2/HT-2 accumulation in the grains compared with treatments at earlier growth stages, which might be due to an increased susceptibility during anthesis. No indication for spore dispersal was observed in the field experiments. The results obtained, together with the cropping factors that influence infection and mycotoxin production, could be used as a first step in developing forecasting models to predict the contamination of oats with the mycotoxins NIV and T-2/HT-2.  相似文献   

<Emphasis Type="Italic">Lupinus albus</Emphasis> Conglutin Gamma Modifies the Gene Expressions of Enzymes Involved in Glucose Hepatic Production <Emphasis Type="Italic">In Vivo</Emphasis>     

Ana E. González-Santiago  Belinda Vargas-Guerrero  Pedro M. García-López  Alma L. Martínez-Ayala  José A. Domínguez-Rosales  Carmen M. Gurrola-Díaz 《Plant foods for human nutrition (Dordrecht, Netherlands)》2017,72(2):134-140

Lupinus albus seeds contain conglutin gamma (Cγ) protein, which exerts a hypoglycemic effect and positively modifies proteins involved in glucose homeostasis. Cγ could potentially be used to manage patients with impaired glucose metabolism, but there remains a need to evaluate its effects on hepatic glucose production. The present study aimed to analyze G6pc, Fbp1, and Pck1 gene expressions in two experimental animal models of impaired glucose metabolism. We also evaluated hepatic and renal tissue integrity following Cγ treatment. To generate an insulin resistance model, male Wistar rats were provided 30% sucrose solution ad libitum for 20 weeks. To generate a type 2 diabetes model (STZ), five-day-old rats were intraperitoneally injected with streptozotocin (150 mg/kg). Each animal model was randomized into three subgroups that received the following oral treatments daily for one week: 0.9% w/v NaCl (vehicle; IR-Ctrl and STZ-Ctrl); metformin 300 mg/kg (IR-Met and STZ-Met); and Cγ 150 mg/kg (IR-Cγ and STZ-Cγ). Biochemical parameters were assessed pre- and post-treatment using colorimetric or enzymatic methods. We also performed histological analysis of hepatic and renal tissue. G6pc, Fbp1, and Pck1 gene expressions were quantified using real-time PCR. No histological changes were observed in any group. Post-treatment G6pc gene expression was decreased in the IR-Cγ and STZ-Cγ groups. Post-treatment Fbp1 and Pck1 gene expressions were reduced in the IR-Cγ group but increased in STZ-Cγ animals. Overall, these findings suggest that Cγ is involved in reducing hepatic glucose production, mainly through G6pc inhibition in impaired glucose metabolism disorders.  相似文献   

Mapping QTLs using a novel source of salinity tolerance from Hasawi and their interaction with environments in rice     

M. Akhlasur Rahman  Isaac Kofi Bimpong  J. B. Bizimana  Evangeline D. Pascual  Marydee Arceta  B. P. Mallikarjuna Swamy  Faty Diaw  M. Sazzadur Rahman  R. K. Singh 《Rice》2017,10(1):47

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Phenological and physiological evaluation of first and second cropping periods of sorghum and maize crops     

Maria Antonia Machado Barbosa  Kacilda Naomi Kuki  Pedro Santos Peno Bengala  Emilly dos Santos Pereira  Angélica Fátima de Barros  Sebastián Giraldo Montoya  Leonardo Duarte Pimentel 《Journal of Agronomy and Crop Science》2020,206(2):263-276

Environmental conditions influence phenology and physiological processes of plants. It is common for maize and sorghum to be sown at two different periods: the first cropping (spring/summer) and the second cropping (autumn/winter). The phenological cycle of these crops varies greatly according to the planting season, and it is necessary to characterize the growth and development to facilitate the selection of the species best adapted to the environment. The aim of this study was to characterize phenological phases and physiological parameters in sorghum and maize plants as a function of environmental conditions from the first cropping and second cropping periods. Two parallel experiments were conducted with both crops. The phenological characterization was based on growth analyses (plant height, leaf area and photoassimilate partitioning) and gas exchange evaluations (net assimilation rate, stomatal conductance, transpiration and water-use efficiency). It was found that the vegetative stage (VS) for sorghum and maize plants was 7 and 21 days, respectively, longer when cultivated during the second cropping. In the first cropping, the plants were taller than in the second cropping, regardless of the crop. The stomatal conductance of sorghum plants fluctuated in the second cropping during the development period, while maize plants showed decreasing linear behaviour. Water-use efficiency in sorghum plants was higher during the second cropping compared with the first cropping. In maize plants, in the second cropping, the water-use efficiency showed a slight variation in relation to the first cropping. It was concluded that the environmental conditions as degree-days, temperature, photoperiod and pluvial precipitation influence the phenology and physiology of both crops during the first and the second cropping periods, specifically cycle duration, plant height, leaf area, net assimilation rate, stomatal conductance and water-use efficiency, indicating that both crops respond differentially to environmental changes during the growing season.  相似文献   

Pigeonpea improvement: An amalgam of breeding and genomic research     

Sameer Kumar Chanda Venkata  Ganga Rao Nadigatla Veera Prabha Rama  Rachit K. Saxena  Kulbhushan Saxena  Hari D. Upadhyaya  Moses Siambi  Said N. Silim  Kothapally Narasimha Reddy  Anupama J. Hingane  Mamta Sharma  Shivali Sharma  Stephen Dominic Lyimo  Rose Ubwe  Meshack Makenge  Kananji Gad  Paul Kiprotich Kimurto  Manuel Amane  Kennedy Kanenga  Yuventino Obong  Emanuel Monyo  Chris Ojiewo  Nagesh Kumar Mallela Venkata  Jaganmohan Polineni Rao  Prashanthi Lakkireddy  Sudhakar Chourat  Indraprakash Singh  Sobhan Sajja  Shruthi Hirikara Beliappa  Rajeev K. Varshney 《Plant Breeding》2019,138(4):445-454

In the past five decades, constant research has been directed towards yield improvement in pigeonpea resulting in the deployment of several commercially acceptable cultivars in India. Though, the genesis of hybrid technology, the biggest breakthrough, enigma of stagnant productivity still remains unsolved. To sort this productivity disparity, genomic research along with conventional breeding was successfully initiated at ICRISAT. It endowed ample genomic resource providing insight in the pigeonpea genome combating production constraints in a precise and speedy manner. The availability of the draft genome sequence with a large‐scale marker resource, oriented the research towards trait mapping for flowering time, determinacy, fertility restoration, yield attributing traits and photo‐insensitivity. Defined core and mini‐core collection, still eased the pigeonpea breeding being accessible for existing genetic diversity and developing stress resistance. Modern genomic tools like next‐generation sequencing, genome‐wide selection helping in the appraisal of selection efficiency is leading towards next‐generation breeding, an awaited milestone in pigeonpea genetic enhancement. This paper emphasizes the ongoing genetic improvement in pigeonpea with an amalgam of conventional breeding as well as genomic research.  相似文献   

Assessing seed desiccation responses of native trees in the Caribbean     

Mattana  Efisio  Peguero  Brígido  Di Sacco  Alice  Agramonte  Wilvin  Encarnación Castillo  Wilkin Rafael  Jiménez  Francisco  Clase  Teodoro  Pritchard  Hugh W.  Gómez-Barreiro  Pablo  Castillo-Lorenzo  Elena  Terrero Encarnación  Marianny  Way  Michael J.  García  Ricardo  Ulian  Tiziana 《New Forests》2020,51(4):705-721

New Forests - Native trees from the Caribbean were tested for seed desiccation responses, by adapting the “100-seed test” protocol. Ninety-seven seed lots of 91 species were collected...  相似文献   

Prediction of Genetic Gain in Sweet Corn using Selection Indexes     

da Silva  Isadora Gonçalves  Castoldi  Renata  de Oliveira Charlo  Hamilton César  de Souza Miranda  Mateus  Nunes  Thaíssa Dias Cardoso  Costa  Luciene Lacerda  Lemes  Ernane Miranda 《Journal of Crop Science and Biotechnology》2020,23(2):191-196

Journal of Crop Science and Biotechnology - The cultivation of sweet corn is expanding in Brazil, but there are serious constraints about the availability of commercial cultivars. The selection of...  相似文献   

Climate change will affect the ability of forest management to reduce gaps between current and presettlement forest composition in southeastern Canada     

Boulanger  Yan  Arseneault  Dominique  Boucher  Yan  Gauthier  Sylvie  Cyr  Dominic  Taylor  Anthony R.  Price  David T.  Dupuis  Sébastien 《Landscape Ecology》2019,34(1):159-174

Landscape Ecology - Forest landscapes at the boreal–temperate ecotone have been extensively altered. Reducing the gap between current and presettlement forest conditions through...  相似文献   

The role of ear environment in postharvest susceptibility of maize to toxigenic Aspergillus flavus     

Samuel K. Mutiga  Nelson Chepkwony  Owens A. Hoekenga  Sherry A. Flint‐Garcia  Rebecca J. Nelson 《Plant Breeding》2019,138(1):38-50

A kernel screening assay (KSA) was used to assess the genetic and environmental effects on the vulnerability of maize to aflatoxin accumulation. Kernels of 26 inbred lines that had been grown in seven environments, and 190 lines of the Intermated B73xMo17 (IBM) population grown in one location in the United States, were inoculated with a toxigenic strain of A. flavus and incubated in the dark at 30°C for 6 days. Percent kernel colonization (PKC), sporulation and aflatoxin were influenced by the maize genotypes (G), the location (“ear environment” or E) and the GxE interactions. Overall, low broad‐sense heritabilities were observed for PKC, sporulation and aflatoxin. PKC was significantly correlated with sporulation in all environments. Aflatoxin was positively correlated with colonization for two and with sporulation for all ear environments. Higher grain sulphur or magnesium in IBM was associated with less colonization or aflatoxin. Postharvest susceptibility of maize to aflatoxin is thus influenced by factors that are modulated by the ear environment. In a KSA, sporulation could be a proxy test for aflatoxin accumulation.  相似文献