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Mohammadi-Nejad G.,Shahid Bahonar University of Kerman | Singh R.K.,International Rice Research Institute | Arzani A.,Isfahan University of Technology | Rezaie A.M.,Isfahan University of Technology | And 2 more authors.
International Journal of Plant Production | Year: 2010

Salinity is considered as one of important physical factors influencing rice (Oryza sativa L.) production. Knowledge of salinity effects on rice seedling growth and yield components would improve management practices in fields and increase our understanding of salt tolerance mechanisms in rice. This study was designed to assess the role of Saltol QTL in regards to effects of salinity on plant growth and yield components of different genotypes of rice at different growth stages. A greenhouse study was conducted to evaluate the response of 30 rice genotypes to three levels of salt stresses (0, 60, 100 mM NaCl) at reproductive stage. The seedling stage response of these genotypes to salinity with electrical conductivity at 12 dSm-1 also investigated. Pollen viability, number of unfilled and filled grain and grain yield per plant were evaluated. The rice genotypes differed significantly for salt tolerance at seedling stage. The genotypes were also significantly varied for the traits measured at the reproductive stage. The interactions of genotypes x salinity treatments were significant for pollen viability, number of unfilled grain and grain yield. Grain yield reduction due to salinity was more sever for control to 60mM than for 60mM to 100mM. Pollen viability was found to be a robust criterion to screen the genotypes for salt tolerance at the reproductive stage. Pokkali cultivar possessing a major quantitative trait locus (QTL) for salt tolerance at seedling stage (Saltol) mapped on chromosome 1 was used as reference for haplotyping. Thirty rice genotypes divided into 16 different haplotypes based on Saltol QTL. RM8094 and RM10745 microsatelite markers found to be the most effective markers for discriminating the salinity tolerant genotypes. Source

Kagya-Agyemang J.K.,College of Agriculture Science and Education | Kagya-Agyemang J.K.,South China Agricultural University | Shendan S.,South China Agricultural University | Yinzuo B.,South China Agricultural University
International Journal of Poultry Science | Year: 2012

The hypothesis that serotonin (5-HT) and dopamine stimulate prolactin (PRL) release, either directly from the pituitary gland or by acting through Vasoactive Intestinal Peptide (VIP), was investigated by assessing the role of hypothalamic dopamine and 5-HT in the control of broodiness and PRL release in Cantonese native chicken breed called the Yuehuang hen. A second objective was to assess the involvement of hypothalamic VIP in the control of broodiness and PRL release by using dopamine and serotonin receptor antagonists respectively. In Experiment 1, two hundred laying hens from battery cages were transferred to floor pens with nest boxes to induce broodiness. Starting from the second day after the onset of broodiness, sixty hens were allotted into groups 1, 2 and 3 respectively, corresponding to chlorpromazine-treated (n = 20), cyproheptadine-treated (n = 20) and control (n = 20) groups. Blood samples were collected from the wing veins of hens in each group on days 2, 5, 9, 14 and 19 respectively after the onset of broodiness for radioimmunoassay of PRL and Luteinizing Hormone (LH). Results indicate that in the drug treated hens which terminated broodiness, the concentration of plasma PRL decreased significantly (p<0.01) while the concentration of plasma LH increased significantly (p<0.05) as compared to the control hens. The plasma PRL levels showed no significant (p>0.05) changes between the chlorpromazine and cyproheptadine treated hens. Within the chlorpromazine and cyproheptadine treated hens, there were significant (p<0.05) changes in plasma PRL levels between day 2 and days 5, 9, 14 and 19. The plasma PRL levels in the control hens showed no significant (p>0.05) changes throughout the blood sampling periods. Sixteen (80%) chlorpromazine treated hens terminated broodiness on an average of 4.6±0.8 days but four hens (20%) did not. However, thirteen (65%) cyproheptadine treated hens terminated broodiness on an average of 2.3±0.2 days while seven (35%) did not. In Experiment 2, sixty animals were used but their management and drug treatment for group 1 (n = 10) and group 2 (n = 10) were the same as described in Experiment 1. Group 3 (n = 10) served as the control. Eight hens each from groups 1, 2 and 3 were randomly selected for immunohistochemical studies. On day 7 after the onset of broodiness, hypothalamus from anaesthetized chlorpromazine and cyproheptadine treated hens as well as control hens were processed for immunohistochemical localization of VIP neurons in the hypothalamus of Yuehuang hens. Morphological observation showed a higher number of VIP neurons in the hypothalamus of the control hens. A few VIP neurons which were very faint were also found in the hypothalamus of the chlorpromazine and cyproheptadine treated hens. Results of these studies indicate a relationship between the functions of dopamine and 5-HT neurons in the hypothalamus and reproductive activities in domestic hens. They are consistent with the view that hypothalamic dopamine and 5-HT are regulators of PRL release and that using drugs which inhibit the functional activities of these neurotransmitters can inhibit PRL release to disrupt broodiness in hens to maintain egg production. The results also indicate a causal relationship between hypothalamic VIP and changes in PRL secretion associated with reproductive activities in domestic hens. This is consistent with the view that VIP might be an important hypothalamic PRL releasing neuropeptide and also indicate that VIP might be a physiological PRL regulatory hormone in domestic hens. © Asian Network for Scientific Information, 2012. Source

Li A.L.,College of Agriculture Science and Education
Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology | Year: 2011

To analyse the effect of 7 Lactobacillus species on proliferation and cytokine production of primary lymphocytes, and explored the effect on the Th1/Th2 cells balance. The mouse spleen cells were stimulated with active/heat-killed Lactobacillus strains at different species and concentrations. After be cultured with bacteria 60 hours, the proliferation of splenocytes were tested by MTT colorimetry, and IL-12, IFN-γ, IL-4, IL-10 and TGF-β were detected by ELISA. (1) Both alive and heat-killed Lactobacillus species could accelerate the proliferation of spleen cells in a dose-dependent manner (P<0.05), the immuneological activity of heat-killed L.fermentum and L.acidophilu were not inferior to the live strains, especially when treated at higher dose(10(7);CFU/mL, bacteria: cell ratio of 10:1). Furthermore, these two heat-killed bacterial strains suppressed IL-4, IL-10 and TGF-β production by stimulating IL-12 and IFN-γ production, and their IFN-γ/IL-4 value which represent the Th1/Th2 balance were higher than ConA control group significantly(P<0.05). The results indicate that Lactobacillus strains may differ in their respective ability to improve Th1/Th2 cells balance toward Th1 dominance via increasing the secretion ratio of IFN-γ/IL-4 (Th1/Th2) by splenocytes. Source

Edmunds B.A.,Oregon State University | Clark C.A.,Louisiana State University | Villordon A.Q.,Louisiana State University | Holmes G.J.,College of Agriculture Science and Education
Plant Disease | Year: 2015

Postharvest soft rots of sweetpotato caused by Rhizopus stolonifer (Rhizopus soft rot) and Dickeya dadantii (bacterial root rot) occur sporadically and can result in significant losses. A 3-year field study related preharvest conditions, including soil texture, chemistry, and fertility; air temperature; soil temperature and moisture; and various cultural practices (153 total variables), to postharvest susceptibility to both diseases in 75 sweetpotato fields in North Carolina and 63 sweetpotato fields in Louisiana. Storage roots were sampled from each field, cured, stored, and inoculated with each pathogen after 100 to 120 days in storage. Disease susceptibility was measured as incidence of diseased storage roots 10 days following inoculation. There was wide variation from field to field in incidence of both diseases (0 to 100% for Rhizopus soft rot and 5 to 95% for bacterial root rot) in both states in each year. Correlations between disease incidence and each of the preharvest variables revealed numerous significant correlations but the variables that correlated with disease incidence were different between North Carolina and Louisiana. Models for both diseases were built by first using forward stepwise regression to identify variables of interest, followed by a mixed-model analysis to produce a final reduced model. For North Carolina fields, postharvest Rhizopus soft rot susceptibility was described by the percentage of the soil cation exchange capacity occupied by calcium, amount of plant-available soil phosphorus, percent soil humic matter, mean air temperature, mean volumetric soil moisture at 40 cm in depth, and mean soil temperature at 2 cm in depth. Postharvest bacterial soft rot susceptibility was described by soil pH and the number of days of high soil temperature late in the season. For Louisiana fields, Rhizopus soft rot susceptibility was described by a complex of variables, including late-season air and soil temperature and late-season days of extreme soil moisture. For bacterial root rot, days of low air temperature and days of high soil temperature late in the season as well as days of low soil moisture best described variation. Although the influence of preharvest variables on postharvest susceptibility was profound for each disease, the complexity of factors involved and differences between the data for the two states makes development of a predictive system extremely difficult. © 2015 The American Phytopathological Society. Source

Liu Z.,College of Agriculture Science and Education
BioTechnology: An Indian Journal | Year: 2014

Baseball is a worldwide sports event; its high ornamental and competitiveness charm the people. And baseball game is also a game relies on apparatus, therefore bat some physical properties will have great effects on batters' abilities. This paper targeted market two kinds of textures (allwood and all aluminum) bats hitting effects, it makes deeply research from the two aspects. By deeply researching and analysis of bat hitting process and establishing physical model, it gets bat maximum delivery speed expression, therefore it gets aluminum bat maximum delivery speed is obviously larger than wood bat. Aluminum bat speed change curve is more smoothly than wood bat, which means hitting point position influences on hitting speed is not obvious so that cannot reflect batters' levels. By establishing bat elastic beam model, through analyzing, it gets wood bat and aluminum bat force status. © 2014 Trade Science Inc. - INDIA. Source

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