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101.
Rice (Oryza sativa L.) is one of the most sensitive crops to drought, salt and cold stresses, particularly at post germination stage. The effects of these stresses on some physiological responses of two (a salt tolerant and a sensitive) rice cultivars ‘FL478’ and ‘IR29’ were investigated in this study. Two-day seedlings were transferred to MS media complemented with iso-osmotic concentrations of sodium chloride (NaCl; 0, 50, 100, and 150 mM) or mannitol (0, 100, 180, and 275 mM) at 25°C or four and 15°C for 10 days. Experiments were carried out based on completely randomized design, with at least three replicates. All three stresses decreased shoot growth, chlorophylls, carotenoids and root starch while increased shoot soluble sugars. The effect of exerted cold stress on growth, hydrogen peroxide (H2O2) and malonyldialdehyde levels, electrolyte leakage, chlorophylls and carotenoids contents was more than or comparable with drought, but greater than salinity. The results also indicated higher tolerance of ‘‘FL478’’ not only to salinity but also to drought compared to ‘‘IR29’’. Therefore, a mechanism for osmotic stress adjustment is probable in ‘‘FL478’’ in addition to low sodium (Na+) to potassium (K+) ratio in shoot tissues under salinity.  相似文献   
102.
The objective of this study was to estimate genetic parameters for reproductive traits in Shall sheep. Data included 1,316 records on reproductive performances of 395 Shall ewes from 41 sires and 136 dams which were collected from 2001 to 2007 in Shall breeding station in Qazvin province at the Northwest of Iran. Studied traits were litter size at birth (LSB), litter size at weaning (LSW), litter mean weight per lamb born (LMWLB), litter mean weight per lamb weaned (LMWLW), total litter weight at birth (TLWB), and total litter weight at weaning (TLWW). Test of significance to include fixed effects in the statistical model was performed using the general linear model procedure of SAS. The effects of lambing year and ewe age at lambing were significant (P?<?0.05). Genetic parameters were estimated using restricted maximum likelihood procedure, under repeatability animal models. Direct heritability estimates were 0.02, 0.01, 0.47, 0.40, 0.15, and 0.03 for LSB, LSW, LMWLB, LMWLW, TLWB, and TLWW, respectively, and corresponding repeatabilities were 0.02, 0.01, 0.73, 0.41, 0.27, and 0.03. Genetic correlation estimates between traits ranged from ?0.99 for LSW–LMWLW to 0.99 for LSB–TLWB, LSW–TLWB, and LSW–TLWW. Phenotypic correlations ranged from ?0.71 for LSB–LMWLW to 0.98 for LSB–TLWW and environmental correlations ranged from ?0.89 for LSB–LMWLW to 0.99 for LSB–TLWW. Results showed that the highest heritability estimates were for LMWLB and LMWLW suggesting that direct selection based on these traits could be effective. Also, strong positive genetic correlations of LMWLB and LMWLW with other traits may improve meat production efficiency in Shall sheep.  相似文献   
103.
A two-month trial was conducted to investigate the effects of pelleting rations with 70:30, 65:35, and 60:40 concentrate to high-quality roughage (alfalfa hay) ratios on hematological and biochemical parameters of ostriches. A total of 18 seven-month-old male ostrich chicks, initially weighing an average of 60–70 kg, were distributed into three different outdoor paddocks at a stocking density of six birds per paddock. In the morning, blood collection was made from the wing vein after about 12 h of fasting. All rations resulted in no significant change in hematological parameters. However, with increasing alfalfa inclusion rate, the heterophil/lymphocyte ratio tended to be lower (P?=?0.089); whereas the values of hemoglobin, packed cell volume (PCV), and mean corpuscular hemoglobin (MCH) tended to be higher (P values 0.069, 0.072 and 0.094, respectively). In terms of plasma biochemical parameters, increasing the ratio of concentrate to alfalfa hay in ostrich diets resulted in significant (P?<?0.05) depression in the values of glucose (up to 20.2 %), total cholesterol (up to 19.2 %), creatine kinase (up to 27.9 %), and aspartate aminotransferase (up to 29.9 %). Additionally, the 65:35 or 60:40 rations caused a decrease in low-density lipoprotein cholesterol level (27.9 and 42 %, respectively; P?=?0.008) compared to the 70:40 ration. Without exception, no rations affected the values of leukocyte subsets, total protein, albumin, globulin, uric acid, alanine aminotransferase, gamma glutamyl transferase, triglycerides, high-density lipoprotein cholesterol, and very low density lipoprotein. Based on our results, the concentrate to alfalfa ratio of 60:40 could be suggested as optimum ratio for good health conditions of juvenile ostriches.  相似文献   
104.

Genotype by environment interaction for production and fertility was studied by use of a reaction norm model. Milk recording data, comprising 927 929 records, were analysed to predict reaction norms for young bulls of the Nordic Red dairy breeds. Random regressions were estimated for each bull, regressing phenotypic values of daughters on herd environment. The phenotypic measures were 305 days kg protein production and days open in first lactation. The herd environment was defined as the herd-year average of protein production and days open, respectively. Heritability of protein production and days open and genetic correlation between the two traits were estimated as functions of the herd environment. The results showed that the genetic parameters change over environments, which are measured on a continuous scale across countries. Grouping of observations is avoided and thereby the problem of genetic connectedness between groups or countries may be avoided. Although significant genetic variation for the slope of the reaction norm was found, there was little reranking of sires, except between extreme environments. More appropriate models and methods need to be developed for further studies of genetic variation in reaction norms.  相似文献   
105.
Background: The secondary genetic changes other than the promyelocytic leukemia-retinoic acid receptor (PML-RARA) fusion gene may contribute to the acute promyelocytic leukemogenesis. Chromosomal alterations and mutation of FLT3 (FMS-like tyrosine kinase 3) tyrosine kinase receptor are the frequent genetic alterations in acute myeloid leukemia. However, the prognostic significance of FLT3 mutations in acute promyelocytic leukemia (APL) is not firmly established. Methods: In this study, the chromosomal abnormalities were analyzed by bone marrow cytogenetic in 45 APL patients and FLT3 internal tandem duplications (ITD) screening by fragment length analysis and FLT3 D835 mutation by melting curve analysis were screened in 23 APL samples. Results: Cytogenetic study showed 14.3% trisomy 8 and 17.1% chromosomal abnormalities other than t(15;17). About 13% of the patients had FLT3 ITD, and 26% had D835 point mutation. FLT3 ITD mutation was associated with higher white blood cell count at presentation and poor prognosis. Conclusion: The PML-RARA translocation alone may not be sufficient to induce leukemia. Therefore, we assume that FLT3 mutations and the other genetic and chromosomal alterations may cooperate with PML-RARA in the development of APL disease.Key Words: Chromosome aberrations, FMS-like tyrosine kinase 3, Acute promyelocytic leukemia  相似文献   
106.

Background

The aim of this study was to understand any association between differentiated thyroid carcinoma (DTC) and Ile3434Thr XRCC7 gene polymorphism (GenBank accession number: rs7830743). DTC is the most prevalent thyroid neoplasm, which includes papillary and follicular cell carcinoma. XRCC7 gene encodes a protein that functions in non-homologous end joining DNA repair pathway. Non-synonymous polymorphisms in this gene may alter DNA repair capacity of the cell and change the risk of developing cancers.

Methods

DTC patients (n = 173) and cancer free individuals (n = 204) were enrolled in a case-control study. The Ile3434Thr polymorphic alleles were discriminated by using amplification refractory mutation system-PCR method. The frequencies of this single nucleotide polymorphism in case and control groups were compared. Also, risk ratio for developing DTC in dichotomized genotypes was estimated by multivariate logistic regression analysis.

Results

Dichotomized genotypes into those with and without the 3434Thr allele showed that this allele was associated with DTC (OR [odd ratio]: 1.89, 95% confidence interval (CI) = 1.29-2.79, P<0.001). Also, TC genotype was significantly associated with increased risk of DTC (OR: 2.42, 95% CI = 1.55-3.81, P = 0.0001) in individuals carrying this genotype.

Conclusion

Allele 3434Thr in XRCC7 gene might be associated with differentiated thyroid cancer risk. Further studies with larger samples are needed to verify these initial findings. Key Words: DNA repair enzymes, Thyroid neoplasms, Genetic polymorphism  相似文献   
107.
This study investigated the effects of foliar application of normal and nano-sized zinc oxide on the response of sunflower cultivars to salinity. Treatments included five cultivars (‘Alstar’, ‘Olsion’, ‘Yourflor’, ‘Hysun36’ and ‘Hysun33’), two salinity levels [0 and 100 mM sodium chloride (NaCl)], and three levels of fertilizer application. Fertilizer treatments were the foliar application of normal and nano-sized zinc oxide (ZnO). Foliar application of ZnO in either forms increased leaf area, shoot dry weight, net carbon dioxide (CO2) assimilation rate (A), sub-stomatal CO2 concentration (Ci), chlorophyll content, Fv/Fm, and Zn content and decreased Na content in leaves. The extent of increase in chlorophyll content, Fv/Fm and shoot weight was greater as nano-sized ZnO was applied to the normal form. The results show that the nano-sized particles of ZnO compared to normal form has greater effect on biomass production of sunflower plants.  相似文献   
108.
The effect of soil applied zinc (Zn) sulfate and seed priming with Zn-glutamine [Zn(Gln)2], Zn-glycine [Zn(Gly)2], Zn-arginine [Zn(Arg)2], and Zn-histidine [Zn(His)2] on yield and grain nutritional quality of two bread (Triticum aestivum L. cvs. Back Cross and Kavir) and a durum wheat genotype (Triticum durum L. cv. Durum) was investigated. Seed priming with [Zn(Gly)2] and [Zn(Gln)2] increased grain yield of wheat over soil applied Zn-sulfate treatment by 46 and 14%, respectively. Seed priming with [Zn(Gln)2], [Zn(Arg)2], and [Zn(His)2] significantly increased grain protein content of wheat in comparison with control treatment. Seed priming with [Zn(Arg)2] and [Zn(His)2] resulted in higher Zn and Fe accumulation in wheat grain as compared with the other Zn treatments. Priming seeds with [Zn(Arg)2] reduced phytic acid to Zn molar ratio of wheat grain. Seed priming with [Zn(Arg)2] and [Zn(His)2] might be used as an alternative approach for soil application of Zn-sulfate to overcome Zn deficiency in calcareous soils.  相似文献   
109.
Soil salinity and arbuscular mycorrhizal fungi (AMF) influence the soil hydrophobicity. An experiment was performed to determine the effects of soil salinity and AMF species on soil water repellency (SWR) under wheat (Triticum aestivum L.) crop. Six AMF treatments, including four exotic species (Rhizophagus irregularis, Funneliformis mosseae and Claroideoglomus claroideum, a mix of three species), one mix native AMF species treatment and an AMF-free soil in combination with four salinity levels (1, 5, 10, and 15 dS m?1) were used. The soil repellency index (RI) increased with salinity increment ranging from 2.4 to 10.5. The mix of three exotic and native AMF treatments enhanced the RI significantly compared to AMF-free soil in all salinity levels with one exception for native treatment at 1 dS m?1. Among individual AMF species, the C. claroideum treatment at 10 dS m?1 increased the RI by 67% compared to AMF-free soil. The native AMF treatment was more efficient in root colonization, glomalin production and SWR development at 10 and 15 dS m?1, compared to exotic species. In addition to the net positive effect of salinity on SWR, the AMF influences on the RI were greatly dependent on salinity levels.  相似文献   
110.
Due to the variations in opacity and brightness of peroxide bleached pulp at Mazandaran Wood and Paper Industries Company (MWPI), empirical models were developed to predict chemimechanical pulp (CMP) brightness and opacity from peroxide bleaching conditions and to drive the optimum operating conditions. To overcome the inconsistency problem, a multi-variate regression analysis method was used for model building. The models were then validated using a new data set from the bleach plant at MWPI, assessing the models’ predictive ability and performance. The results show that there is a relationship between bleaching variables and such dependent variables as pulp brightness and opacity. In addition to the hydrogen peroxide charge and pulp initial brightness, the initial opacity had a significant reverse effect on the final CMP brightness. It was also found that the concentration of total Na+ in the CMP tower was the most important variable affecting the final pulp opacity. The validation results demonstrated that these models can be employed as useful tools for process optimization purposes.  相似文献   
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