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101.
To determine the number of ejaculates which can be collected within a 20‐min period after the smallest number of days of sexual rest, and a good diluent to preserve semen for routine AI, five mature Black Bengal bucks were used in three experiments. In experiment 1, semen from the bucks were collected by using artificial vagina at homosexual mounts as many times as possible during 20 min. The ejaculate numbers 1, 3 and 4 (or 5 when the buck could produce it) were examined for important semen characteristics. The mean ejaculate volume, density, mass activity, sperm motility, sperm concentrations, total spermatozoa/ejaculate, proportion of spermatozoa with normal acrosome, midpiece and tail, and the proportion with normal head morphology varied between 267 and 342 µl, 4.1–4.5 (1–5 scale), 4.1–4.2 (1–5 scale), 77–79%, 4187 × 106–5064 × 106/ml, 1140 × 106–1746 × 106, 91–94% and 99%, respectively, depending on the collection number of the ejaculate. The difference between the ejaculates was significant only with respect to volume (p < 0.05). In experiment 2, semen was collected from the bucks successively during 20 min after 1, 2, 3 and 4 day intervals, and the first ejaculates were evaluated for the above‐mentioned semen characteristics. Semen collected after 2 or more day intervals had significantly higher volume, sperm concentration and total spermatozoa/ejaculate (p < 0.05). In experiment 3, pools of two to three ejaculates were diluted (1 : 5; semen : diluent) in splits with glucose‐citrate‐egg yolk (GCEY), Tris‐fructose‐egg yolk (TFEY) or skim milk (SM) and preserved at +4 to +7°C. Before chilling or after 0 (15 min chilling), 1, 2, 3 and 4 days of preservation, semen was evaluated for motility and proportion of normal spermatozoa with respect to acrosome, midpiece and tail. In data pooled across the bucks, the sperm motility was better in GCEY and TFEY than in SM, and the proportion of normal spermatozoa was higher in SM than in the others (p < 0.05). However, the differences in proportion of normal spermatozoa between diluents were not significant when the data were analysed separately within preservation periods. The sperm motility consistently dropped after 1 day of preservation (p < 0.01); the motility remained 50% or more up to 4 days in TFEY, 3 days in GCEY and only 2 days in SM. The proportion of spermatozoa with normal acrosome, midpiece and tail, which was generally quite high ( 90%), decreased after 3 days of preservation (p < 0.01). We conclude that Black Bengal bucks can be collected three times during 20 min, every 3 days, and that buck semen holds good motility and proportion of normal spermatozoa up to 3 days in GCEY or TFEY at 4 to 7°C.  相似文献   
102.
The Ma gene from Myrobalan plum is a TNL gene that confers a high-level resistance to all root-knot nematodes of major economic importance, including Meloidogyne incognita, M. javanica, M. arenaria, and M. enterolobii. The nematode behavior in the roots and the corresponding histological mechanisms of the Ma resistance to M. incognita in the resistant (R) accessions of the plum 'P.2175' and the interspecific hybrid P.2175×almond-peach '35', carrying the Ma1 allele (Ma1/ma), were characterized in comparison with the susceptible (S) accessions in the plum 'P.2032' and the interspecific hybrid P.2175×almond-peach '253' (ma/ma). Second-stage juveniles (J2s) were inoculated in micropropagated plantlets grown in soil substrate under controlled conditions at 25°C. Nematodes penetrated both R and S plants preferentially along the apical zone or close to the young lateral buds and moved via similar routes. Then they migrated into the cortex downward in the direction of the apex and turned up in the meristematic apical region to colonize the differentiating stele. In R accessions, motile J2s neither swelled nor developed into J3s, and initiation of feeding sites was never observed. This complete absence of gall symptoms is associated with cell necroses and corresponding hypersensitive-like reaction (HLR) phenotypes occurring either in the stele or in the meristematic apical region or in the cortex. Nematode attacks often disorganized the meristematic apical tissues of R accessions, which induced the development of subterminal lateral roots replacing primary terminal apices and, thus, provided an active resistance reaction to HLR damage.  相似文献   
103.

In order to study the effects of seed nitrogen content and biofertilizer priming on germination indices of wheat seeds under salinity stress, a factorial experiment based on a completely randomized design with four replications was conducted in 2009. Experimental factors consisted of: (1) the application of different nitrogen fertilizer rates (0, 55, 110 and 165 kg ha?1 N) on parent plants; (2) priming of achieved seeds by biofertilizers (Nitragin, Biophosphorus and distilled water); and (3) different levels of salinity produced by NaCl (0, ?0.4, ?0.8 and ?1.2 MPa). Germination percentage, germination rate, mean germination time, germination index, radicle and plumule length, radicle and plumule dry weight and radicle number per seedling were measured. Nitrogen application increased seed nitrogen content in parent plants. All germination indices decreased with increasing in salinity levels. Biofertilizer priming, especially Nitragin, had a positive effect on germination percentage, radicle number and radicle and plumule length in most salinity levels. The highest values for germination factors were related to achieved seeds from parent plants that were treated with 110 kg ha?1 N. Overall, application of middle levels of N fertilizer (55 and 110 kg ha?1 N) on parent plants combined with seed priming with Nitragin biofertilizer improved the germination indices of wheat under salinity stress.  相似文献   
104.
The distribution variability of soil electrical conductivity (EC), pH, clay, sand, CaCO3, organic carbon (OC) and available potassium (K) in the Naqade region was investigated using a geostatistical method and Geographical Information System (GIS) technique. Two hundred and eighty-two topsoil (0–30 cm) samples were randomly collected and analyzed. pH and clay followed a normal distribution, whereas sand EC, CaCO3, OC and K were log-transformed. The highest variation was observed for soil EC, and the lowest for soil pH. In the variography analysis, spherical, exponential and gaussian models were best fit on experimental semivariograms. The minimum effective spatial autocorrelation was 1500 m for OC and the maximum effective spatial autocorrelation was 4000 m for sand and K. Strong spatial correlations were noted with sand and CaCO3 (<25%), whereas values were moderate for clay, EC, OC and K (25–75%). Ordinary kriging was utilized for the interpolation of estimated variable determinations in unsampled sites. It was found that soil properties in this study area were strongly influenced by both environmental and natural factors. The results can be used as a source of information for the development and implementation of any further land management and soil and water conservation plans.  相似文献   
105.
The effect of various combination of macro (N, Mg, and K) and micronutrients (Fe and Zn) on yield, fruit quality, and tissue mineral concentrations of an important commercial table grape cultivar (Vitis vinifera cv. Bidaneh Qermez) was studied over three growing seasons of 1999–2001. Yield, fruit set, cluster weight, cluster number, berry size and quality attributes (soluble solid concentrations, pH, K-skin) were influenced by N, K, Mg, Fe, and Zn applications. Potassium application increased cluster number and weight, which resulted in a significant increase in the yield. Potassium influenced berry quality attributes more than other applied mineral elements. Yield was positively correlated to the soil total N at 30–60 cm depth. Nitrogen application increased growth of the main and lateral canes. Soil N did not correlate strongly with tissue N status.  相似文献   
106.
ABSTRACT

The effectiveness of nitrogen (N)+ zinc (Zn) soil and foliar fertilizer applications on growth, yield, and quality of apple (Malus domestic Borkh ‘Golden Delicious’) fruit was studied in the Zanjan province, Iran. There were eight treatments 1) control (no fertilizer), 2) soil applied N, 3) soil applied Zn, 4) soil applied N+Zn, 5) foliar applied N, 6) foliar applied Zn, 7) foliar applied N+Zn and 8) combined soil and foliar applied N+Zn. The N source was urea [CO(NH2)2, 46% N] applied at 276 N tree? 1 yr?1 and the Zn source was zinc sulfate (ZnSO4,7H20, 23% Zn) applied at 110 g Zn tree? 1 yr? 1. The soil treatments of N and Zn, were applied every two weeks during June through August (total of 6 times/year) in a 1 m radius around the tree trunk (drip line of trees). The foliar solutions of N (10 g l? 1 urea) and Zn [8 g l? 1 zinc sulfate (ZnSO4)] were sprayed at the rate of 10 L tree? 1 every two weeks at the same times as described for soil applications. The highest yield (49 kg tree? 1), and the heaviest fruits (202 g) were obtained in the soil and foliar combination of N+Zn treatment. The lowest yield (35 kg tree? 1), and the smallest fruits (175 g) were recorded in the control. Nitrogen, and to a lesser extent Zn, foliar application resulted in decreasing fruit quality (caused russeting, and lower soluble solid), but increasing N leaf and fruit concentrations (2.4% DW and 563 mg kg? 1, respectively). There were significant differences among yield and leaf mineral nutrient concentration in different treatments. But there was no significant difference between fruit mineral nutrient concentration (except N). Ratio of N/calcium (Ca), potassium (K)/Ca, and [magnesium (Mg)+K]/Ca in fruits were found suitable for fruit quality prediction. Combining the zinc sulfate with urea in the foliar applications increased the concentration of Zn from 0.7 to 1.5 mg per kg of apple tissue. Leaf N concentration varied during growth season. Foliar applied nutrient can be more efficient than soil applied, but a combination of soil and foliar applications is recommended for apple tree nutrient management.  相似文献   
107.

Soybean mosaic virus (SMV) is a member of genus Potyvirus, which causes worldwide soybean [Glycine max (L.) Merr.] yield loss and seed quality deterioration. It is of great significance to find new resistance loci and genes for cultivation of soybean variety. In the present study, a recombinant inbred line (RIL) population and a genome-wide association study (GWAS) panel, which contained 193 lines and 379 germplasms, respectively, were used for QTL mapping of resistance to SMV. Linkage mapping identified a major QTL, qSMV13, on chromosome 13, conferring resistance to SMV SC3 and SC7 strains, explaining phenotypic variations 71.21 and 76.59?%, respectively. The QTL qSMV13 was located close to the known SMV resistance loci Rsv1-h. GWAS analysis revealed five single nucleotide polymorphisms (SNPs) significantly associated with resistance to SC3 on chromosomes 2, 11, 13, 14 and 16. One of the SNP markers, ss715614844, was the right flanking marker of qSMV13. Combining linkage mapping and GWAS analysis enabled us to delimit qSMV13 in a 97.2-kb genomic region containing seven genes. A LRR-RLK protein was proposed as the candidate gene of qSMV13. These results provided selection markers and candidate genes for SMV resistance in soybean molecular breeding programs.

  相似文献   
108.
1. The objective of this study was to determine the prevalence and antimicrobial resistance of Arcobacter spp. isolated from different species of retail poultry meat in Iran.

2. From August 2012 to April 2013, a total of 540 raw poultry meat samples from chicken (n = 100), turkey (n = 100), quail (n = 100), partridge (n = 80), duck (n = 50), ostrich (n = 60) and geese (n = 50) were purchased from randomly selected retail outlets in Shahrekord, Isfahan, Sari and Rasht, Iran.

3. Using culture techniques, 71 of 540 poultry meat samples (13.1%) were positive for Arcobacter spp. The highest prevalence of Arcobacter spp. was found in chicken meat (28.0%), followed by quail (12.0%), duck (11.4%), turkey (11.0%), geese (8.0%), partridge (7.5%) and ostrich (3.3%) meat. The number of A. butzleri isolated from poultry meat samples (90.1%) was significantly higher than A. cryaerophilus (7.1%) and A. skirrowii (2.8%). Significantly more poultry meat samples were found to contain Arcobacter spp. by the PCR assay than by the culture method.

4. Susceptibilities of Arcobacter isolates were determined for 14 antimicrobial drugs using the disk diffusion method. All of the 71 Arcobacter isolates tested were resistant to one or more antimicrobial agents. Resistance to cephalothin and vancomycin (95.8%) was the most common finding, followed by resistance to methicillin, azithromycin and ampicillin. All Arcobacter isolates were susceptible to gentamicin, streptomycin, tetracyclin and kanamycin.

5. The results of this study indicated the importance of poultry meat, especially chicken meat, as potential sources of Arcobacter spp. infection in people. Furthermore, the strains indicated resistance to a broad spectrum of antibiotics.  相似文献   

109.
The city of Tehran,like many polluted metropolises of the world,has higher emissions of greenhouse gases than other cities in Iran,due to heavy consumption of fossil fuel and landuse changes.To estimate carbon sequestration in two 40 year-old stands of planted Cupressus arizonica and Fraxinus rotundifolia in degraded lands surrounding Tehran,sampling of above-and below-ground biomass,soil(at two depths of 0-15 and 15-30 cm),and leaf litter was done by systematic random sampling.The total carbon stocks of C.arizonica and F.rotundifolia stands were respectively 328.20 and 150.69 Mg·ha-1.The aboveground biomass with 233.16(71%)Mg·ha-1 in C.arizonica and88.16(58.50%)Mg·ha-1 in F.rotundifolia contributed the most shares to carbon sequestration.The diameter at breast height,total height,basal area,total volume,and biomass of C.arizonica were significantly(p0.01)higher than those of F.rotundifolia.Also the depth of 0-30 cm of soil contributed between 18.29%and 32.15%of total ecosystem carbon,respectively.The economic value of carbon sequestration in the two stands in 2011 was calculated at 3.5 and 2.5 million dollars,respectively.Our results indicate that afforestation of the degraded land surrounding Tehran would sequester more carbon than would continuously degraded land,the current status quo.These stands can absorb atmospheric CO2 at different rates,thus tree species selection and stand development should be considered in planning future afforestation projects.  相似文献   
110.
The purpose of the study was to investigate the prevalence of gastric lesions and to provide diagnostic values for serum pepsinogen in non-infected pigs and in pigs with gastric disease. In an abattoir survey, the pepsinogen concentrations were measured in the serum from 62 non-infected pigs, 33 pigs with gastric lesions and 17 pigs infected with Hyostrongylus rubidus, using a specific radioimmunoassay (RIA). The mean (±SE) pepsinogen concentrations in the serum of non-infected pigs, in pigs with gastric ulcers, and in pigs with a heavy H. rubidus infection were 630.8±39.2 ng/ml, 1084.5±166.2 ng/ml and 1095.2±102.3 ng/ml, respectively (p<0.05). Because of the higher concentrations of pepsinogen in the blood of pigs with gastric ulcers or parasitic infections, it is suggested that the measurement of serum pepsinogen by RIA may be an effective biochemical approach to the diagnosis of chronic gastric disorders in pigs.  相似文献   
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