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51.
A karyotype study was performed on 15 populations of Eremostachys laciniata Bunge from Iran in order to quantify the extent of cytological variation for use in breeding programmes. Ten mitotic root tip cells at the metaphase stage were prepared from each population by the squash method. The chromosomes of suitable mitotic cells were counted and various parameters, including long and short arm lengths, chromosome lengths, total length of the haploid chromosome complement, arm ratios, and the centromeric index, were measured. All 15 populations were diploid with 2n = 2x = 22 and were differentiated by their karyotypic parameters. All 15 E. laciniata populations occupied Class 1A of Stebbins’ karyotype classification, indicating the presence of a primitive symmetrical karyotype. The size of the mitotic chromosomes was medium, and mean chromosome lengths ranged from 3.84 to 4.77 μm. The shortest chromosome lengths were observed in the Ajabshir population and the longest in the Heydarabad population. The Heydarabad population also had the longest total chromosome length and the Ajabshir population had the shortest total chromosome length. The centromeric indices of the chromosome complements varied from 39.3% to 43.7%. Metacentric chromosomes were the most common in all populations, whereas submetacentric chromosomes were rare. The A1 index varied from 0.215 (Areshtanab) to 0.337 (Til). The A2 index ranged from 0.116 (Til) to 0.143 (Kaleybar), and the karyotype asymmetry index varied between 0.051 and 0.097. The results of a principal component analysis (PCA) showed that the main elements of the first three main principal components accounted for 97% of the total variance. Cluster analysis by Ward’s method indicated that all 15 populations could be classified into three clusters. Finally, the results of the karyotypic parameters showed that the Til, Heydarabad, and Marand populations had higher levels of karyotypic heterogeneity and may be useful when developing breeding programmes.  相似文献   
52.
Fire products have been widely identified as germination cues for a number of species from both fire-prone and fire-free ecosystems. However, there is uncertainty about the effects of fire products on seed germination of semi-arid rangeland species. We examined the germination of seven dominant species from Central Zagros rangelands in the semi-arid region of Iran under various heat shock (60, 80 and 120 °C), aerosol smoke, ash and control treatments. Our findings showed that fire products could enhance, inhibit or not affect the seed germination of rangeland species in this area. The germination percentage of Astragalus adscendens increased following 60 °C heat treatment in comparison with the control. The germination of Astragalus verus, Bromus tectorum, B. tomentellus and Phlomis olivieri were increased significantly using smoke treatment (P<0.0001). The seed germination of B. tomentellus and B. tectorum was promoted by ash treatment, whereas the other species exhibited no response or were inhibited by fire products. In addition, smoke treatment shortened the overall germination time of B. tectorum. These findings suggest that fire products affect the germination of several species and can serve as potential tools for understanding the vegetation dynamics and restoration of disturbed semi-arid rangelands.  相似文献   
53.

Field experiments were conducted on wheat during 2017–2018 and 2018–2019 under rainfed conditions. The statistical significance between treatment means was determined at 5% significance level. Data were recorded on weed density, protein, fat and ash contents of wheat grains. Weed density in shallow tillage was highest (20.67?m?2) while it was lowest (14.23?m?2) in deep tillage. In weed control factor, weed density was highest in weedy check (33.10?m?2), followed by parthenium aqueous extract (21.50?m?2), and lowest (6.79?m?2) in plots treated with Affinity (isoproturon?+?carfentrazone). Results showed that the highest crude protein content (10.88%) was recorded in deep tillage, while lowest (10.45%) in shallow tillage, indicating that tillage depths have an impact on wheat grains protein content. For weed control factor, the crude protein content was highest (11.98%) in Affinity treated plots, followed by herbicides, Buctril super (bromoxynil?+?MCPA) (11.44%) and Puma super (fenoxaprop-p-ethyl) (11.12%). Hence, the control measures also affected crude protein content of wheat grains, which is also obvious from the weedy check where wheat grains crude protein content was lowest (9.73%). The two years combined data analysis also showed the highest crude fat content (1.75%) in deep tillage treatments followed by normal tillage (1.67%) and lowest fat content (1.53%) in shallow tillage. For ash content, the highest content (3.03%) was with Affinity herbicide treatments, followed by Buctril super (2.74%) and Puma super (2.48%) herbicides. In conclusion, both the tillage and herbicides indicated positive effects on the nutritive status of wheat grains.

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54.
Conversion of forest land to farmland in the Hyrcanian forest of northern Iran increases the nutrient input, especially the phosphorus(P) nutrient, thus impacting the water quality. Modeling the effect of forest loss on surface water quality provides valuable information for forest management. This study predicts the future impacts of forest loss between 2010 and 2040 on P loading in the Tajan River watershed at the sub-watershed level. To understand drivers of the land cover, we used Land Change Modeler(LCM) combining with the Soil Water Assessment Tool(SWAT) model to simulate the impacts of land use change on P loading. We characterized priority management areas for locating comprehensive and cost-effective management practices at the sub-watershed level. Results show that agricultural expansion has led to an intense deforestation. During the future period 2010–2040, forest area is expected to decrease by 34,739 hm~2. And the areas of pasture and agriculture are expected to increase by 7668 and 27,071 hm~2, respectively. In most sub-watersheds, P pollution will be intensified with the increase in deforestation by the year 2040. And the P concentration is expected to increase from 0.08 to 2.30 mg/L in all of sub-watersheds by the year 2040. It should be noted that the phosphorous concentration exceeds the American Public Health Association′s water quality standard of 0.2 mg/L for P in drinking water in both current and future scenarios in the Tajan River watershed. Only 30% of sub-watersheds will comply with the water quality standards by the year 2040. The finding of the present study highlights the importance of conserving forest area to maintain a stable water quality.  相似文献   
55.
Agricultural sector is a major source of employment and export earnings for Pakistan. Exports of Pakistan are highly concentrated in agricultural products including cotton, rice, sugar and fruit. This study analyzed comparative and competitive advantages of the main agricultural products of Pakistan, i.e. cotton, rice and tangerines. Consumption patterns of top exporting countries in each category were also analyzed. Results revealed that Pakistan had strong competitiveness for export of these commodities. Strong potential for growth in the agricultural sector of Pakistan was found and it could be optimized to raise export earnings and meet the objectives of the strategic trade policy framework(STPF) 2015-2018 of Pakistan.  相似文献   
56.
European Journal of Plant Pathology - Longidorus armeniacae n. sp. is described and illustrated using morphological and molecular data. It was recovered from the rhizosphere of apricot trees in...  相似文献   
57.
The A Iran 05 foot-and-mouth disease virus (FMDV) subtype was detected in Iran during 2005 and has proven to be highly virulent. This study was undertaken to focus on molecular and phylogenetic analysis of 3A and 3B coding-regions in the A Iran 05 field isolate. To assess the genetic relatedness of A Iran 05 isolate the nucleotide and predicted amino acid sequences of the 3AB region of type A FMDV isolates were compared with twenty previously described type A FMDV isolates. The phylogenetic tree based on the 672 bp 3AB gene sequences of type A FMDV from thirteen different locations clustered them into five distinct lineages. The A Iran 05 isolate clustered in lineage A along with four type A variants and was closely matched with viruses isolated in Turkey and Pakistan during 2005~2006. The number of protein sequence differences exhibited by each of the isolates revealed that A Iran 05 isolate contains three amino acid substitutions at positions 47 and 119 of 3A and 27 of the 3B coding region. The nucleotide identity between A Iran 05 and the other four isolates of lineage A was estimated to be 98%.  相似文献   
58.
The aim of this research was to determine the effect of three different fertilizing systems, including organic, conventional, and integrated ones, on the yield, fruit quality, antioxidant activity, and some phenolic compounds of white seedless grape. The study was carried out on several 6-year-old white seedless grapevine located in the Urmia Province (North-West Iran). The results showed that the fruit physical characteristics and yield were affected significantly by different fertilization systems. The highest yield was observed in the conventional fertilization, followed by organic and integrated systems. The leaf mineral contents were obviously dependent on the different fertilization used, whereas pH and titratable acidity were not affected. Based on our results, the highest values of antioxidant activity and total flavonoid were found in the organic and integrated fertilization systems, respectively. Also, the highest contents of total phenolic, catechin, and quercetin-3-galactoside were observed in the organic fertilization system. Overall, the highest nutritional quality and biochemical characteristics of white seedless grape were obtained in organic fertilization system, which improved antioxidant capacity by enhancing total phenolics, total flavonoids and valuable phenolic compounds.  相似文献   
59.
Summary Pure cultures ofCorynebacterium pseudotuberculosis were obtained from 11 cases of lymphadenitis (known locally as taloa or mala) in camels. Camel isolates produced typical taloa in camels experimentally inoculated subcutaneously at the base of the external ear with 1010 colony forming units. A sheep strain ofC. pseudotuberculosis inoculated into camels produced a local abscess at the site of inoculation but did not produce taloa. Re-infection of camels recovered from experimental inoculation did not produce taloa suggesting the possibility of the development of a vaccine against lymphadenitis in camels.
Infeccion PorCorynebacterium Pseudotuberculosis Y Linfadenitis (Taloa O Mala) En El Camello
Resumen Se obtuvieron cultivos puros deCorynebacterium pseudotuberculosis a partir de 11 casos de linfadenitis (conocida localmente como taloa o mala) en camellos. La inoculación subcutánea en camellos en la base de la oreja de 1010 unidades formadoras de colonias procedentes de un cultivo obtenido de camellos infectados causó taola. Sin embargo, una cepa ovina deC. pseudotuberculosis causó un abceso en el lugar de la inoculación pero no produjo taola en camellos. La reinfección de los camellos que se habían recuperado de la inoculación experimental no causó taola, lo que sugiere la posibilidad de desarrollar una vacuna frente a la linfadenitis caseosa del camello.

Infection ACorynebacterium Pseudotuberculosis Et Lymphadenite (Taloa Ou Mala) Chez Le Chameau
Résumé On a obtenu des cultures pures deCorynebacterium pseudotuberculosis à partir de 11 cas de lymphadénite (dénommée localement taloa ou mala) chez des chameaux. L'inoculation expérimentale des isolements camelins faite en infection sous-cutanée à la base de l'oreille externe avec 1010 unités formant des colonies a provoqué un taloa typique. Une souche ovine deC. pseudotuberculosis inoculée à des chameaux n'a conduit qu'à la formation d'un abcès local au point d'inoculation mais pas au taloa. La réinfection des chameaux guéris d'une inoculation expérimentale ne provoque pas de taloa, ce qui permet d'augurer la possibilité de développement d'un vaccin contre la lymphadénite cameline.
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60.
Owner survey of schitosomiasis mortality in sudanese cattle   总被引:1,自引:0,他引:1  
The estimated mortality in six- to 30-month-old cattle due to presumptive schistosomiasis was 7.1% for 155 interviews conducted in the White Nile Province in 1981. This mortality was higher for those herds under sedentary management than for migratory herds (9.4% vs 3.6%). The interviews were done through an informal visit technique by a veterinarian living in the area. The approximate number (19,000) of cattle over six months old estimated to be owned by those interviewed represents about 1% of the population in that province. The mortality from all causes in the six- to 30-month age group was 9.2%; in the over 30-month age group it was 1.8%. The authors judge the schistosomiasis mortality to be somewhat upwardly biased but the mortality due to all causes (9.2%) is consistent with the few reports available.  相似文献   
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