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1.
The aim of current study was to review breeding progress and update information on genetic strategies in Iranian buffaloes. Iranian buffalo is one of the vital domestic animals throughout north, north-west, south and south-west of Iran with measurable characteristics both in milk and meat production. The species plays an important role in rural economy of the country due to its unique characteristics such as resistance to diseases and parasites, having long productive lifespan and showing higher capability of consuming low-quality forage. In Iran, total production of milk and meat devoted to buffaloes are 293,000 and 24,700 tons, respectively. Selection activities and milk yield recording are carrying out by the central government through the Animal Breeding Centre of Iran. The main breeding activities of Iranian buffaloes included the estimation of genetic parameters and genetic trends for performance traits using different models and methods, estimation of economic values and selection criteria and analysis of population structure. Incorporating different aspects of dairy buffalo management together with improved housing, nutrition, breeding and milking, is known to produce significant improvements in buffalo production. Therefore, identifying genetic potential of Iranian buffaloes, selection of superior breeds, improving nutritional management and reproduction and developing the education and increasing the skills of practical breeders can be useful in order to enhance the performance and profitability of Iranian buffaloes.  相似文献   
2.
With respect to bacterial natural products, a significant outcome of the genomic era was that the biosynthetic potential in many microorganisms surpassed the number of compounds isolated under standard laboratory growth conditions, particularly among certain members in the phylum Actinobacteria. Our group, as well as others, investigated interspecies interactions, via co-culture, as a technique to coax bacteria to produce novel natural products. While co-culture provides new opportunities, challenges exist and questions surrounding these methods remain unanswered. In marine bacteria, for example, how prevalent are interspecies interactions and how commonly do interactions result in novel natural products? In an attempt to begin to answer basic questions surrounding co-culture of marine microorganisms, we have tested both antibiotic activity-based and LC/MS-based methods to evaluate Micromonosporaceae secondary metabolite production in co-culture. Overall, our investigation of 65 Micromonosporaceae led to the identification of 12 Micromonosporaceae across three genera that produced unique metabolites in co-culture. Our results suggest that interspecies interactions were prevalent between marine Micromonosporaceae and marine mycolic acid-containing bacteria. Furthermore, our approach highlights a sensitive and rapid method for investigating interspecies interactions in search of novel antibiotics, secondary metabolites, and genes.  相似文献   
3.
In this study, interactions of nickel sulfate and urea sprays on vegetative growth, yield and leaf mineral contents in strawberry were investigated. Rooted Pajaro strawberry plants were potted in 3 liter pots filled with soil, leaf mold and sand (1:1:1, v/v/v). Established plants were foliar sprayed with nickel sulfate at 0, 150, 300 and 450 mg L?1 and urea 0 and 2 g L?1 concentrations. Results indicated that nickel (Ni; 300 mg L?1) plus urea (2 g L?1) significantly increased the yield and runner numbers. Nickel sulfate at the rate of 300 and 150 mg L?1and urea (2 g L?1) significantly increased the crown numbers. The greatest root fresh and dry weights were obtained from untreated plants. Urea at 2 g L?1 without nickel significantly increased shoot fresh and dry weights. Nickel at 450 mg L?1 without urea significantly increased Ni concentration in leaves. Overall, nickel sulfate at 150 and 300 mg L?1 along with urea at 2 g L?1 were the best treatments.  相似文献   
4.
An experiment was conducted to assess the effect of foliar application of potassium silicate on Cynodon dactylon [L.] Pers., Festuca arundinacea Schreb. and Lolium perenne L. With increased salinity level, chlorophyll content and relative water content (RWC) in these three turfgrasses were reduced significantly when compared with the untreated control. Supplementary silicon (Si) ameliorated the adverse effects of salinity on chlorophyll content. Silicon treatments decreased proline at all salinity levels. Moreover, addition of Si increased shoot length and shoot number in all turfgrasses. Sodium (Na) concentration was increased in both leaves and roots of turfgrasses at high salinity level; however, Si treatment significantly reduced Na concentration in all of them. Silicon increased Potassium concentration in shoots and roots (though not significantly) in most cases. It can be concluded that Si alleviated the adverse effects of salt stress in all turfgrasses.  相似文献   
5.
6.
The effect of three mono‐specific and four combinations of the diatoms Chaetoceros muelleri, Chaetoceros calcitrans, and the chlorophyte Tetraselmis suecica on survival, development, and dry weight of the western school prawn, Metapenaeus dalli, was assessed from protozoea I until mysis I. The development and dry weight of larvae were significantly greater when fed diets comprising C. muelleri and/or T. suecica. A fourth diet, consisting of all three microalgal species also performed just as well. Survival alone was a poor measure of the performance of the various diets. Larvae fed with C. calcitrans, either alone or in a mixed diet with either C. muelleri or T. suecica, had significantly slower development and lower dry weight. Overall performance, assessed using the normalized biomass development index, determined that both mono‐specific and mixed diets containing C. muelleri and T. suecica were among the best for M. dalli larvae. These results for M. dalli are consistent with those found for commercially grown penaeid prawns. This study enhances the limited knowledge on the feeding requirements of metapenaeid prawn larvae. Moreover, the results will help improve hatchery methods for the aquaculture‐based enhancement of M. dalli in the Swan‐Canning Estuary and potentially increase the abundance of this iconic recreational species.  相似文献   
7.
This study was designed to investigate whether the prebiotic mannan‐oligosaccharides (MOS) can reduce the deleterious impacts of feed deprivation on growth and reproduction in zebrafish. In the growth performance experiment, juvenile fish were distributed in the following four treatments: normal‐control (NC), starved‐control (SC), normal‐prebiotic (NP) and starved‐prebiotic (SP). After 8 weeks, NP and SC fish showed the highest and lowest growth patterns, respectively among treatments. Standard length, specific growth rate and feed conversion ratio did not differ significantly between NC and SP treatments. Autochthonous lactic acid bacteria (LAB) were significantly higher in NP and SP than the NC and SP treatments. Feed restriction resulted in significantly lower concentrations of thyroxine. In the reproductive performance experiment, additional juveniles were fed as in the growth experiment. Crossing in the final week of the experiment resulted in successful spawning in only NP fish, which showed mature sperm and oocytes in histological examinations. The number of spermatozoa was significantly lower in the fish that experienced feed restriction; however, the oocytes of SP females were at the same maturation level to that observed in NC females. Sex‐steroids changed after both starvation and MOS supplementation where NC and SP showed no differences in the levels of testosterone and female's 17β‐estradiol. These results indicate that MOS supplemented diet reduced some side effects of feed deprivation (final weight and length, SGR, FCR and levels of LAB and T3), and suggest that supplementation of the diet with MOS may ameliorate some of the negative effects of feed deprivation in zebrafish.  相似文献   
8.
A study was designed to investigate the possible positive prebiotic effects of mannan oligosaccharides (MOS) on growth and reduction of anxiety behaviors in zebrafish (Danio rerio). The experimental diets were supplemented with 0, 2, 4, 6, or 8 g MOS kg?1 and were fed to juvenile fish (0.47 ± 0.017 g) in triplicates for six weeks. Significant differences were found in the final body weight, body weight intake, percent body weight intake, and specific growth rate among treatments. The regression analyses showed that the optimum MOS level was 4–4.1 g MOS kg?1 diet. Fish fed 4 g MOS kg?1 feed showed higher survival than the other treatments. Also, using the novel tank test, fish fed with 4 g MOS kg?1 diet showed lower anxiety by swimming in the upper portion of the tank. The other behavior parameters remained unaffected by the prebiotic. The results indicated the beneficial effect of the prebiotic MOS on growth and partly on welfare of zebrafish juveniles.  相似文献   
9.
Today, due to the rapid spoilage of fish, the use of natural preservatives is a priority over those of synthetic varieties. Also, the natural antimicrobial effects of essential oils can help to increase shelf life. There are very few studies concerning the use of essential oils in this regard. In the present study, the antibacterial effect of chitosan coated with Heracleum persicum oil was investigated on the quality of rainbow trout. The control and the coated fish samples were analyzed periodically by generalized estimating equation (GEE) for total viable count (TVC), psychrophilic bacteria, total volatile base nitrogen (TVB-N), polyunsaturated fatty acids (PUFA), texture, taste, odor, and overall acceptance parameters. The results showed that by increasing the amount of chitosan, TVC, psychrophilic bacteria, and TVB-N decreased while PUFA, texture, taste, odor, and overall acceptance parameters increased.  相似文献   
10.
BACKGROUND: Anopheles culicifacies is a main malaria vector in southeastern part of Iran, bordring Afghanistan and Pakistan. So far, resistance to DDT, dieldrin, malathion and partial tolerance to pyrethroids has been reported in An. stephensi, but nothing confirmed on resistance status of An. culicifacies in Iran. METHODS: In current study, along with WHO routine susceptibility test with DDT (4%), dieldrin (0.4%), malathion (5%), permethrin (0.25%), lambadacyhalothrin (0.1%), and deltamethrin 0.025, we cloned and sequenced segment VI of domain II (SII6) in voltage-gated sodium channel (vgsc) gene of An. culicifacies specimens collected in Sistan and Baluchistan province (Iran). RESULTS: A 221-bp amplified fragment showed 91% and 93% similarity with exon I and exon II of An. gambiae. The size of intron II in An. culicifacies is 62 bp, while in An. gambiae is 57 bp. The major difference within An. culicifacies specimens and also with An. gambiae is in position 29 of exon I, which led to substitution of Leu to His amino acid. CONCLUSION: This data will act as first report on partial sequence of vgsc gene and its polymorphism in An. culicifacies. A Leu to His amino acid substitution detected upstream the formerly known knockdown resistance (kdr) mutation site could be an indication for other possible mutations related to insecticide resistance. However, the result of WHO susceptibility test carried out in Baluchistan of Iran revealed a level of tolerance to DDT and dieldrin, but almost complete susceptibility to pyrethroids in An. culicifacies. We postulate that the molecular diagnostic tool developed for detection and identification of kdr-related mutations in An. culicifacies, could be useful in monitoring insecticide resistance in Iran and neighbouring countries such as Pakistan and Afghanistan. A phylogenetic tree also constructed based on the sequence of exon I and II, which readily separated An. culicifacies populations from An. stephensi, An. fluviatilis and An. gambiae.  相似文献   
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