Effect of thiamine injection on growth performance,hematology and germinal vesicle migration in sterlet sturgeon Acipenser ruthenus L.

The present study aimed to investigate the effect of thiamine on growth, hematological, egg thiamine content and oocyte nucleus migration indices in sterlet sturgeon (Acipenser ruthenus). A total of 45 female fish (698.6 ± 8.9 g) were distributed in nine fiberglass tanks with three treatments (each in three replicates). Experimental fish were fed once a day with practical diet supplemented with 1 g kg^?1 amprolium hydrochloride (as the antithiamine) for 5 months before spawning. Thiamine hydrochloride was injected to fish with one of three doses at 0, 5 and 50 mg kg^?1 body weight (BW) at three different stages. At the end of each month, fish were weighed and growth parameters such as weight gain, specific growth rate, feed efficiency and final weight were determined. At the end of the 5-month period, hematological parameters and egg thiamine content were measured. The results showed no significant differences in terms of growth performance. Hemoglobin, number of red blood cells and white blood cells were not significantly different among the treatments, but hematocrit was significantly higher in fish injected with 5 mg kg^?1 BW thiamine. The mean corpuscular volume and mean corpuscular hemoglobin were not significantly different, but lower value of mean corpuscular hemoglobin concentration was observed in fish injected with 5 mg thiamine. Percentage of lymphocytes, neutrophils, eosinophils and monocytes were not significantly different among treatments. The results of the germinal vesicle migration index at different stages showed no significant differences in different groups. Results showed that free thiamine, thiamine pyrophosphate and total thiamine in eggs significantly increased at 50 mg kg^?1 injection dose compared with the control, but no significant different was found in thiamine monophosphate. The results revealed that thiamine injection to sterlet broodstocks has positive accumulation in egg thiamine content and some hematological parameters but have no effect on growth and ovarian maturation. We conclude that thiamine can affect some physiological features of broodstock, which needs to be specified in further studies.     

Regenerating salt tolerant saffron (Crocus sativus) using tissue culture with increased pharmaceutical ingredients

Due to its vegetative reproduction, saffron has a narrow genetic base and induced in vitro variations provide opportunities for expanding new cultivars. The objectives of this study were to evaluate sodium azide-induced variations in saffron’s corm culture in order to increase salt tolerance and pharmaceutical ingredients. Corm explants from the well-known ecotypes, Estahban and Kashmar, were subjected to various concentrations of sodium azide (NaN₃) (0.09, 0.12, and 0.22 mg L^?1) and NaCl (1.5, 2.5, and 4.0 dS equivalent to 0.07, 0.12, and 0.20 g NaCl in 100 mL water) in Murashige and Skoog medium supplemented with 1 mg L^?1 2-4-D, 1 mg L^?1 BAP, and 30 g L^?1 sucrose and in a second pot culture experiment. The active pharmaceutical ingredients (crocin, picrocrocin, and safranal) were measured by high-performance liquid chromatography (HPLC). Variations in sodium azide-treated plants were more broadened for callus fresh weight (0.57–7.57 g), embryo weight (1.24–10.29 g), and regenerated seedlings (3.0–21.25) compared with those (0.12–3.77 g, 0.56–4.56 g, and 0.25–11.50, respectively) that were not treated with sodium azide. Under 0.20% salt, flowering failed in some of plants developed from sodium azide-untreated corms. HPLC analysis indicated wider ranges for crocin (11.92–18.03 mg g^?1), picrocrocin (8.99–14.76 mg g^?1), and safranal (2.13–7.36 mg g^?1) in sodium azide-treated plants compared to the ranges (0.0–16.1, 0.0–12.5, and 0.0–6.66 mg g^?1, respectively) in untreated plants. From a breeding perspective, induced variations found in this study would be useful to improve saffron’s quality and salt tolerance.     

Phylogenetic analysis of the lumpy skin disease viruses in northwest of Iran

Lumpy skin disease (LSD) is a devastating viral disease of cattle which has recently spread from Africa into the countries of the Middle East. The aim of the present study was to investigate the relationships among lumpy skin disease viruses (LSDV) isolated from different regions of Iran and the origin and spread of these viruses. In this study, a total of 234 blood samples from clinically affected animals from four provinces in the northwest of Iran were screened for LSDV using polymerase chain reaction (PCR). From 80 positive samples for LSDV detected by PCR, the partial P32 gene (759 bp) of 12 isolates were sequenced and phylogenetically analyzed. LSD viruses were grouped in three subclusters with an overall 97.1–100% nucleotide identity. LSDVs isolated from Gilan showed lowest nucleotide identity with the other LSDVs. Four isolates of LSDV including KO-1, EA-1, EA-3, and WA-3 showed 100% similarity with each other and also with the Neethling strain. Phylogenetic analysis indicated that the identified LSDVs were closely related to each other and had high-sequence homology with other LSDV isolates from Africa. It was concluded that LSD outbreak probably occurred in the northwest of Iran by LSDVs entering the country from Iraq and P32 nucleotide sequence information obtained in the present study is a valuable resource in understanding the genetic nature and molecular epidemiology of local LSDV isolates which can be used for future vaccine development based on the circulating strains in the region.     

Stress responses of great sturgeon Huso huso subjected to husbandry stressors

Great sturgeon Huso huso juveniles (sub-yearling; 30–268 g) and adults (12.2 kg) were exposed to different kinds of stressors that are commonly observed in aquaculture practices including density, severe confinement, handling, and sex identification. Blood was taken pre- and post-stress for the measurement of cortisol and glucose concentrations. Results showed that in most cases, primary (cortisol) and secondary (glucose) responses of fish to stressors significantly increased. Some different responses were observed between low and high densities as well as male and female. In many cases, stress metabolites decreased to the initial levels at 9–12 h after stress. Results revealed that responses to the stressors in sturgeon are not high as like as teleosts. We established that acute stressors cause a stress response in different size classes of great sturgeon. We characterized the resting profile for cortisol and determined the dynamics of this hormone as well as under simulated management stressors. With this information, we can start the development of management practices (such as anesthesia and appropriate density and handling) that would eliminate stressors interfering with production performance and well-being of the animal in aquaculture. To achieve this, potential stressors should be avoided and possible procedures and techniques can be used or modified to reduce the degree of stress on the fish as much as possible.     

Egg cortisol response to stress at early stages of development in Persian sturgeon Acipenser persicus

One of the most important periods in artificial breeding of sturgeon is incubation. In general, little is known about ontogeny of the stress response in early developmental stages of sturgeon. In this study, cortisol content was measured by radioimmunoassay for the first time in eggs of Persian sturgeon Acipenser persicus to elicit at which times during early developmental stages, that they were particularly sensitive to stressful events. In this study, fertilized eggs of mature Persian sturgeons were placed in special boxes (as replicates) that were put in incubation units of Yushchenko. To assess pre-stress samples (resting cortisol levels), 5 eggs were selected randomly from each box in 7 important stages of incubation (2-cell division, blastula, end of blastula, mid of gastrula, neurula, eyed stage and heart beaten). In another experiment, eggs were exposed to an acute stress (10 min out of water) in 7 developmental stages. For determination of post-stress cortisol, eggs were collected 2 and 6 h after the stress. The results indicated significant difference in various stages of incubation but cortisol levels revealed no differences in whole-body levels between stressed samples (2 and 6 h post-stress) and unstressed samples (P > 0.05). The highest percentage of hatching rate for post-stressed eggs was recorded in 2-cell division stage while this percentage declined steadily in the heart beaten stage when a statistically significant difference was revealed with regard to other stages (P = 0.000). These findings suggested that sturgeon eggs were not so much sensitive in their early developmental stages and relatively resistant to stress. However, significant decrease in survival rate in heart beaten stage showed a sensitivity of this stage to stress. Lack of an increase in cortisol after acute stress indicated that hypothalamus-pituitary-interrenal (HPI) axis for cortisol synthesis was not yet functional. However, further studies seem necessary to clarify when HPI axis is activated in this species.     

Application of half-sib mating for genetic analysis of forage yield and related traits in Bromus inermis

Despite efforts made, forage yield of smooth bromegrass has increased slowly over the last 50 years of breeding. It therefore seems necessary to investigate more on the genetic basis of agro-morphological traits in this cool-season, highly drought resistant grass. The present study was aimed at estimation of total genetic variance, narrow-sense heritability, general combining ability, phenotypic and genotypic correlation among different quantitative traits in half-sib (HS) families derived from polycross of 25 smooth bromegrass genotypes that were mainly originated from Iran. Families differed significantly for all of the agro-morphological and quality traits measured. Narrow sense heritability ( ${\text{h}}_{\text{n}}^{2}$ ) ranged from about 0.2 (plant height) to 0.7 (day to inflorescence emergence and day to anthesis). Moderate to high heritability for forage dry matter yield (0.42) indicates that phenotypic selection for this trait can be successful. A wide range of general combining ability was observed for most of the studied traits, especially those related to forage yield. Relatively low genetic variation and heritability for crude protein and also negative correlation of this trait with forage yield, indicates a low probability of improving forage yield and quality simultaneously.     

Determinants of Summer Nitrate Concentration in a Set of Adirondack Lakes,New York

Following reductions in the emission and deposition of sulfur compounds in the past decade, atmospheric deposition of nitrogen has become a focus of concern. Identification of watershed characteristics that mediate the effect of atmospheric nitrogen deposition can help evaluate the sensitivity of lakes to chronic and episodic nitrogen addition. Twenty four lakes in the southwestern portion of the Adirondack Park, New York, U.S.A., were classified into three N classes by cluster analysis of lakewater NO3- N concentration [N] during the summers of 1994–1996. The lake-N classes were best characterized as having (1) low [N] throughout the summer, (2) high [N] in early- but low [N] in late-summer, and (3) high [N] throughout the summer. The three lake-N classes were reconstructed perfectly by canonical discriminant analysis based mainly on lake average depth (AD), and lakewater concentrations of chlorophyll a [Chla] and SO4-S [S] in mid-summer. Increases in AD and [S], but decrease in [Chla] corresponded with a transition from low- to high-N classes.