The effect of in planta TIBA and proline treatment on somatic embryogenesis of sugar beet (Beta vulgaris L.)

The effect of in planta TIBA and L-proline onin vitro seedlings and cell culture of sugar beet was investigated. Sterilized seeds were grownin vitro on 1/2 MS medium supplemented with 0 or3 mg/l TIBA. Calli obtained on young leaves cultured on MS medium containing 1 mg/l BAP, were used for the initiation of cell suspension cultures using MS basal composition supplemented with 0 or 50 mM proline. Aliquots of 1 ml from cell suspension culture were inoculated onto the first somatic embryo induction MS medium containing TIBA 0.5 mg/l, BAP 1.0 mg/l, and proline at 0 or 50 mM. After three weeks of culture, embryogenic calli were transferred to the second embryo induction medium supplemented with NAA and BAP at 0.2 and 0.5 mg/l, respectively. The frequency of somatic embryos of calli obtained from in plantaTIBA together with proline treatments on average was20 which was higher than that of the other treatments. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effects of nitrogen form of nutrient solution on uptake and concentration macro element and morphological trait in hydroponic tulip

Effects of nutrient solution composition ratio on (Tulipa gesneriana L.) cv, ?Apricot Parrot? and ?Daytona? growth and flowering were studied hydroponics. Plants were grown with five treatments respectively: S₁(0), S₂(0.01), S₃(0.02) S₄(0.03) and S₅(0.04) meq L^.-1 ammonium or 0,0.38, 0.74, 0.11 and 0.14 ammonium (NH₄⁺)/NH₄+nitrate (NO₃)^?ratios. Flowering was accelerated by increase of ammonium level for both cultivars. Nutrition solution was not significant on the stem length of Daytona cultivar, but maximum flowering stem length occurred S₂ solution for Apricot Parrot cultivar. Increasing ammonium level, decreased potassium concentration in the aerial parts. Total nitrogen of new bulbs decreased with increasing ammonium level for both cultivars. Maximum bulblet production rate occurred in plants that were fed with S₅ solution. Maximum flower longevity was in S₂ solution for both cultivars. growth and quality of tulip were affected by ammonium level in nutrient solution, so for obtain the best flower quality must added to nutrient solution.     

Hemato-immunological responses of Heros severus fed diets supplemented with different levels of Dunaliella salina

In this study, the effects of oral administration of different levels of Dunaliella salina (a natural β-carotene source) on growth parameters, immunological and hematological indices, as well as skin carotenoids, of Heros severus were investigated. One hundred and eighty H. severus weighing 27 ± 0.5 g were divided randomly into four groups in triplicate (15 fish in each replicate). Groups 1–4 received food supplemented with 0, 50, 100 and 200 mg kg^?1 D. salina powder, respectively. After 6 weeks, the growth parameters were compared among the groups. Blood samples were taken from each group, and hematological parameters including red blood cell count (RBC), white blood cell count (WBC), hematocrit (PCV), hemoglobin (Hb) and immunological indices (serum and mucus lysozyme and bactericidal activity, resistance against Aeromonas hydrophila infection) as well as carotenoid content of skin were evaluated. Results showed that some growth indices increased significantly in fish fed with 100 and 200 mg kg^?1 D. salina-supplemented food (P < 0.05). Although serum lysozyme activity was increased in fish fed with food supplemented with 100 and 200 mg kg^?1 D. salina (P < 0.05), no significant change was observed in serum and mucus bactericidal activity and mucus lysozyme activity among the groups (P > 0.05). Most of the hematological parameters such as WBC, RBC, PCV and Hb significantly increased in D. salina-treated fish compared with controls (P < 0.05). Mortality induced after challenge with A. hydrophila in 200 mg kg^?1 D. salina-treated fish was 36.67 %, which significantly decreased compared with control (P < 0.05). Skin carotenoid content in all D. salina treatments was statistically higher than that of control (P < 0.05). Conclusively, D. salina as a food additive can affect positively the growth, immunological and hematological parameters of H. severus.     

Current status,opportunities, and challenges of cover cropping for sustainable dryland farming in the Southern Great Plains

Cropping systems that integrate cover crops into crop rotations, reduce tillage intensity and frequency, and maintain residue cover have the potential to improve agricultural sustainability in drylands. However, there is much yet to learn about the benefits of cover crops in sustainable dryland farming in the southern Great Plains (SGP). We reviewed the literature on the effects of cover crops on soil organic carbon (SOC), nitrogen, soil water conservation, and crop yields in dryland cropping systems of the US Great Plains (GP), and analyzed the opportunities and challenges for integrating cover crops into dryland crop-fallow systems of the SGP. Majority of the studies in the central Great Plains (CGP) and the northern Great Plains (NGP) of the United States suggest that cover cropping improves sustainability of cropping systems through their positive effects on SOC accumulation, nutrient cycling, soil erosion control, weed suppression, and soil health improvement. However, integrating cover crops into dryland cropping systems of the SGP faces challenges because of low quantity of soil-water availability. More research on the tradeoff between water use and other agroecosystem benefits of cover cropping is required to successfully integrate cover crops into dryland cropping systems in the SGP.     

Addition of salicylic acid to nutrient solution combined with postharvest treatments (hot water,salicylic acid,and calcium dipping) improved postharvest fruit quality of strawberry

This experiment was conducted to study the effect of salicylic acid addition to nutrient solution and different postharvest treatments on fruit quality of strawberry cv. Camarosa after 7 days at 2 °C. Plants were irrigated with two complete nutrient solutions, with salicylic acid (0.03 mM) or without salicylic acid as the control. Fruits were then treated with eight different postharvest treatments (25 °C water, 45 °C water, 25 °C or 45 °C water containing CaCl₂ (1%), 25 °C or 45 °C water containing salicylic acid (2 mM) and 25 °C or 45 °C water containing both CaCl₂ (1%) and salicylic acid (2 mM)). Fruits which received SA in their nutrient solution had less weight loss and decay and higher firmness. All of the postharvest treatments improved fruit quality characteristics. Fruits dipped in salicylic acid solution had less weight loss, decay and a* (redness) and higher firmness and hue angle than control. Heat treated fruits had less decay and a* and higher hue angle than control. Fruits dipped in CaCl₂ solution had less weight loss, decay and a* and higher firmness than control. Combination of the three postharvest treatments improved firmness, decay, weight loss and vitamin C.     

Growth performance,blood biochemical parameters,immune response,and antioxidant defense of Asian seabass (Lates calcarifer) fingerlings exposed to monovalent and bivalent vaccines against Streptococcus iniae and Vibrio harveyi

The present study investigated the effects of monovalent and bivalent vaccines against Streptococcus iniae and Vibrio harveyi on growth performance, blood biochemical parameters, immune system, and antioxidant defense of Asian seabass (Lates calcarifer) fingerlings. Fish were exposed to seven experimental groups containing phosphate buffer saline (control), S. iniae vaccine by injection, S. iniae vaccine by immersion method, V. harveyi vaccine by injection, V. harveyi vaccine by immersion method, S. iniae/V. harveyi vaccines by immersion method, and S. iniae/V. harveyi vaccines by injection in triplicate for 60 days. Vaccination resulted in a significant alteration of the final weight (FW), feed conversion ratio (FCR), daily weight gain (DWG), relative growth rate (RGR), glucose, lysozyme, and complement levels at 60 days post-vaccination. Also, serum glutathione activity significantly increased in group SVIM (S. iniae/V. harveyi vaccines by immersion method) compared to the control group at 60 days post-vaccination. The level of MDA in serum was significantly decreased in SIN (S. iniae vaccine by injection) and SVIM groups compared to the control group 60 days post-vaccination where the value of this parameter was significantly higher in VIM (V. harveyi vaccine by immersion method) and SVIN (S. iniae/V. harveyi vaccines by injection) groups. The results of this study suggest that exposure to monovalent and bivalent vaccines against S. iniae and V. harveyi could alter the growth performance, nonspecific immune response, and antioxidant defense of Asian seabass fingerlings.

     

Fruit Quality and Nitrogen,Potassium, and Calcium Content of Apple as Influenced by Nitrate: Ammonium Ratios in Tree Nutrition

Evaluations of fruit quality and nitrogen, potassium, and calcium concentration of apple (Malus domestica Borkh. cvs. Gala and Golab) grown with five treatments of NO₃^?:NH₄⁺ ratios were made in pot culture. The concentrations of NO₃^?:NH₄⁺ ratios were 2.5:0.1, 6:1, 6:0.7, 6:0.5, 6:0.3 meq L^?1. Fruit size, percent dry matter, total dissolved solids, total acidity, or juice pH was not affected by increased ammonium in the ratio. Firmness decreased as the proportion of NH₄⁺ increased. Gala and Golab differed in some of these parameters. Concentrations of N and K increased as NH₄⁺ increased, whereas Ca had no trend or decreased. Generally, the treatment of 2.5:0.1 produced fruits with lower N but higher K and Ca concentrations than the other treatments. This research showed that some parameters such as fruit weight, length, and diameter, juice pH, and dry matter were not affected significantly by NH₄⁺ concentration whereas composition was affected.     

Effects of light,sucrose, and cytokinins on somatic embryogenesis in Lilium ledebourii (Baker) Bioss. via transverse thin cell-layer cultures of bulblet microscales

Summary

This is the first report describing the culture conditions necessary to induce somatic embryogenesis and plantlet regeneration from transverse thin cell-layers (tTCL) of the rare and endangered bulb species, Lilium ledebourii (Baker) Boiss. (Liliaceae). The tTCLs were transferred onto 1.0 Murashige and Skoog medium (MS) containing various sucrose concentrations [3.0, 4.5, or 6.0% (w/v)] and different combinations of two cytokinins [6-benzylaminopurine (BA) or thidiazuron (TDZ)] with 1.0 µM -naphthaleneacetic acid (NAA) in the dark, or exposed to light (40 µmol m^–2 s^–1). The aims of this work were to provide an improved propagation method torescue L. ledebourii, and to determine the effects of sucrose concentration, light, and different cytokinins on somatic embryogenesis. Embryogenic callus cultures were obtained only when the tTCLs were transferred onto 1.0 MS medium containing 1.0 µM NAA, various levels of BA (0.4, 1.1, or 2.2 µM), and sucrose [3.0, 4.5, or 6.0% (w/v)] after 3 months culture in the light or in darkness. Combinations of various concentrations of TDZ and NAA did not generate embryogenic calli. The highest rate of growth of embryogenic calli was achieved on 1.0 MS medium supplemented with 1.0µM NAA, 1.1 µM BA, and 4.5% (w/v) sucrose, in the light. Embryo-like structures were grown into plantlets after transfer onto 1.0 MS medium without any plant growth regulators and incubated in the light. Regenerated plants were successfully acclimatised to ex vitro conditions, with a survival rate of 90%.     

Influence of humic acid and salicylic acid on yield,fruit quality,and leaf mineral elements of strawberry (Fragaria × Ananassa duch.) cv. Camarosa

A greenhouse experiment was conducted to evaluate the effects of foliarly-applied Humic Acid (HA) and Salicylic Acid (SA) on strawberry (Fragaria × Ananassa cv. Camarosa). On average, HA applications, regardless of concentration, increased overall yield, Soluble Solids Concentrations (SSC), Titratable Acidity (TA), vitamin C, red tone (a*), leaf potassium (K), phosphorus (P), calcium (Ca) and magnesium (Mg) while had no effect on pH and fruit luminosity (L*). In contrast, fruit from the untreated control tended to have higher Total Antioxidant Capacity (TAC) and SSC: TA ratio than HA-treated plants. Application of SA significantly increased yield, vitamin C, SSC, SSC: TA ratio, TAC, a*, leaf P and Ca while had no effect on TA, fruit size, L* and pH. In general, application of either HA at 25 mg L¹ or SA at 2 mM resulted in better strawberry performance than did other rates of these compounds.