The objective of this study was to investigate the effect of three methods of oral selenium-enriched yeast (Se-yeast) supplementation on the blood characteristics and growth of Holstein dairy calves. The three methods were: (1) maternal (dams supplemented with 0.3 mg Se per kg of dietary DM during 3 weeks pre-calving), (2) post-calving (calf starter enriched with 0.3 mg Se per kg of DM), and (3) maternal and post-calving Se-yeast supplementation. These three methods were compared with a control group (no supplementation). Maternal supplementation with Se-yeast successfully increased Se concentration in the colostrum and the serum of calves 24 h after calving (P < 0.05). At day 56, the Se concentration in the blood of calves supplemented with Se-yeast pre- (maternal) or post-calving (via starter) was greater than the control group (P < 0.05), but maternal plus post-calving supplementation was not more effective than either maternal or post-calving supplementation. Globulin and total protein concentration in the blood of calves at day 0 increased and albumins:globulins decreased with maternal supplementation (P < 0.05), but these variables were similar for all treatments at day 56. Immunoglobulins in the blood of calves and colostrum were not affected by maternal Se-yeast supplementation. Maternal supplementation increased the concentration of urea in the blood of calves at 0 days (P < 0.05), but not at 56 days. Calf birthweight was increased with maternal supplementation of Se-yeast (P < 0.01), but growth to day 56 was not affected by the methods of Se supplementation. Maternal supplementation with Se-yeast may improve growth and health characteristics of calves at calving time.

Aims: Using rhizobacteria as plant growth-promoting agents for improving heavymetal phytoremediation processes in contaminated soil has attracted a lot of attention mainly because of their eco-friendliness. The aim of this study was the evaluation of lead phytoremediation by Carthamus tinctorius improved with the isolated and molecularly identified lead-resistant rhizobacteria. Methods and Results: Rhizobacteria were isolated from C. tinctorius root and was identified using macroscopic and microscopic characteristics, biochemical testing and PCR. Then, the indole acetic acid production and phosphate-solubilizing activity were determined. Finally, the amount of lead in the plant was measured by atomic absorption method. Five strains of Bacillus cereus, Bacillus muralis, Bacillus sp., Pseudomonas fluorescens and Brevibacterium frigoritolerans with the ability of mineral phosphate solubilizing, high levels of indole acetic acid production and resistance to lead were isolated from the rhizosphere of C. tinctorius. The amount of produced indole acetic acid and the level of phosphate solubilizing by the isolates were 7.1-69.54 µg ml −1 and 91-147.3 µg ml −1 respectively. Lead assimilation in aerial part of safflower ranged from 925 to 2175 ppm. P. fluorescens and B. cereus strains had the highest effect on Lead assimilation with 2175 and 1862 ppm respectively. Conclusions: The results showed that different bacterial treatments influenced the rate of lead absorption by C. tinctorius exposed to lead stress. Significance and Impact of the Study: Use of rhizosphere isolates of C. tinctorius can improve phytoremediation capability and lead absorption in leadcontaminated soil.

Rhizospheric bacteria are among the beneficial soil microorganisms that improve plant growth. These bacteria increase plant growth through various mechanisms such as the production of various phytohormones and the ability to solubilize phosphate. The aim of this study was to investigate the effects of rhizosphere bacteria on the growth of Carthamus tinctorius to improve its physiological and biochemical indicators. Carthamus tinctorius seeds were inoculated with five isolates of rhizosphere bacteria and were then planted the seeds in pots. Subsequently, the physiological and biochemical parameters of the plants, including the rates of auxin production, phosphate dissolving, photosynthetic pigments and the contents of proline and malondialdehyde were measured. For this purpose, a factorial experiment were conducted using a completely randomized design with three replications. The ANOVA was performed and a comparison of the means was carried out using Duncan's multiple range test. The results indicated that the largest stem fresh weight, root fresh and dry weights observed in the treatments of using Pseudomonas fluorescens (auxin concentration of 23.55 μg/mL) and Bacillus muralis (auxin concentration of 22.27 μg/mL). In addition, all bacterial species increased the safflower seed germination rate compared to the control group. The largest malondialdehyde content was recorded in the treatment with Bacillus albus, and MDA content decreased in the treatments that produced larger amounts of auxin. In general, the finding of this research suggested that bacterial inoculation was capable to significantly affect the growth of safflower and improve its qualitative and quantitative growth parameters.