Evaluation of the effects of spores and their heat-treated residues from different Bacillus strains on the initial growth of rice plants

This study evaluated the effects of the spores and their heat-treated residues from different strains of Bacillus species (B. pumilus, B. altitudinis, and B. megaterium) on the early growth of paddy rice cultivars, including Hitomebore (short-grain japonica rice), Takanari (high-yielding indica rice), and two new lines, TULK-143-6 and LTAT-29. The spores of seven Bacillus strains positively affected Hitomebore root growth, while, the root volume of TULK-143-6 with inoculation of B. pumilus TUAT1 and JM52, and root length and root surface area of LTAT-29 with inoculation of B. megaterium MAFF301694 were increased significantly. In contrast with Hitomebore, Takanari root growth was significantly inhibited by the spores of six Bacillus strains. Surprisingly, inoculations with the spore residues from all tested Bacillus strains increased the root dry weight of Hitomebore, with the effects of four bacterial strains being significant. Furthermore, there were more Bacillus spores than vegetative cells at different time points during the initial rice growth stage, and most plant samples mainly consisted of Bacillus spores. Thus, the spores of Bacillus species likely promote rice root development.     

缺氧诱导因子和促红细胞生成素及其受体基因在绵羊各组织中表达量

【目的】研究缺氧诱导因子(HIF)及其下游靶基因促红细胞生成素(EPO)及其受体(EPOR)在绵羊正常生理状况下各组织的表达,为靶向调控或缓解绵羊缺氧应激的研究提供组织学依据。【方法】采用实时荧光定量PCR方法,检测4只新疆细毛羊14种组织中HIF、EPO和EPOR基因的相对表达量。【结果】HIF-1α和HIF-2α基因均在绵羊肺组织的相对表达量最高,且极显著高于其它组织(P<0.01);在肺脏HIF-2α基因的表达量约为HIF-1α表达量的5.2倍。EPO基因在绵羊肾脏的相对表达量最高且显著高于垂体、结肠、脾脏、盲肠、肝脏、肾上腺、瘤胃、下丘脑以及心脏(P<0.05)。EPOR基因在肺脏的表达量最高,肺脏和睾丸的相对表达量显著高于脾脏、下丘脑、肾脏、心脏等组织(P<0.05)。【结论】HIF-1α、HIF-2α和EPO及其受体基因在绵羊的肺部或肾脏的高表达,可能是绵羊缺氧应激感受及其调控的重要器官。     

The critical period of weed control in soybean (Glycine max (L.) Merr.) in north of Iran conditions

A field study was conducted in 2006 at Sari Agricultural and Natural Resources University, in order to determine the best time for weed control in soybean promising line, 033. Experiment was arranged in randomized complete block design with 4 replications and two series of treatments. In the first series, weeds were kept in place until crop reached V2 (second trifoliolate), V4 (fourth trifoliolate), V6 (sixth trifoliolate), R1 (beginning bloom, first flower), R3 (beginning pod), R5 (beginning seed) and were then removed and the crop kept weed-free for the rest of the season. In the second series, crops were kept weed-free until the above growth stages after which weeds were allowed to grow in the plots for the rest of the season. Whole season weedy and weed-free plots were included in the experiment for yield comparison. The results showed that among studied traits, grain yield, pod numbers per plant and weed biomass were affected significantly by control and interference treatments. The highest number of pods per plant was obtained from plots which kept weed-free for whole season control. Results showed that weed control should be carried out between V2 (26 day after planting) to R1 (63 day after planting) stages of soybean to provide maximum grain yield. Thus, it is possible to optimize the timing of weed control, which can serve to reduce the costs and side effects of intensive chemical weed control.     

Impact of tree species on nutrient stocks in the forest floors of a temperate forest ecosystem

To investigate the effect of silvicultural methods on forest floor C, N and elements stocks an experiment was carried out by sampling the forest floors of a 100-120-years-old species including beech, Norway spruce and mixed beech-spruce at the Solling forest, Germany. While the stocks of carbon and nitrogen in the forest floors of pure beech and spruce were significantly influenced by species specific differences of litter quality (p < 0.001), no significant differences were detected between pure and mixed species stands. Forest floor mass, some elements concentrations and C/nutrient ratios were significantly affected by tree species differences, while no clear dependency between pH and site specific effects was found among pure stands. Acid element concentrations in the forest floors of pure spruce were remarkably higher than the values obtained at beech stand, while the stocks were to some extent modified in mixed silviculture. The base-pump effect of beech significantly controlled variation between mono cultures on calcium stocks, while the acidifying effect of spruce in mixtures resulted in modification of Ca stocks of forest floors. The status of other nutrient elements at mixed species cultures due to variation in nutritional properties and composition of litter compared to pure species were between the range of values observed in mono cultures.     

Studies on the toxicity of acetone, acrolein and carbon dioxide on stored-product insects and wheat seed

In laboratory experiments toxicity of acetone, acrolein and carbon dioxide were investigated against 4 species of stored-product insects. In all experiments, acrolein was the most toxic compound to the tested insects. In empty-space trials, estimated LD50 values of acrolein for adults of Tribolium castaneum (Herbst) (Tenebrionidae), Rhizopertha dominica (F.) (Bostrychidae), Sitophilus oryzae L. (Curculionidae) and Oryzaephilus surinamensis L. (Silvanidae) were 7.26, 6.09, 6.37 and 5.65 microl L(-1), respectively. Penetration tests revealed that acetone and acrolein vapors could penetrate into the wheat mass and kill concealed insects in interkernel spaces. Comparison of LD50 values of acrolein between empty-space tests and penetration experiments indicated that the increase in penetration toxicity was 4.96, 4.54, 3.64 and 3.43-fold for T. castaneum, R. dominica, S. oryzae and O. surinamensis, respectively. The effect of carbon dioxide on the toxicity of acrolein and acetone was synergistic. In the hidden infestation trials, the acrolein vapors destroyed the developmental stages of S. oryzae concealed inside the wheat kernels and resulted in a complete control with concentration of 80 microl L(-1) for 24 h and subsequently observed during 8 weeks after the exposure. Wheat germination and plumule length was reduced following exposure to all doses of acrolein. Acetone and carbon dioxide were harmless to wheat seed viability. The mixture of carbon dioxide with acrolein can be considered as a potential fumigant for replacing methyl bromide or phosphine under ambient storage conditions specifically in empty-space fumigations.     

Flanking SSR markers for alleles involved in the necrosis of hybrids between hexaploid bread wheat and synthetic hexaploid wheat

Hybrid necrosis in wheat (Triticum aestivum L.) is the premature death of leaves or plants caused by the interaction of two dominant complementary genes, Ne1 and Ne2, located on chromosomes 5B and 2B, respectively. We examined allelic interaction effects of necrosis alleles using simple sequence repeat (SSR) markers in F₂ populations derived from crossing the cultivar “Alsen” with a synthetic hexaploid “TA4152-37”. The SSR marker Xbarc7 was linked at a distance of 3 cM to the quantitative trait loci (QTL) located on chromosome 2B, and Xgwm639 was 11 cM from the 5B QTL. A significant additive by additive epistatic interaction was detected between Ne1 and Ne2 QTL, and the results suggest that Alsen possesses a moderate necrosis allele, Ne2^m; whereas, TA4152-37 possesses a moderate necrosis allele, Ne1^m. The Ne2^m allele had a stronger effect than the Ne1^m allele, and a total of 94.6% of phenotypic variance was explained by these genes and their interactions. This demonstrates the strong phenotypic effect due to even moderate necrosis alleles, and emphasizes the need for breeders to accurately predict and identify hybrids that will result in necrosis.     

Effects of drought stress on concentration of macro- and micro-nutrients in Castor (Ricinus communis L.) plant

This study evaluated effects of drought stress on the concentrations of mineral elements in the leaves of different ecotypes of castor plant. The experimental design was a split-plot randomized complete block with three replications. It was carried out at Fozveh Agricultural Research Station located 20 km from Esfahan, Iran in 2014. The main plot was four levels of water stress (30%, 45%, 60%, and 75% moisture content) and the sub-plot was six castor plant ecotypes (Esfahan, Ardestan, Arak, Naein, Yazd, and Ahwaz). The potassium (K), magnesium (Mg), calcium (Ca), sodium (Na), iron (Fe), copper (Cu), and zinc (Zn) contents were measured and found to be significantly affected by drought stress. Drought stress increased K, Ca and Na contents and decreased Fe, Cu, Zn, and Mg contents of the plants. Various ecotypes of castor plant showed different reactions to drought stress and the Fe concentration varied significantly by the castor plant ecotypes. Interaction between water stress and ecotypes was significant only for Cu and Zn. Understanding the element concentrations under drought stress can be useful for predicting growth and development of castor plants.     

Forms of Reproductive Disorders in Cattle and Buffaloes in Middle Egypt

The objective of this study was to investigate the common forms of reproductive disorders and trends of fertility in cattle and buffaloes in Middle Egypt, and investigate nutritional deficiencies or imbalances as a cause of infertility. During the period from 2003 to 2006 a total of 4276 animals (2755 cattle and 1521 buffaloes) were examined, during winter and summer at three districts of Middle Egypt. Based on the owner complains, animals were categorized as anestrum, repeat breeder and those for pregnancy diagnosis. Feedstuffs of these districts were assessed for nutrient and mineral contents. Animals were examined by rectal palpation and by transrectal ultrasonography. The results showed that, ovarian inactivity was the most common cause of anestrum, whereas endometritis was the main frequent finding of repeat breeding. District, season and year affected the incidences of infertility. The pregnancy rate remained constant (cattle) or increased (buffaloes) from 2003 to 2006. The incidence of ovarian inactivity in both species decreased over the same period. In winter, the commonly used feedstuffs would be adequate to supply the animals with needs, but in summer, rations seem to be deficient in many essential nutrients. In conclusion, ovarian inactivity is the main cause of infertility in cattle and buffaloes in Middle Egypt. There is a link between poor nutrition in summer and the high incidence of ovarian inactivity. Fertility trends during the past few years are encouraging.     

Effect of heat stress on adipokines and some blood metabolites in goats from Jordan

To date and to the best of our knowledge, there have been no available data on the interaction between heat stress (HS) and secretion of adipokines and some blood metabolites in Baladi goats from Jordan. Therefore, this study aimed at evaluating the changes in leptin, adiponectin, non‐ester fatty acid (NEFA) and beta‐hydroxybutyrate (BHB) concentrations in Baladi goats under HS conditions in Jordan. Six goats were exposed to direct solar radiation versus six goats exposed to shade regimen. Blood samples were collected and serum concentrations of leptin, adiponectin, NEFA and BHB were measured. Ambient temperature, relative humidity (RH) and body weight (BW) were recorded. Results indicated that leptin and adiponectin concentrations were significantly increased under HS. The concentration of NEFA was significantly increased under HS at the 7th and 14th days of the experiment, while mean total concentration of NEFA was not significantly affected by HS. Neither weekly nor mean total concentrations of BHB were significantly affected by HS during the experimental period. In conclusion, HS is associated with changes in leptin and adiponectin concentrations in Baladi goats. Heat‐stressed goats were able to keep their blood NEFA and BHB concentrations similar to those of thermo‐neutral goats.