Assessing the effect of administering probiotics in water or as a feed supplement on broiler performance and immune response

1.?Two routes of probiotic administration in broiler farms, in water and in feed, were compared using 360 one-day-old male broiler chickens. Controls received no probiotics or antimicrobials. The water group received a probiotic preparation at a rate of 0·5 g/l, and the feed group received it at an inclusion rate of 1 g/kg.

2.?Performance of broilers in terms body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR) improved when probiotic was provided via drinking water, compared to the control and feed groups. Probiotic administration reduced plasma cholesterol and triglyceride concentrations.

3.?Spleen (28 and 42 d) and bursa (42 d) relative weights were influenced by method of probiotic administration, which also improved T-cell dependent skin thickness response to phytohaemagglutinin (PHA) injection. The effect of challenge by dinitrochlorobenzene (DNCB) depended on the method of probiotic administration.

4.?The method of probiotic administration can influence the performance and immune competence of birds, and administration via drinking water appears to be superior to the more conventional in-feed supplementation method.     

Chemical control of Apriona germari （Hope） larvae with zinc phosphide sticks

Larvae of Apriona germari(Hope),found widely in China,cause serious damage to trees and are difficult to control.Since some biological control methods have not been applied effectively in the field,chemical control methods are used widely.Because of low cost,no poisonous residues and relatively safe application,zinc phosphide sticks have been tested to control the larvae as a matter of urgency.However,there were no criteria about the dosage and use.Given the characteristics of larvae tunnels on triploid Pop...     

Salinity effects on nitrogen metabolism in plants – focusing on the activities of nitrogen metabolizing enzymes: A review

Nitrogen (N) metabolism is of great economic importance because it provides proteins and nucleic acids which in turn control many cellular activities in plants. Salinity affects different steps of N metabolism including N uptake, NO₃^? reduction, and NH₄⁺ assimilation, leading to a severe decline in crop yield. Major mechanisms of salinity effects on N metabolism are salinity-induced reductions in water availability and absorption, disruption of root membrane integrity, an inhibition of NO₃^? uptake by Cl^?, low NO₃^? loading into root xylem, alteration in the activities of N assimilating enzymes, decrease in transpiration, and reduction in relative growth rate which results in a lower N demand. However, the effects of salinity on N metabolism are multifaceted and may vary depending on many plant and soil factors. The present review deals with salinity effects on N metabolism in plants, emphasizing on the activities of N metabolizing enzymes in a saline environment.     

Changes in the Degree of Contamination of Organic Horizons of Al–Fe-Humus Podzols upon a Decrease in Aerotechnogenic Loads,the Kola Peninsula

Contamination levels of the organic horizon of Al–Fe-humus podzols (Albic Rustic Podzols) in the zone affected by atmospheric emissions of the Severonikel smelter (Murmansk oblast) within a 20-yearlong period are compared. The spatiotemporal changes in the total content of heavy metals in the soils in response to a decrease in aerotechnogenic loads have a complicated pattern. As the content of heavy metals in the soils varies widely, the correlation between their amount in the organic soil horizon and the distance from the contamination source is absent. In response to the ninefold decrease in the amount of atmospheric emission of Ni compounds, the bulk content of Ni in the organic horizons of podzols reliably decreased by 2.5 times. The threefold decrease in the emission of Cu compounds proved to be insufficient for a significant decrease in the Cu content in the soils. In 2016, the content of heavy metals in some sampling points even increased in comparison with the earlier periods. The Ni-to-Cu ratio in the soil samples changed significantly. In 1989–1994, bulk forms of heavy metals in the soil samples formed the sequence Ni > Cu > Co; in 2016, it changed to Cu > Ni > Co, which corresponds to the proportions of these metals in the aerial emissions. Under conditions of the continuous input of heavy metals from the atmosphere, the contamination of the organic horizons of podzols with heavy metals remains at the high or very high levels.     

DGT和化学提取法评价贵州赫章土法炼锌区污染土壤中镉的植物吸收有效性

以马铃薯、白菜和玉米为典型作物,以贵州省赫章县"土法炼锌"冶炼区重金属复合污染土壤为供试土壤,通过盆栽试验比较了五种传统化学提取剂(HNO_3、DTPA、LMWOAs、HCl和CaCl_2)和梯度扩散薄膜技术(diffusive gradients in thin films,DGT)对土壤Cd的植物吸收有效性影响。研究结果表明:"土法炼锌"影响区土壤总体呈碱性;马铃薯与白菜可食部位对供试土壤Cd的富集系数基本相同,而玉米籽粒对供试土壤Cd的富集系数远小于块茎类和叶菜类,马铃薯、白菜和玉米的富集系数平均值分别为0.105 3、0.105 8和0.007 9;一元线性与二元回归表明DGT测定土壤有效Cd含量与作物可食部分Cd含量相关系数大于五种传统化学提取剂;五种提取态中,CaCl_2提取态测定有效态Cd也可较好预测马铃薯和白菜可食部分Cd含量(R2adj分别为0.805和0.808),HNO_3提取态测定有效态Cd也可较好预测三种作物可食部分Cd含量(R_(adj)~2分别为0.822、0.874和0.764)。在本实验条件下,DGT技术评价"土法炼锌"冶炼区土壤镉植物吸收有效性效果优于五种化学提取态,但考虑不同作物类型,土壤pH因素以及操作的简单快捷性,CaCl_2提取态和HNO_3提取态也可成为预测重金属冶炼区复合污染碱性土壤Cd的植物吸收有效性的方法。     

Ecological assessment of soils in high-mountain landscapes of northeastern part of the Greater Caucasus (Azerbaijan)

The current state of soils and bioproductivity of high-mountain pastures and hayfields in the northeastern part of Great Caucasus within Azerbaijan were studied, and the quality assessment of soils was performed. The ecological evaluation of soils was based on special assessment scales and soil bonitet scores. The soils suitable for the development of meadow vegetation were identified. The highest score (89 points) was given to mountainous meadow chernozemlike soils (Eutric Mollic Leptosols); these soils are most suitable for pasturing. Mountainous meadow soddy soils (Dystric Umbric Leptosols) ranked second (76 points). Mountainous meadow-steppe soils (Eutric Mollic Leptosols) were estimated at 72 points; these soils are suitable for plant communities of subalpine meadows. Mountainous meadow soddy–peaty soils (Brunic Umbric Leptosols) had the lowest score of 68 points mostly because of the excessive precipitation against the background of relatively low mean annual temperature limiting the biological productivity of alpine meadows.     

植物表观遗传变异

表观遗传变异是一种不涉及DNA序列的改变但可以通过有丝分裂和（或）减数分裂实现代间传递的变异,主要包括组蛋白修饰、DNA甲基化和miRNA。本文分别对植物中这三种变异类型的特征、作用机制、功能及研究方法等进行了综述。其中组蛋白修饰包括乙酰化、甲基化和磷酸化等。不同组蛋白修饰方式之间的相互作用可能对植物细胞内的重要事件起决定作用,如种子的萌发、开花以及对环境的应答等。组蛋白修饰的主要研究方法为ChIP-on-chip和GMAT。DNA甲基化作为基因表达的一种调控机制,在植物生长发育过程中具有重要作用。DNA甲基化程度与基因表达活性之间存在负相关性,DNA甲基化程度越低,基因表达活性越高;反之,则越低。DNA甲基化研究方法主要包括MSAP法、McCOBRA和MS-DBA等;植物miRNA序列在进化上高度保守,主要调控植物形态建成,尤其是花的发育。其研究方法涵盖了miRNA的鉴定、表达分析和功能研究。此外,不同植物表观遗传变异之间相互调控,构成了一个完整的表观遗传调控网络。     

两个甜瓜品种对白粉病菌的抗性遗传分析

在空调温室，利用风媒接种方法研究了2个甜瓜品种PI414723和宁甜1号对北京的1个白粉病菌系的抗性遗传。结果表明，这2个品种对该菌系的抗性均由1对不完全显性抗病基因控制。等位性测验表明，这2个品种携带的抗病基因为同一基因或彼此间为等位基因。