静宁县冬小麦不同覆膜模式的抗旱增产效果研究

[目的]为旱作区冬小麦的大田生产提供科学依据。[方法]采用不同覆膜方式,探讨适合静宁县山旱地冬小麦的最佳栽培模式。[结果]全膜覆土小麦的抗旱效果最为明显,其次为全膜不覆土小麦和膜侧小麦,露地小麦的抗旱效果最差。[结论]全膜覆土小麦的抗旱增产效果明显,可实现多茬栽培,从而降低生产成本,在小麦生产上应大力推广。     

嘉兴市南湖区村级财务规范化建设主要做法及成效

农村财务管理是农村工作的重点与难点。阐述了嘉兴市南湖区开展村级财务规范化管理工作的主要做法,并总结了其取得的成效,以期为嘉兴市南湖区开展村级财务规范化管理工作提供参考。     

Microbial hotspots and hot moments in soil: Concept & review

Soils are the most heterogeneous parts of the biosphere, with an extremely high differentiation of properties and processes within nano- to macroscales. The spatial and temporal heterogeneity of input of labile organics by plants creates microbial hotspots over short periods of time – the hot moments. We define microbial hotspots as small soil volumes with much faster process rates and much more intensive interactions compared to the average soil conditions. Such hotspots are found in the rhizosphere, detritusphere, biopores (including drilosphere) and on aggregate surfaces, but hotspots are frequently of mixed origin. Hot moments are short-term events or sequences of events inducing accelerated process rates as compared to the average rates. Thus, hotspots and hot moments are defined by dynamic characteristics, i.e. by process rates.For this hotspot concept we extensively reviewed and examined the localization and size of hotspots, spatial distribution and visualization approaches, transport of labile C to and from hotspots, lifetime and process intensities, with a special focus on process rates and microbial activities. The fraction of active microorganisms in hotspots is 2–20 times higher than in the bulk soil, and their specific activities (i.e. respiration, microbial growth, mineralization potential, enzyme activities, RNA/DNA ratio) may also be much higher. The duration of hot moments in the rhizosphere is limited and is controlled by the length of the input of labile organics. It can last a few hours up to a few days. In the detritusphere, however, the duration of hot moments is regulated by the output – by decomposition rates of litter – and lasts for weeks and months. Hot moments induce succession in microbial communities and intense intra- and interspecific competition affecting C use efficiency, microbial growth and turnover. The faster turnover and lower C use efficiency in hotspots counterbalances the high C inputs, leading to the absence of strong increases in C stocks. Consequently, the intensification of fluxes is much stronger than the increase of pools. Maintenance of stoichiometric ratios by accelerated microbial growth in hotspots requires additional nutrients (e.g. N and P), causing their microbial mining from soil organic matter, i.e. priming effects. Consequently, priming effects are localized in microbial hotspots and are consequences of hot moments. We estimated the contribution of the hotspots to the whole soil profile and suggested that, irrespective of their volume, the hotspots are mainly responsible for the ecologically relevant processes in soil. By this review, we raised the importance of concepts and ecological theory of distribution and functioning of microorganisms in soil.     

反刍动物饲料组合效应的衡量指标及评估方法综述

反刍动物饲料间的组合效应的衡量指标一般包括:采食量,消化率和生长性能.研究组合效应尚无统一的标准方法,归纳现有的方法,主要可以分为动物试验、体内消化代谢试验和体外试验.三种组合效应的研究方法各有优缺点,我们可以根据试验目的和试验条件来选择合适的方法.本文分别从饲料间的组合效应、衡量指标及其研究方法等方面进行了综述,以供...     

Estimation of direct and social effects of feeding duration in growing pigs using records from automatic feeding stations

Automatic feeding systems in pig production allow for the recording of individual feeding behavior traits, which might be influenced by the social interactions among individuals. This study fitted mixed models to estimate the direct and social effects on visit duration at the feeder of group-housed pigs. The dataset included 74,413 records of each visit duration time (min) event at the automatic feeder from 135 pigs housed in 14 pens. The sequence of visits at the feeder was employed as a proxy for the social interaction between individuals. To estimate animal effects, the direct effect was apportioned to the animal feeding (feeding pig), and the social effect was apportioned to the animal that entered the feeder immediately after the feeding pig left the feeding station (follower). The data were divided into two subsets: “non-immediate replacement” time (NIRT, N = 6,256), where the follower pig occupied the feeder at least 600 s after the feeding pig left the feeder, and “immediate replacement” time (IRT, N= 58,255), where the elapsed time between replacements was less than or equal to 60 s. The marginal posterior distribution of the parameters was obtained by Bayesian method. Using the IRT subset, the posterior mean of the proportion of variance explained by the direct effect (Prpσ^d2) was 18% for all models. The proportion of variance explained by the follower social effect (Prpσ^f2) was 2%, and the residual variance (σ^e2) decreased, suggesting an improved model fit by including the follower effect. Fitting the models with the NIRT subset, the estimate of Prpσ^d2 was 20% but the Prpσ^f2 was almost zero and σ^e2 was identical for all models. For the IRT subset, the predicted best linear unbiased predictor (BLUP) of direct (Direct BLUP) and social (Follower BLUP) random effects on visit duration at the feeder of an animal was calculated. Feeder visit duration time was not correlated with traits, such as weight gain or average feed intake (P > 0.05), whereas for the daily feeder occupation time, the estimated correlation was positive with the Direct BLUP (r^= 0.51, P < 0.05) and negative with the Follower BLUP (r^= −0.26, P < 0.05). The results suggest that the visit duration of an animal at the single-space feeder was influenced by both direct and social effects when the replacement time between visits was less than 1 min. Finally, animals that spent a longer time per day at the feeder seemed to do so by shortening the meal length of the preceding individual at the feeder.     

PGPR接种时期和AM真菌对番茄根结线虫病的影响

作者于温室盆栽条件下研究了植物促生根围细菌(plant growth promoting rhizobacteria,PGPR)Bacillus sp.接种时期和丛枝菌根(arbuscular mycorrhiza AM)真菌摩西球囊霉(Glomus mosseae)接种对番茄(Lycopersicum esculentum Mill)生长发育及根结线虫(Meloidogyne incognitaMi)病的影响。结果表明于番茄播种时接种AM真菌摩西球囊霉+移栽时接种芽孢杆菌(Bacillus sp.)和南方根结线虫(M.incognita)的处理植株发病率和和病情指数最低、防效最高,分别为24.5%、12.5%和70.90%;并且显著增加番茄植株节点数、株高、茎粗、地上部干重及地下部干重。认为播种时接种AM真菌配合移栽时接种PGPR可以显著减轻南方根结线虫对番茄生长发育造成的危害程度,并且对南方根结线虫有较强的抑制效果。     

云南贯众治疗猪蛔虫病疗效观察

考察云南贯众提取化合物山柰酚-3-α-L-（4-O-乙酰基）鼠李糖基-7-α-L-鼠李糖苷的驱除猪蛔虫效果。将自然感染猪蛔虫病猪25头随机分为5组,即贯众化合物高、中、低剂量组,伊维菌素对照组和空白对照组。结果云南贯众提取化合物高、中剂量组驱杀猪蛔虫效果明显,并与伊维菌素组效果相当,具有效果确实可靠、无毒副作用等特点。临床推荐剂量以0.3mg/kg为宜。     

Genetic analysis of mechanisms associated with inheritance of resistance to sheath rot of rice

Understanding genetic mechanisms controlling inheritance of disease resistance traits is essential in breeding investigations targeting development of resistant genotypes. Using North Carolina design II, 32 F₁ hybrids were generated by crossing eight susceptible to four resistant parents and submitted for field evaluation. The analysis of general and specific combining ability (GCA and SCA) indicated involvement of additive and non‐additive gene action controlling inheritance of horizontal resistance to sheath rot of rice. High GCA/SCA ratio and high heritability estimates revealed additive effects and were more predominant than none additive ones. The level of dominance indicated dominant genes was more important than recessive genes. Estimates of GCA and SCA analysis suggested that crop improvement programmes should be directed towards selection of superior parents or good combiners, emphasizing on GCA. As far as source of resistance is concerned, most promising genotypes were Cyicaro, Yunertian and Yunkeng. The predominance of additive genetic effects together with the relevance of dominant genes suggested possibilities of improving the resistance by introgression of resistance genes through recurrent selection coupled with phenotypic selection.     

板蓝根多糖的制备及其对鸡新城疫Lasota疫苗的免疫效果研究

[目的]研究自制的板蓝根多糖对鸡新城疫弱毒疫苗的免疫效果.[方法]将120只健康从肉仔鸡随机分为板蓝根多糖组、黄芪多糖组以及生理盐水对照组,研究板蓝根多糖对鸡新城疫Lasota疫苗的免疫增强作用.[结果]板蓝根多糖组和黄芪多糖组鸡NDV血凝抑制抗体滴度差异不显著,而板蓝根多糖组和黄芪多糖组鸡的免疫器官指数都显著高于生理盐水对照组.[结论]制备的板蓝根多糖可以用作鸡新城疫弱毒疫苗的免疫增强剂.     

红松、蒙古栎和色木槭凋落物混合分解研究

以位于中国东北吉林蛟河的天然红松阔叶林森林生态系统为研究对象,针对其中主要树种的凋落物分解速 率和分解过程研究中的几个关键问题进行了探讨。研究内容包括该生态系统中常见的红松、蒙古栎和色木槭的凋 落物的分解速率,在分解过程中的养分动态和凋落物的混合效应及其机制等。本研究使用的具体方法为凋落物降 解袋法。结果表明:1)凋落物中各种营养元素的初始含量差异显著,其中初始氮、磷含量与凋落物的分解速率呈正 相关。2)不同树种凋落物的失重率之间差异显著,且均随时间进程增大,但是和时间不成线性关系。3)在整个分 解进程中,凋落物的分解速率开始时明显升高,中后期以后逐渐平稳。4)单一凋落物分解中,阔叶凋落物的分解速 率高于针叶的分解速率。5)395 d 的分解进程中,有机碳(C)、全氮(N)、全磷(P)、全钾(K)含量呈动态变化, N 和 P 均表现出富集现象,N 在短期富集后强烈释放;C 和K 表现为净释放;C/ N 持续下降。6)红松 蒙古栎和红松 色 木槭混合凋落物对分解速率产生显著的混合效应; 混合凋落物对分解过程中的养分动态, 尤其是P 和N 元素具有 显著的混合效应, 而混合效应的方向(正或负)和强度是十分复杂的;混合效应是否能发生及其发生的方向主要是 由组分凋落物的特点来决定的。