饲用酵母甘露聚糖检测方法研究进展

酵母细胞中的甘露聚糖是一种非淀粉多糖,存在于酵母细胞壁的外层中。酵母甘露聚糖通常与蛋白质以共价键的形式相连,被称为甘露糖蛋白。酵母甘露聚糖在动物营养中具有重要的生物学功能,是酵母源生物产品中的关键功能性成分之一。甘露聚糖含量是评价酵母提取物、酵母水解物、酵母培养物等产品品质的重要指标。本文就饲用酵母甘露聚糖的检测方法研究进展做一综述。     

优化提取裸花紫珠总黄酮含量及对表皮伤口易感染菌抑菌性的研究

为了选出裸花紫珠总黄酮提取的最优方法,比较了ASE、超声、微波萃取和多功能浓缩4种提取方法在裸花紫珠总黄酮提取率上的差异,并利用微孔刃天青法测定总黄酮对表皮易感染菌的MIC值。结果发现ASE法总黄酮提取率最高,约为1.26%,其次为超声和微波萃取法,总黄酮提取率分别约为1.03%和0.98%,多功能浓缩法提取率最低,约为0.36%,且耗时最长。而且研究发现,ASE的MIC值最低。最终得出ASE提取效率最高,且提取物有较好的抑菌性,是裸花紫珠总黄酮提取的最优方法。     

槟榔黄化病病原及检测方法研究进展

黄化病是一种严重威胁槟榔生产种植的毁灭性传染性病害，目前主要在印度和我国槟榔主产区发生。本文从非生物与生物因素两方面对槟榔黄化病病原认识过程及检测方法进行详细的综述。     

A stochastic surplus production model in continuous time

Surplus production modelling has a long history as a method for managing data‐limited fish stocks. Recent advancements have cast surplus production models as state‐space models that separate random variability of stock dynamics from error in observed indices of biomass. We present a stochastic surplus production model in continuous time (SPiCT), which in addition to stock dynamics also models the dynamics of the fisheries. This enables error in the catch process to be reflected in the uncertainty of estimated model parameters and management quantities. Benefits of the continuous‐time state‐space model formulation include the ability to provide estimates of exploitable biomass and fishing mortality at any point in time from data sampled at arbitrary and possibly irregular intervals. We show in a simulation that the ability to analyse subannual data can increase the effective sample size and improve estimation of reference points relative to discrete‐time analysis of aggregated annual data. Finally, subannual data from five North Sea stocks are analysed with particular focus on using residual analysis to diagnose model insufficiencies and identify necessary model extensions such as robust estimation and incorporation of seasonality. We argue that including all known sources of uncertainty, propagation of that uncertainty to reference points and checking of model assumptions using residuals are critical prerequisites to rigorous fish stock management based on surplus production models.     

Revisiting rice breeding methods – evaluating the use of rapid generation advance (RGA) for routine rice breeding

Rice production needs to increase in the future in order to meet increasing demands. The development of new improved and higher yielding varieties more quickly will be needed to meet this demand. However, most rice breeding programmes in the world have not changed in several decades. In this article, we revisit the evidence in favour of using rapid generation advance (RGA) as a routine breeding method. We describe preliminary activities at the International Rice Research Institute (IRRI) to re-establish RGA on a large scale as the main breeding method for irrigated rice breeding. We also describe experiences from the early adoption at the Bangladesh Rice Research Institute. Evaluation of RGA breeding lines at IRRI for yield, flowering time and plant height indicated transgressive segregation for all traits. Some RGA lines were also higher yielding than the check varieties. The cost advantages of using RGA compared to the pedigree method were also empirically determined by performing an economic analysis. This indicated that RGA is several times more cost effective and advantages will be realized after 1 year even if facilities need to be built. Based on our experience, and previous independent research empirically testing the RGA method in rice, we recommend that this method should be implemented for routine rice breeding in order to improve breeding efficiency.     

饲料中无机元素分析方法研究进展

饲料中所含的无机元素对动物生长具有重要意义。在饲料中过量添加无机元素会导致环境污染问题,也会通过食物链最终危害消费者的身体健康,因此,对饲料产品中的无机元素进行检测和动态监控尤为重要。综述了近年来饲料中无机元素含量检测主要应用的前处理方法及其含量检测技术,分析了不同前处理方法和含量检测技术的优点和不足,以期为饲料中无机元素分析方法的科学、合理应用提供参考。     

实木家具的拆装式结构实现路径探究

遵循结构合理、体积缩小、组装方便、外形美观的设计原则,从拆装式节点实现形式、整体结构拆装方式二个维度系统阐述了实木家具拆装结构实现路径,并对榫自锁可拆式、连接件可拆式两种实木家具拆装式节点形式及椅类、桌台类、柜类、床类家具的整体结构可拆装方式进行了详细介绍,以期为实木家具的结构优化及平板化包装提供思路。     

耕作方式及秸秆还田对土壤性质、微生物碳源代谢及小麦产量的影响

以小麦品种济麦22为试验材料,采用裂区试验设计,耕作方式为主区,分别设常规翻耕(C)、深松(S)、旋耕(R)处理,副区为秸秆还田量,分别设秸秆全还田(P)和秸秆不还田(A)处理,采用Biolog Eco技术测定土壤微生物碳源代谢功能,并分析土壤基本理化性质和作物产量。结果显示:深松与秸秆还田均有利于土壤含水量和有机碳含量的提高,0～15 cm土层分别提高了9.78%和24.00%,15～30 cm土层分别提高了7.08%和15.81%;深松提高了15～30 cm土层的pH值6.67%,秸秆还田提高了0～15 cm土层的pH值4.32%。深松和秸秆还田均有利于代谢多样性(丰富度指数、香浓多样性指数)、碳源代谢强度的提高,0～15 cm土层分别提高了26.84%、3.84%和38.02%,15～30 cm土层分别提高了11.87%、 3.63%和14.74%。主成分分析表明常规翻耕秸秆不还田和旋耕耕作秸秆不还田碳源代谢功能相近,15～30 cm层次内常规翻耕秸秆全还田碳源代谢功能和深松耕作秸秆全还田处理相近。深松和秸秆还田平均提高了小麦产量5.82%,微生物碳源代谢功能与小麦产量具有极显著的相关性。     

基于稳定同位素的上海地产蔬菜种植模式及产地判别

为保护蔬菜的优质优价及质量安全,以上海9个农业产区(宝山区、崇明区、奉贤区、嘉定区、金山区、闵行区、浦东新区、青浦区和松江区)蔬菜为研究对象,分析不同产区蔬菜的δ¹⁵N值差异及其对种植模式(常规、绿色或有机种植)的指示;对δ¹³C、δ¹⁵N、δ²H和δ¹⁸O值进行单因素方差分析,并应用主成分分析(PCA)、偏最小二乘判别分析(PLS-DA)及支持向量机(SVM)方法,建立上海地产蔬菜产地判别模型。结果表明,宝山区、松江区和嘉定区蔬菜的δ¹⁵N值占前三,且分别与δ¹⁵N值最低的浦东新区蔬菜(4.44‰)存在显著差异,且仅有浦东新区蔬菜可能为绿色或有机种植的比例低于50%;δ¹³C、δ²H和δ¹⁸O值只在部分产区间差异显著,PCA可初步实现浦东新区蔬菜与其他8个产区的鉴别;PLS-DA最优模型可以很好地实现浦东新区蔬菜产地判别(预测准确率为98.80%),SVM最优模型可以很好地实现宝山区(预测正确率96.38%)、嘉定区(预测正确率92.77%)和青浦区(预测正确率91.57%)蔬菜的产地判别,SVM最优模型可以较好地实现金山区、松江区、崇明区和奉贤区蔬菜的产地判别。本研究结果为上海地产蔬菜种植模式及产地判别提供了参考方法,并为其溯源和质量安全保护提供了基础数据。     

3种水质调控方式下刺参池塘初级生产力的周年变化

通过对自然纳潮、微孔曝气、养水机池塘不同水层初级生产力及其相关参数的研究,分析养水机对初级生产力的影响。结果表明,3种水质调控方式池塘,初级生产力年均值、P/R值均以养水机池塘最高,微孔曝气池塘次之,自然纳潮池塘最低。养水机池塘、微孔曝气池塘、自然纳潮池塘的初级生产力年均值分别为(6.22±0.54)、(5.37±0.60)、(4.69±0.53) gO_2/(m~2·d)。3种水质调控方式下,养水机池塘30～50 cm水层和50～100cm水层初级生产力差异不显著,而微孔曝气池塘和自然纳潮池塘这两水层之间初级生产力差异显著,且养水机池塘50～100 cm的水层初级生产力显著高于微孔曝气和自然纳潮池塘。研究表明,养水机能显著提高刺参池塘50 cm以下水层的初级生产力,缩小上层和下层初级生产力之间的差距,从而提高池塘水体总初级生产力,为刺参饵料和池塘物质快速循环提供基本保障。