Fungistasis and general soil biostasis - A new synthesis

In most soils, fungal propagules are restricted to a certain extent in their ability to grow or germinate. This phenomenon, known as soil fungistasis, has received considerable attention for more than five decades, mostly due to its association with the general suppression of soil-borne fungal diseases. Here, we review major breakthroughs in understanding the mechanisms of fungistasis. Integration of older fungistasis research and more recent findings from different biological and chemical disciplines has lead to the consensus opinion that fungistasis is most likely caused by a combination of microbial activities, namely withdrawal of nutrients from fungal propagules and production of fungistatic compounds. In addition, recent findings indicate that there are mechanistic links between these activities leading towards an integrated theory of fungistasis. Among the potentially fungistatic compounds volatiles have received particular attention. Whereas it has long been assumed that fungistasis is the result of the metabolic activity of the total soil microbial biomass, more recent research points at the importance of activities of specific components of the microbial community. These insights into fungistasis have also formed the basis for strategies to increase general soil suppression. Besides these basic and practical aspects of fungistasis, its impact on fungal ecology, in particular on fungal exploration strategies, is discussed. Finally, we take a closer look at plant-soil feedback experiments to demonstrate the occurrence of fungistasis-like phenomena and to suggest that fungistasis may be part of a much wider phenomenon: general soil biostasis.     

重庆市三峡库区柑橘渣的营养物质和苦味物质研究

本文对重庆市三峡库区柑橘渣的营养物质和苦味物质含量进行了系统检测。结果表明,重庆市三峡库区的柑橘渣无氮浸出物、消化能和钙含量较高,氨基酸组成全面,但粗蛋白质和总磷含量低,水分、粗纤维和苦味物质含量高,作为潜在的饲料资源,经过适当处理可以大量开发作畜禽饲料。     

育苗移栽对麦套棉~（14）CO_2同化量及运转分配的影响

运用１４Ｃ示综技术，研究了营养钵育苗移栽对麦套棉１４Ｃ同化物生产、运转分配及其再分配的影响。试验结果表明，营养钵育苗移栽不仅使棉株在苗期、蕾期、花铃期的１４Ｃ同化量显著提高，而且对各期同化产物向子棉的再动员具有明显的促进作用。各期标记后３天的测定结果显示，育苗移栽增加棉苗同化物质向根系和茎中的分配，而减少向顶芽的分配，这有利于促根壮苗；蕾期同化物质向顶芽和边心的分配比例下降，这有利于控制棉花的营养生长，防止或减轻茎枝旺长，实现健壮稳长，促进花芽分化；育苗移栽在花铃期的效果表现为，促使更高比例的同化物质向生殖器官（特别是成铃）中分配，因而有利于蕾铃发育。上述影响的综合在现是单位面积上的铃数、单铃重、衣分和皮棉产量显著提高。     

农药助壮素电极的研制

研制成以四间甲苯硼酸钾为活性载体的农药助壮素选择性电极。该电极在ｐＨ４．５￣９．５的１０＾－２ｍｏｌ／Ｌ氯化锂水溶液中，测定助壮素的线性响应范围为１．２×１０＾－２￣７．５×１０＾－６ｍｏｌ／Ｌ，斜率为５４．０，检测下限为１．４×１０＾－６ｍｏｌ／Ｌ。电极性能良好，适用于助壮素的快速分析。     

4-氨基安替比林分光光度法测定土壤中的挥发酚

该文主要研究了4-氨基安替比林分光光度法测定土壤中的挥发酚的方法,并对该方法的检出限、精密度、加标回收率、线性进行了验证。结果表明,该方法的线性相关可达到0.999以上,精密度在7%以内,检出限为0.011mg/kg,加标回收率在89%～105%。     

不同装烟方式对烟叶色泽·酚类物质及抗氧化能力的影响

[目的]考察不同装烟方式对烟叶品质的影响。[方法]采用烟篦、烟夹和烟筐3种装烟方式进行烤烟,对烟叶的色泽、酚类物质和抗氧化能力进行了比较研究。[结果]研究表明,烟夹和烟篦装烟方式下的烟叶L*、a*、b*值均高于烟筐烤烟,3种装烟方式的烟叶a*、b*值之间没有显著性的差异,L*值则有显著性差异(P0.05),h值中烟夹和烟筐装烟方式显著低于烟篦装烟。烟篦烤烟的总酚、绿原酸含量最高,烟夹烤烟次之,烟筐烤烟的最低,且有显著性的差异(P0.05),而芸香苷含量差别不大。3种装烟方式的抗氧化能力顺序(DPPH自由基清除能力和还原能力)为烟篦烟夹烟筐,且与总酚含量和绿原酸含量之间存在一定的正相关性。[结论]从烟叶品质和抗氧化能力考虑,3种装烟方式中,烟篦装烟是比较好的选择。     

Analysis of Noxious Gas Pollution in Horse Stable Air

The aim of this study was to determine quantitative and qualitative occurrence of noxious gas compounds in the stable, depending on the time of the day (4:00 AM, 12:00, 8:00 PM), the height (20 cm, 150 cm), and the place (boxes, aisle) from which the samples were collected. Seven compounds were analyzed (NH₃, SO₂, COS, HCN, CH₄, NO₂, and CO). For analyzing stable air, a mobile gas analyzer was used. The time of day was a significant differential factor (P < .01) for concentrations of NH₃, COS, and CH₄. The highest concentrations of CH₄, COS, NO₂, NH_3, and CO appeared at 4:00. For the rest of the studied compounds (SO₂, HCN, CO) differences were not statistically significant, but there was a tendency for the highest concentrations at 12:00. The concentrations of gas compounds depending on height did not differ significantly from each other, but there was a tendency for higher concentrations of NH₃, SO₂, CH₄, and CO at 150 cm and for HCN at 20 cm. COS and NO₂ remained constant at both heights in boxes. The places where the samples were collected was a significant differential factor (P < .01) for NH₃ and SO₂. For the rest of the studied compounds the differences were not statistically significant. It can be concluded that many noxious compounds may appear without being noticed, and that is why it is necessary to provide stables with efficient air exchange throughout the day.     

贻贝（Mytilus）在贮藏过程中气味的变化

本文通过动态顶空法分离提取了贻贝干品的挥发性物质，通过气相色谱──质谱鉴定出了７４个化合物。其中包括２０个醛酮类化合物，１３个醇类化合物，３０个碳氢化合物及数个杂环化合物。羰基化合物如 １，５－辛二烯－３－酮、３，５－辛二烯－２－酮，醇类化合物如辛烯－１－醇、３，６－壬二烯－１－醇均为脂肪氧化产物。普通包装和真空包装样品气味差别主要在于高挥发性组分。     

不同瓤色小型西瓜成熟果实挥发性风味物质GC-MS分析

采用顶空固相微萃取(HS-SPME)和气相色谱质谱联用技术(GC-MS)分析黄瓤色、粉红瓤色和大红瓤色的不同瓤色西瓜品种成熟果实中挥发性的风味物质。结果表明:(1)不同瓤色西瓜共鉴定出76种挥发性风味物质,其中包括23种醛类、15种醇类、9种烯类、10种酮类、6种酯类,这5类物质占测定挥发性风味物质总数的82.9%,相对含量占总峰面积的87.42%～91.43%,为西瓜果实中的主要挥发性风味物质成分;(2)两个黄瓤色西瓜品种的酯类物质和稀类物质明显高于两个粉红瓤和大红瓤色西瓜品种,而酮类物质明显低于粉红瓤和大红瓤色西瓜品种。(3)3种不同瓤色西瓜品种间挥发性风味物质种类和含量均存在显著差异,可作为区分不同西瓜品种的重要参考指标及西瓜品质育种依据之一。     

测定珍珠粉总卟啉成分的荧光光谱法

珍珠是传统名贵中药,具有镇心安神、养阴熄风、清热解毒、明目去翳等功效。自八十年代以来,国内有多家单位进行了珍珠综合利用的研究,取得了一定的进展(门摩西,1989年)。实验研究证实珍珠粉能明显抑制小鼠自发活动,抑制家兔大脑皮层的活动,并显著改变脑内单胺类神经递质的含量,具有中枢抑制作用。此外,作者(1988年)观察到珍珠粉能明显延长家蚕和小鼠寿命,降低小鼠心肌和脑