香菇杂菌绿色木霉室内抑制试验初探

为寻求控制绿色木霉等杂菌的有效途径和减少农药对环境的污染 ,采用多菌灵、甲基托布津和多种药用植物水煎剂 ,对香菇栽培中重要污染菌绿色木霉进行了室内抑制试验。绿色木霉对多菌灵和甲基托布津很敏感 ,在 0 5mg L的低浓度下仍能被抑制 ,而在该浓度下 ,多菌灵对香菇菌丝生长影响较小。在被试验的 2 0余种药用植物中 ,有 6种药用植物对绿色木霉有较明显的抑制作用 ,其中以黄檗水煎剂的抑菌效果最佳     

利用响应面分析法优化向日葵盘中果胶的提取工艺

利用响应面试验设计考察提取温度、提取时间、料液比和pH值几因素对果胶得率的影响。研究结果发现,提取时间、温度和pH值对提取率有显著影响,向日葵盘果胶的最佳提取条件为提取温度79℃、提取时间80min、料液比0．04、pH值3．20。向日葵盘果胶最大得率为10．44％。     

Characterization of cytoplasmic male sterility in Petunia hybrida. I. Localization,composition and activity of esterases

Summary Anthers of male fertile, cytosterile and restored male fertile clones of Petunia hybrida were compared for esterase activity and composition in subsequent stages of microsporogenesis. Three methods were applied (i) ultra-thin layer isoelectric focussing on polyacryl amide gels, (ii) quantitative spectrophotometrical assay, (iii) histochemical determination of total esterase activity associated to the azo-coupling method (Pearse, 1972).In male fertile and restorer idiotypes the isozyme patterns were quite similar. Both the number and intensity of bands increased gradually till the tetrad stage. In contrast, esterase activity in cytosterile anthers remained at a low level and hardy any new bands showed up in later stages. This unvariable, low activity level in cytosterile anthers was also found in the spectrophotometric assay. Histochemical determinations revealed that in male fertile anthers esterase activity is concentrated in the outer tapetal layer at late prophase and that it accumulates there till the early microspore stage. In male sterile anthers esterase accumulation in the tapetal cells stops at the moment that tapetal breakdown becomes visible. This suggests that differences in esterase activity and composition are an effect rather than a cause of the failing pollen formation.     

Species affinities between Cajanus cajan and some Atylosia species based on esterase isoenzymes

Summary Esterase isozymes were studied in seed extracts of Cajanus cajan and six Atylosia species by polyacrylamide gel electrophoresis and isoelectrofocusing. The isozyme patterns were stable and accession specific. Within the accessions of the Atylosia species, A. albicans and A. scarabaeoides showed three common bands indicating that they are more closely related to each other than to the other species. Of the accessions of Atylosia only A. cajanifolia shares the esterase isozyme of C. cajan and hence seems to be the closest wild relative of C. cajan.     

响应面法优化籽瓜皮果胶提取工艺

以籽瓜皮为原料,采用响应面法,应用Box-Behnken方法建立数学模型,对其果胶超声波辅助酸法提取工艺进行优化。结果表明,影响籽瓜皮果胶得率各因素的主次顺序为:浸提温度超声功率p H超声时间;采用超声波辅助酸提法提取籽瓜皮果胶的最佳工艺参数为:液料比50∶1(m L/g),p H 1.9,超声功率140 W,浸提温度67℃,超声时间54 min。在此条件下籽瓜皮果胶得率的理论值为13.85%,验证试验的果胶得率为13.58%,二者接近,表明该数学模型优化的籽瓜皮果胶提取工艺是可行的;采用超声波辅助酸法提取籽瓜皮果胶,可比传统的酸提取法节省时间40%以上。     

柑橘果实发育中果胶酸钙、草酸钙和果胶动态的研究

以单性结实的龟井蜜柑和自花结实的鄂柑1号橘为试材,对整个果实发育期的子房(幼果)、果皮和果肉的果胶酸钙、草酸钙和果胶含量变化进行了测定。结果表明,1)两品种子房(幼果)果胶酸钙含量呈类似的下降趋势;草酸钙则相反,龟井花后趋下降,而鄂柑1号却明显上升;而且鄂柑1号子房(幼果)果胶酸钙、草酸钙和果胶含量均相对较高。2)在果实增大期内,两品种果皮和果肉的果胶酸钙含量均出现显著上升,对应果皮草酸钙含量虽有波动但居相对较高水平,而果肉草酸钙则趋明显下降。3)两品种果皮和果肉水溶性果胶含量均在增大期内呈显著上升,对应原果胶含量均相对较高,进入增大后期均明显下降。     

茶油皂脚脂肪酸甲酯制备的水溶性改性胺固化物性能研究

以茶油皂脚脂肪酸甲酯制备的水溶性改性胺(CA-921)与水性环氧树脂固化,通过热重分析、差示扫描量热法(DSC)、机械性能测试及扫描电镜分析,研究了环氧树脂分散相粒子的粒径和黏度、环氧基与胺氢物质的量之比及固化温度对固化物性能的影响.研究结果表明,黏度及粒径均较小的水性环氧乳液AB-EP-20与固化剂CA-921复配所...     

微波-超临界CO_2萃取联用萃取柚皮果胶工艺研究

采用超临界CO2萃取与微波处理技术相结合萃取柚皮果胶,探讨了微波辐射功率、萃取时间、萃取压力、萃取温度、CO2流量对柚皮果胶得率的影响,并采用正交试验对实验方案进行优化。研究结果表明:当原料用量5 g、微波辐射功率450 W、萃取时间15 min、萃取压力8.5 MPa、萃取温度40℃和CO2流量12 L/h时,果胶的平均得率22.63%,比相同条件下微波辅助水浴加热提取法的果胶得率高6.52个百分点。     

Ten-year response of the herbaceous layer to an operational herbicide-shelterwood treatment in a northern hardwood forest

Shelterwood seed cutting in conjunction with herbicide site preparation has proven effective at regenerating Allegheny hardwood forests, but the long-term impact of this silvicultural system on herbaceous vegetation has not been determined. From 1994 to 2004, we studied the impacts of operational herbicide site preparation using glyphosate plus sulfometuron methyl herbicides in the context of a shelterwood seed cut. Our study took place on 10 partially cut sites on the Allegheny National Forest in northwestern Pennsylvania. Half of each site received herbicide and half did not in a split-plot design with repeated measures. Fences were erected after year six because deer impact had increased. Resilience of individual species and the community were determined using measures of percent cover by species or species groups and indices of diversity and similarity comparing post-treatment to pre-treatment conditions and controls. In the short term, abundance of all species was reduced and there were four fewer species on average in treated areas. No species was eliminated by herbicide across all sites in the long term. Graminoids were more abundant on treated plots after year six. Targeted ferns remained less abundant on treated than control plots after 10 years. Species richness recovered within 4 years following treatment. Shannon Diversity and Shannon Evenness were greater in treated than in control plots over the full study period, but the differences were not significant in any single year. The richness-based Jaccard index of similarity did not differ between control and treatment plots after year two, while relative abundance influenced indices showed significant differences through year eight. Results suggest that herbaceous layer vegetation is resilient to the disturbance created by herbicide-shelterwood treatments.     

小麦根尖细胞壁对铝的吸附/解吸特性及其与耐铝性的关系

研究了耐铝性明显差异的2个小麦基因型西矮麦1号(耐性)和辐84系(敏感)根系对铝毒胁迫的反应与根尖细胞壁组分以及细胞壁对铝的吸附和解吸的关系。结果表明,30mol/L.AlCl3可迅速抑制小麦根系伸长,但对辐84系根系伸长的抑制更为明显,且小麦根系相对伸长率随着铝浓度的提高而急剧降低。在30mol/L.AlCl3处理24h后,西矮麦1号根系伸长的抑制率为33.3%,而辐84系根系伸长的抑制率高达70.9%。小麦距根尖0～10.mm根段的铝含量和细胞壁中果胶糖醛酸含量显著高于10～20.mm根段,且前者对铝的累积吸附量明显大于后者;在0～10.mm根段,敏感基因型果胶含量高于耐性基因型,其根尖含铝量及根尖细胞壁对铝的吸附量都要大于后者。采用1.0.mol/L.NH3.H2O对细胞壁预处理2.h降低果胶甲基酯化程度后,耐性和敏感基因型根尖细胞壁对铝的累积吸附量分别降低了17.1%和20.9%,但对铝的累积解吸率没有影响。由此可见,小麦根尖是铝毒的主要位点,细胞壁果胶含量和果胶甲基酯化程度可能是导致不同小麦基因型根尖细胞壁对铝吸附量、铝积累量的差异及其对铝毒胁迫反应的差异的重要原因。