响应面优化绿穗苋多糖的提取工艺

本研究旨在对热水工艺提取绿穗苋多糖的条件进行优化。在单因素实验基础上,筛选得到三个主要对绿穗苋多糖提取率相关的因素,其分别为:提取料液比、提取时间和提取温度。采用响应面试验设计软件,以提取料液比、提取时间和提取温度3因素作为试验的自变量,绿穗苋多糖提取率作为因变量,运用Box-Behnken实验设计和响应面分析法,得到了热水提取绿穗苋多糖工艺的最佳条件:料液比1:42.08(g/mL),提取温度92.30℃,提取时间219.01 min有最大多糖提取率。提取率为16.68%,与试验模型预测提取率为16.81%相近。本研究对绿穗苋多糖提取优化的研究为进一步探讨绿穗苋多糖生物活性的的研究提供了材料基础。     

响应面法优化微波辅助提取发酵虫草菌丝体多糖工艺

为优化发酵虫草菌粉多糖的微波辅助提取工艺,在单因素实验基础上,以液固比、微波功率以及提取时间为自变量,多糖提取率为响应值,采用中心组合设计的方法,研究各自变量及其交互作用对多糖提取率的影响。利用SAS软件和响应面分析相结合的方法对发酵虫草菌粉多糖的微波辅助提取工艺进行优化,确定了微波辅助提取多糖的最佳条件：液固比值12．2,微波功率650．5W,提取时间11．8min,在此条件下,多糖提取率达到6．41％。采用此法提取的虫草菌丝体多糖,当质量浓度为1mg／mL时,对二苯代苦味肼基自由基（DPPH）清除率达到76％。     

微波法提取楮实子多糖的工艺研究

采用单因素试验和正交试验,对微波法提取楮实子多糖的工艺进行研究,得到了最佳工艺条件:料液比1∶15,微波处理时间12 min,微波功率450 w,浸泡时间180min.在此条件下,楮实子多糖的提取率为8.79％.     

两种方法提取香菇多糖的比较研究

采用正交试验比较研究热水浸提法和微波提取法提取香菇多糖。热水浸提法的最佳工艺为:提取温度70℃、提取时间4h、料液比1∶15,提取率3.243%;微波提取法的最佳工艺为:微波功率560W、微波处理时间60s、料液比1∶10,提取率4.771%。微波提取法效率高、时间短,是理想的香菇多糖提取方法。     

微波法从蛹虫草中提取虫草多糖的技术研究

以蛹虫草(Cordycepsmilitaris)为原料,采用微波法对其虫草多糖的提取工艺进行了探讨。通过对其微波功率、提取时间和料水质量比进行正交优化,得到一个最佳提取工艺条件为:微波功率700 W、提取时间2.0 min、料水质量比1:60。通过正交优化的多糖得率为3.78%,比常规热水浸提法高出0.79个百分点。故此,利用微波法从蛹虫草中提取虫草多糖具有得率高、能耗小、操作简单等优点。     

马齿苋多糖微波提取条件的优化

本文对微波辅助法提取马齿苋多糖的工艺进行了研究,分析了提取温度、提取时间、料液比对马齿苋多糖得率的影响,确定了微波辅助提取马齿苋多糖的最佳工艺条件为60℃,料液比1 g/30 mL,提取10min。在此条件下的多糖得率为13.87%。     

Two Extraction Methods of Lentinan Polysaccharide

采用正交试验比较研究热水浸提法和微波提取法提取香菇多糖.热水浸提法的最佳工艺为:提取温度70℃、提取时间4h、料液比1∶15,提取率3.243 ％;微波提取法的最佳工艺为:微波功率560W、微波处理时间60 s、料液比1∶10,提取率4.771％.微波提取法效率高、时间短,是理想的香菇多糖提取方法.     

胶束介导联合超声—微波辅助法提取喜树叶中喜树碱及羟基喜树碱

为了寻找一种新的方法从喜树叶中提取喜树碱和羟基喜树碱,充分利用喜树资源,以喜树叶粉末作为提取原料,采用超声—微波辅助提取技术提取喜树叶中活性成分喜树碱和羟基喜树碱。采用响应面优化方法设计,分别考察微波时间、料液比、微波功率、表面活性剂的浓度4个因素对总提取率的影响,优化得到最佳提取工艺条件。研究结果表明：当微波时间为10.5 min、料液比为1∶60、微波功率为850 W、表面活性剂浓度为 8.5 g·L^-1时总提取率达到最佳。最佳工艺下总提取率为0.056 4%。     

提取防风多糖的工艺优化

采用超声波强化和微波辅助提取2种方法提取防风多糖,并与传统热水浸提法在多糖的提取率上进行比较。防风多糖超声提取的最佳工艺条件为超声功率1 000 W、提取时间25 min、液固体积质量比为25,防风多糖微波提取的最佳工艺条件为微波功率560 W、液固体积质量比为30、提取时间10 min,在最佳提取工艺下,2种方法的提取率分别为6.103%和7.639%。与传统热水浸提法相比,超声法和微波法提取防风多糖具有迅速、节能、高效、提取率高等诸多优点。     

响应面法优化微波法提取荷叶中总黄酮的研究

采用微波提取法对荷叶总黄酮进行提取,通过响应面试验分析确定最佳的荷叶总黄酮的最佳提取工艺:微波功率346.57W,微波时间1.04min,料液比1:28.21,乙醇浓度69.65%,理论提取率为5.02%。经3次平行试验的实际平均提取率为4.98%。     

中国苋属nrDNA的ITS序列分析及其系统学意义

运用ＰＣＲ直接测序法,对苋属（Ａｍａｒａｎｒｈｕｓ Ｌ．）１５个种及外类群鸡冠花（Ｃｅｌｏｓｉａ ｃｒｉｓｔａｔａ Ｌ．）ｎｒＤＮＡ的ＩＴＳ区（包括ＩＴＳ－１,５．８５ｒＤＮＡ和ＩＴＳ－２）进行序列测定。结果表明苋属植物的ＩＴＳ序列总长度为６２９－６３２ｂｐ,长度变异仅发生在ＩＴＳ－１区（２５０－２５３ｂｐ）。采用ＰＡＵＰ软件进行系统发育分析表明：分布于中国的苋属植物可分为３组,即刺苋组（ｓｅｃｇ     

Sequence Analysis of the ITS Region of Nuclear Ribosomal DNA (nrDNA) in Chinese Amaranthus and Its Systematic Utility

The sequences of the ITS region (including ITS-1, 5.8S rDNA and ITS-2) of nuclear ribosomal DNA from 15 species of the genus Amaranthus L. and outgroup Celosia cristata L. were determined. The result shows that the size of the ITS region of Amaranthus is from 629 to 632 bp, and the length variation is only found in ITS-1 (250-253 bp). On the basis of phylogenetic analysis of nucleotide sequences, the Amaranthus species in China may be devided into three sections, viz., sect. Spinosus, sect. Amaranthus and sect. Paucestamen; the cultivated species, viz., Amaranthus paniculatus L., A. cruentus L., A. caudatus L. and A. hypochondriacus L. can be treated as the subsp. of A. hybridus L.; A. taishanensis F.Z.Li and A. tenuifolius Willd are both closely related to species in the sect. Paucestamen. The study also indicated that the number of stamens has more phylogenetic information than other characters, such as the number of sepals and dehiscence/indehiscence of fruits in Amaranthus.     

Studies on callus growth and morphogenesis in several species and lines of t Amaranthus

A study has been carried out on several Amaranthus L species and breeding lines (A. caudatus, A. cruentus, A. hybridus, A. hypochondriacus), some of which have previously shown poor or no plant regeneration from callusing primary explants. Callus formation occurred from explants from almost all the lines tested. Significant differences in callus growth were observed among the lines depending on the growth regulator combinations used. Cultural conditions such as type and growth regulator combination, as well as age-dependent competence of the explant tissues, also influenced the frequency of shoot (and/or root) regeneration in Amaranthus species that had been shown difficult to regenerate in the past. The results obtained demonstrate that in Amaranthus the genotype, growth regulator dose and combination, the type and the physiological stage of explant are factors of great importance for in vitro plant regeneration. This revised version was published online in June 2006 with corrections to the Cover Date.     

向日葵茎芯多糖的提取工艺优化及其体外抗肿瘤活性研究

研究了向日葵茎芯中主要活性物质多糖的提取工艺,并对此工艺进行了优化,选取的提取方法为水提醇沉法,以多糖含量作为指标,采用单因素试验研究了提取次数、原料颗粒的大小（目数）、料液比、提取时间、提取温度对向日葵茎芯多糖含量的影响。用苯酚-硫酸法测定提取液中多糖的含量,得出向日葵茎芯中多糖的最佳提取工艺条件为：提取次数2次,原料颗粒的大小（目数）60~80目,料液比（g·mL^-1）1：50,提取时间3.0 h,提取温度90℃,在最优提取条件下,多糖的提取得率为6.56%,多糖的含量为266.03 mg·g^-1。本文也对多糖的体外抗肿瘤活性进行了研究,结果表明向日葵茎芯多糖的体外抗肿瘤活性较弱。这些条件的确定为向日葵茎芯的深入研究奠定了基础。     

Fertility, segregation at a herbicide-resistance locus, and genome structure in BC hybrids from two important weedy Amaranthus species

Field studies have established high potential for hybridization between two important and often coexisting weedy species, Amaranthus hybridus and Amaranthus tuberculatus. Prezygotic reproductive barriers between these species are believed to be limited to pollen competition and availability. A greenhouse study showed that a herbicide-resistance gene (ALS) from A. hybridus could be introgressed into an advanced A. tuberculatus background (BC2). However, evidence is lacking in support of such transfer in nature. Postzygotic reproductive barriers may minimize, if not preclude, natural introgression. Indeed, A. hybridus xA. tuberculatus hybrids are characterized by reduced fertility and even floral neuterism. The purpose of this study was to assess hybrid fertility in the BC1 generation and its relationship with genome structure and segregation at ALS. Fertility was assessed by measuring seed output and by pollen evaluation, and segregation at ALS was determined via a molecular marker system. The two parental species have the same ploidy (2n = 32) but differ in DNA content (2C) values, with A. tuberculatus chromosomes being on average 29% greater than those of A. hybridus. Given that most (98%) BC(1)s were homoploid, 2C values were used as indicators of relative genomic constitution. Fertility in the BC1 generation was greater than that of F1s, and 3% of BC1s had seed output similar to that of the parental species. Fertility in the BC1 did not correlate (in a strict way) with reconstitution of parental genomes. Hybrid sterility appeared to be controlled by relatively few loci. Heterozygosity at ALS was negatively correlated with fertility. Also, the A. tuberculatus ALS allele was not observed in the A. hybridus sexual condition, monoecism. Linkage of ALS to a locus associated (directly or via epistasis) with hybrid sterility may explain the fertility penalty observed with ALS introgression. Moreover, this linkage might explain why sequenced herbicide-resistance ALS alleles from sympatric A. tuberculatus and A. hybridus populations show independent evolution.     

Amplified fragment length polymorphism-based genetic relationships among weedy Amaranthus species

Weedy Amaranthus species frequently cause economically significant reductions in crop yields. Accurate identification of Amaranthus species is important for efficient weed control, but Amaranthus species can interbreed, which might cause difficulty when identifying hybrid-derived specimens. To determine which of several economically important weedy Amaranthus species are most genetically similar, and thus most likely to produce viable hybrids, we performed amplified fragment length polymorphism (AFLP)-based unweighted pair group method with arithmetic mean (UPGMA) analysis on 8 of these species, with 141 specimens representing 98 accessions. The analysis grouped the specimens into four principal clusters composed of Palmer amaranth (Amaranthus palmeri S. Wats.) and spiny amaranth (Amaranthus spinosus L.); Powell amaranth (Amaranthus powellii S. Wats.), redroot pigweed (Amaranthus retroflexus L.), and smooth pigweed (Amaranthus hybridus L.); waterhemp (Amaranthus tuberculatus (Moq.) Sauer) and sandhills amaranth (Amaranthus arenicola I.M. Johnst.); and tumble pigweed (Amaranthus albus L.). The cluster analysis provided evidence suggesting hybridization among Powell amaranth, redroot pigweed, and smooth pigweed. Further investigations using molecular analysis of the ribosomal internal transcribed spacer region from atypical plants supported this notion. Three species, Palmer amaranth, sandhills amaranth, and waterhemp, are dioecious; nevertheless, the Palmer amaranth and waterhemp-sandhills amaranth clusters were distinct from each other. The Palmer amaranth-spiny amaranth cluster included a cluster of Palmer amaranth and two clusters of spiny amaranth, a monoecious species. Thus the dioecious species Palmer amaranth and waterhemp may not necessarily hybridize with each other more readily than they would to one or more of the monoecious Amaranthus species.     

The status of Amaranthus bouchonii Thellung within Amaranthus L. section Amaranthus: new evidence from studies of morphology and isozymes

WILKIN, P., 1992. The status of Amaranthus bouchonii Thellung within Amaranthus L. section Amaranthus: new evidence from studies of morphology and isozymes. The introduction of the closely related weedy taxa of Amaranthus L. section Amaranthus into Europe has resulted in a number of taxonomic problems, especially regarding the rank of A. bouchonii Thell. Electrophoretic separation of five isozymes (phosphoglucoisomerase, phosphoglucomutase, glutamate oxaloacetate transaminase, malate dehydrogenase and menadione reductase) and morphological studies were used to generate new data on this problem, and canonical discriminant analysis of morphometric characters was carried out. The results obtained support the maintenance of A. bouchonii as a distinct taxon, most closely related to A. powellii S. Wats. The origin of this taxon is considered, and the monomorphism of the isozymes studied is discussed in the light of the extensive morphological variation within species in section Amaranthus.     

Chloroplast-coded atrazine resistance in Solanum nigrum: psbA loci from susceptible and resistant biotypes are isogenic except for a single codon change

The 32-kDa photosystem II protein of the chloroplast is thought to be a target molecule for the herbicide atrazine. The psbA gene coding for this protein was cloned from Solanum nigrum atrazine-susceptible ('S') and atrazine-resistant ('R') biotypes. The 'S' and 'R' genes are identical in nucleotide sequence except for an A to G transition, predicting a Ser to Gly change at codon 264. The same predicted amino acid change in psbA was previously shown for an Amaranthus hybridus 'S' and 'R' biotypes which had, in addition, two silent nucleotide changes between the genes (Hirschberg, J. and McIntosh, L., Science 222, 1346-1349, 1983). Occurrence of the identical, non-silent change in psbA in different 'S' and 'R' weed biotype pairs suggests a functional, herbicide-related role for this codon position.     

藿香枝叶多糖的提取工艺及其清除羟基自由基作用研究

采用苯酚-硫酸,并以超声法辅助提取野生藿香枝叶中的多糖,设计L9(34)正交试验考察料液比、pH和超声提取时间对藿香枝叶中多糖提取的影响,并对藿香多糖进行清除.OH试验。结果表明,藿香多糖的最佳提取工艺为料液比1∶10,超声提取30min,pH值为6,可使藿香多糖的提取率高达7.50%。藿香多糖对羟基自由基有显著地清除效果,表明其有抗氧化作用。     

响应面法优化土茯苓多糖除蛋白工艺

为了优化土茯苓(Smilax glabra Roxb.)多糖溶液除蛋白的工艺,采用Sevage试剂法除蛋白,在单因素实验的基础上,以多糖保留率和蛋白清除率为指标,使用响应面法对Sevage试剂法除蛋白工艺进行优化。结果显示,Sevage试剂法去除土茯苓多糖的最佳工艺为采用Sevage试剂:供试液=1:3、振摇强度8挡、振摇时间10 min、除蛋白次数5次,蛋白清除率为97.39%,多糖保留率为74.13%。优化后的除蛋白工艺重复性好,与理论值误差较小,可用于土茯苓多糖除蛋白。