响应面法优化脚板薯皂苷提取工艺

[目的]优化脚板薯皂苷的最佳提取工艺.[方法]探讨提取温度、提取时间、料液比和乙醇浓度对脚板薯皂苷提取率的单因素影响.在此基础上,采用响应面分析方法,进一步研究各自变量及其交互作用对脚板薯皂苷提取率的影响,并对其工艺参数进行优化.[结果]脚板薯皂苷提取的最佳工艺条件为提取温度76℃、提取时间1.5h、乙醇浓度90％、料液比1：30（m/v）,在此最优工艺条件下,脚板薯皂苷提取率达0.291％.[结论]该研究可为脚板薯皂苷的工业化生产提供理论指导.     

化学试剂对翅荚决明种子萌发和幼苗早期生长的影响

为探讨不同化学试剂对翅荚决明(SennaalataL.)种子发芽率和幼苗生长的影响,用4种不同浓度的化学试剂(KNO3、GA3、KMnO4和NaOH)分别处理种子。结果表明:0.5~4.0g/LKMnO4和0.05~0.4g/LGA3浸种显著促进种子萌发,加快幼苗生长速度,其中以0.1g/LGA3和4g/LKMnO4浸种24h效果最佳,是解除翅荚决明种子休眠、促进幼苗生长的有效措施;1~8g/LKNO3浸种显著促进了种子萌发,但对幼苗生长影响不明显;而5~40g/LNaOH浸种明显抑制种子萌发和幼苗生长,且随着浓度增加,抑制作用明显增大。。     

山药PAL基因全长cDNA序列的克隆、表达与分析

为了阐明苯丙氨酸解氨酶(PAL,EC4.3.1.5)基因在山药地下块茎酚类物质积累过程中的分子机理,本研究运用普通PCR、RACE和TAIL-PCR技术从大薯(Dioscorea alataL.)’Zixiao’地下块茎中克隆到同一个PAL基因的3个片段,即长度分别为1 145bp、1 151bp和424bp的中间片段、3’端和5’端的cDNA序列;将3段cDNA序列拼接后获得大小为2 376bp的PAL基因全长cDNA序列,该序列含有一个1986bp的最大开放阅读框(ORF),一个28bp的5’端非翻译区,一个362bp含25 nt的Poly(A+)尾的3’端非翻译区,最大ORF可推测编码一个包括PAL酶活性中心的特征序列(GTITASGDLVPLSYIA)在内的661个氨基酸的多肽,分子量为71.974kDa,等电点6.310;大薯地下块茎的PAL基因分别在核苷酸与氨基酸水平上和GenBank中所选已知其他物种的同源性为73%~77%和76%~82%,说明PAL基因在系统进化上相对保守;RT-PCR分析表明该基因仅在地下块茎中表达,而且表达丰度在收获前逐渐降低。     

翅柃扦插繁殖技术研究

以翅柃为试验材料,对其进行了不同时间、不同激素及不同激素浓度处理的扦插试验。试验结果表明,翅柃扦插繁殖应选择在秋季进行,采用50 mg.L-1浓度的吲哚丁酸通过17 h的浸泡,其成活率可达到62%。     

参薯多糖检测及其体外抗氧化能力研究

以参薯(Dioscorea alata L.)块茎为研究材料,采用热水浸提、Savage法除蛋白、乙醇沉淀及有机溶剂纯化的方法,获得参薯粗多糖.通过蒽酮-硫酸显色法测定参薯的多糖含量,研究了参薯粗多糖体外对羟自由基(·OH)和过氧化氢(H2O2)的清除能力.结果表明:参薯多糖含量高达19.17％,参薯粗多糖对羟自由基(...     

Dioscorea alata (Water Yam) as a Replacement for Maize in Diets for Laying Hens

One hundred and twenty-six point-of-lay birds were randomly alloted into six groups of 21 birds each and fed six diets containing 0%, 10%, 20%, 30%, 40% or 50% of Dioscorea alata meal as a replacement for maize, corresponding to 0%, 20%, 40%, 60%, 80% and 100% maize replacement. There were no significant differences (p>0.05) in feed intake, egg weight or feed efficiency between the control diet and the test diets. However, the daily egg production per 100 birds (hen day production), differed significantly (p>0.05) among the treatments. The birds on the control diet and diets with substitution rates of up to 80% laid significantly (p>0.05) more eggs than those on the 100% substitution rate.This shows that D. alata can replace up to 80% of maize or constitute 40% of a laying chicken diet, provided the rations are isocaloric and isonitrogenous. For this to be achieved, more soybean and/or more fish scraps, and more palm oil are needed in the diets containing D. alata than in diets based on maize.     

Responses of white yam (Dioscorea rotundata) cultivars to inoculation with three viruses

The responses of 24 white yam ( Dioscorea rotundata ) cultivars to mechanical and vector transmission with each of three viruses infecting yams were assessed through enzyme-linked immunosorbent assay (ELISA) and symptom development. The viruses were Dioscorea alata virus (DAV), genus Potyvirus ; Dioscorea alata bacilliform virus (DaBV), genus Badnavirus ; and Cucumber mosaic virus (CMV), genus Cucumovirus . Only TDr 95-128, a landrace cultivar from Nigeria, developed symptoms of infection with CMV and DaBV following mechanical and vector transmission, respectively. PAS-ELISA showed that nine genotypes remained uninfected by DAV and 11 were uninfected by CMV or DaBV. Genotypes TDr 747 and TDr 1640 both showed resistance to all three viruses.     

花烟草自交不亲和性连锁的基因定位研究

自交不亲和性是植物界存在的一种普遍现象,据Ｅａｓｔ估计有３０００种以上的植物存在着自交不亲和性,自交不亲和是由于花粉雌蕊之间表现的抑制作用所致,研究表明烟草属于同形不亲和性中的配子体自交不亲和〔１〕。对烟草的自交不亲和研究表明,花粉可以在柱头上发生水...     

花烟草中黄酮类化合物种类及含量的分析

将加拿大引进的花烟草按花色分为九个大类,用潘通色卡进行花色标定,并采用分光光度计、光谱扫描和高效液相色谱仪对黄酮(醇)类物质的组成及含量进行分析以此推测花色素成分。结果表明,各色花烟草中均不含有类胡萝卜素、C3-OH氢游离的黄酮醇、查儿酮,都含有橙酮,且除白色花外,均含有花青苷,紫色系的花青苷含量最高,可知花青苷是影响花色的主要因素。     

压热法制备紫山药抗性淀粉

[目的]研究压热法制备紫山药抗性淀粉的工艺.[方法]以紫山药淀粉为原料,采用压热法制备紫山药抗性淀粉.以抗性淀粉得率作为评价指标,在单因素试验基础上,通过正交试验和方差分析明确因素影响的重要性并优化工艺条件.[结果]试验表明,影响抗性淀粉得率的因素主次顺序为:淀粉乳浓度＞温度＞pH＞时间,最佳工艺条件为:淀粉乳浓度为30％,温度为120℃,pH为7,时间为60 min,在此条件下抗性淀粉得率为12.92％.[结论]研究可为开发紫山药抗性淀粉产品提供理论依据.