山薯试管零余子的诱导

以山薯无菌苗茎段为试验材料,研究BA、NAA、JA、蔗糖浓度、光周期以及不同培养方式对试管零余子诱导形成的影响.结果表明,MS+2.0mg/L BA+0.1 mg,L NAA+80g/L蔗糖+5.0g/L,琼脂+1.5 g/L活性炭,12 h/d的光照时间(光照强度为2 000 lx)是试管零余子诱导较优的培养条件.经过2个月的培养,试管零余子诱导率达90%以上,零余子发生个数为1.44个/株.蔗糖浓度是影响试管零余子发生的最重要因素,高蔗糖浓度(80 g/L)能促进试管零余子的发生.     

蔗糖、多效唑、ABA、KT对淮山薯试管珠芽诱导的影响

以淮山薯不定芽为材料,采用正交试验设计方法研究了蔗糖、多效唑(PP333)、脱落酸(ABA)、激动素(KT)对淮山薯试管珠芽诱导的影响。结果表明:①组合MS+蔗糖90 g/L+PP333 2.0 mg/L+ABA 12 mg/L+KT 1.0 mg/L最有利于淮山薯试管珠芽的诱导,珠芽诱导率84.46%,平均珠芽数4.45个;②蔗糖是影响珠芽诱导率和平均珠芽数的主导因子,脱落酸是影响珠芽大小的主导因子;③较高浓度的蔗糖(90 g/L)有利于淮山薯试管珠芽的诱导,平均诱导率77.63%,平均珠芽数4.12个。     

淮山组织培养的多因子正交试验研究

[目的]以淮山茎段作为外植体,进行淮山的离体快速繁殖研究。[方法]按L9(34)正交试验表,选用MS培养基,附加不同浓度的GA3、6-BA、NAA和活性碳,分析比较不同培养成分对淮山茎段分化和增殖的影响;选用不同浓度的MS无机盐浓度、NAA、活性碳和蔗糖,比较了不同培养基对淮山组培苗生根的影响。[结果]培养基MS+GA30.25 mg/L+6-BA1.0 mg/L+NAA 0.2 mg/L+活性炭0.5 g/L,对淮山茎段分化和增殖的效果最好;最佳节生根培养基配方为1/2MS+NAA0.5 mg/L+活性炭0.5 g/L+蔗糖30 g/L。[结论]建立起桂淮5号的组培快繁技术。     

阿希蕉合生花组培快繁技术研究

阿希蕉为野生香蕉资源,可作为重要的遗传育种资源并具有观赏价值。本研究以阿希蕉合生花为植物材料,进行组培快繁技术研究。结果表明,阿希蕉在巴西蕉愈伤诱导培养基上可诱导出愈伤组织,最佳芽分化培养基配方为MS+6-BA（3.0 mg/L）+NAA（0.1~0.2 mg/L）,最佳芽增殖培养基配方为MS+6-BA（2.0 mg/L）+NAA（0.1 mg/L）,最佳生根培养基配方为MS+IBA（3.0 mg/L）+NAA（0.3 mg/L）。从取材到获得根系完整的组培苗约需100 d,繁殖效率100株/花苞以上,增殖效率高,可达到快速繁育的目的。     

姜荷花‘红色印象’工厂化组培育苗技术研究

以姜荷花‘红色印象’植株的多个部位作为外植体,进行丛生芽诱导、增殖扩繁、生根壮苗以及出瓶移栽育苗的研究,完善姜荷花工厂化组培快繁流程,为其规模化生产提供参考。以姜荷花球茎、储藏根、球茎小芽、侧芽、幼嫩花芽、幼嫩叶片6个部位为材料,通过添加不同浓度6-BA和NAA的MS培养基,对丛生芽诱导培养、丛生芽增殖培养、生根壮苗以及移栽育苗等步骤进行优化。姜荷花‘红色印象’最佳外植体为球茎小芽和侧芽,诱导培养基为MS+6-BA (3 mg/L或5 mg/L)+NAA 0.2 mg/L+蔗糖30 g/L+卡拉胶7 g/L,最佳丛生芽增殖培养基为MS+6-BA3 mg/L+NAA0.1mg/L+蔗糖30g/L+卡拉胶7g/L,生根壮苗培养基选用1/2MS+NAA0.1mg/L+蔗糖20g/L+卡拉胶7 g/L,经过炼苗后出瓶移栽,组培苗种植基质选用细泥炭和细椰糠1∶1混合基质最佳,出瓶移栽成活率达95%以上,表型稳定。利用EST-SSR标记对母株和随机选择的组培苗进行扩增分析,证实DNA水平上无明显变异。通过对姜荷花‘红色印象’外植体和培养基的筛选,实现姜荷花组培快繁流程优化,建立高效完整的姜荷花工厂...     

2个葡萄品系外植体愈伤组织诱导和植株再生

进行了无核白、红地球2个葡萄品系外植体愈伤组织诱导和植株再生的研究。通过葡萄品系无核白、红地球叶片和叶柄外植体的愈伤组织的诱导、再分化,以器官发生途径实现植株再生。结果表明:(1)愈伤组织诱导以MS+BA5mg/L+NAA0.5mg/L+蔗糖40g/L培养基最佳,诱导率为35%;同一葡萄品种的叶片与叶柄诱导愈伤组织的频率基本相同,而红地球外植体诱导愈伤组织的频率高于无核白;(2)不定芽的诱导再生以1/2MS+BA0.5mg/L+NAA0.05mg/L+CH500mg/L+蔗糖30g/L培养基最佳,平均诱导率达35.4%;叶柄来源的愈伤组织诱导不定芽的频率高于叶片愈伤组织;(3)根系的诱导以1/2MS+KT0.5mg/L+IBA1.0mg/L+AC2g/L+蔗糖15g/L培养基最佳,无核白和红地球来源的不定芽诱导生根频率基本相同,都在80%以上。     

玉米幼胚培养及植株再生的研究

以不同玉米自交系幼胚为外植体,研究不同2,4-D浓度对愈伤组织诱导、6-BA浓度对愈伤组织分化和6-BA与NAA配合使用对试管苗生根的影响。结果表明:不同2,4-D浓度对愈伤组织诱导率影响差异不明显,但对胚性率诱导有明显影响,其诱导最佳培养基为MS+2,4-D 2 mg/L+水解酪蛋白500 mg/L+脯氨酸500 mg/L;愈伤组织分化的最佳培养基是MS+6-BA0.5 mg/L+水解酪蛋白500 mg/L+谷氨酰胺200 mg/L+PP₃₃₃ 2 mg/L;试管苗生根的最佳培养基是1/2 MS+6-BA0.5 mg/L+NAA2.0 mg/L+PP₃₃₃ 2.0 mg/L+活性炭0.2%。     

大苞鞘石斛组织培养快繁研究

为筛选出大苞鞘石斛组培快繁体系各阶段最适培养基配方,以大苞鞘石斛无菌苗茎段为外植体,通过正交试验研究不同因素对大苞鞘石斛植株再生的影响。结果表明:拟原球茎诱导最适培养基为1/2MS+2,4-D0.2 mg/L+蔗糖30 g/L,诱导出的拟原球茎直径1.5 mm时将其从茎段上剥离,并接入原培养基继续诱导15~20 d;拟原球茎增殖最适培养基为1/2MS+NAA 1 mg/L+蔗糖30 g/L+椰乳10%,继代周期25~30 d;拟原球茎分化最适培养基为1/2MS+NAA 0.5 mg/L+蔗糖30 g/L+椰乳10%,分化培养需40 d;将分化的无菌苗继代于花宝2号3 g/L+蛋白胨2 g/L+IBA 1 mg/L+蔗糖30 g/L+椰乳10%生根诱导效果最好,培养45 d;生根壮苗最佳培养基为花宝1号3 g/L+蛋白胨2 g/L+蔗糖30 g/L+活性炭1 g/L,培养50 d。     

弄岗马兜铃组培苗的生根培养

对弄岗马兜铃组培苗进行生根诱导研究,以达到可移栽的目的。在1/2改良MS固体培养基(KH2PO4 170 mg/L、蔗糖30 g/L,pH 5.8)中添加不同浓度的6-苄胺基腺嘌呤(6-BA)和吲哚丁酸(IBA)筛选最佳生根培养基配方。结果表明：在1/2改良MS固体培养基(蔗糖30 g/L,pH 5.8)加入1 mg/L的IBA具有较好的生根诱导作用,而6-BA对弄岗马兜铃组培苗不具有生根作用。     

“蜜宝”火龙果的组织培养技术

对“蜜宝”火龙果组织培养的外植体选择,不同培养基对腋芽诱导、丛生芽增殖及生根培养的影响等进行了研究。结果表明：近老熟茎段为最佳外植体,最适腋芽诱导培养基为MS+6-BA3.0 mg/L+NAA0.1 mg/L+琼脂6.4 g+蔗糖30 g,最适增殖培养基为MS+6-BA1.5 mg/L+NAA0.1 mg/L,最适生根培养基为1/2 MS+IBA0.5 mg/L+活性炭1 g/L+琼脂6.4 g+蔗糖30 g。     

Analysis of nutritional components of eight famine foods of the Republic of Niger

In the western Sahel, indigenous plants become important staples when cereal harvests are inadequate to support populations inhabiting that region of Africa. The purpose of this study was to assess the nutrient content of several of these edible wild plants. The leaves of the following seven plant foods were analyzed: Ziziphus mauritiana, Cerathotheca sesamoides, Moringa oleifera, Leptadenia hastata, Hibiscus sabdarifa, Amaranthus viridi, and Adansonia digitata. The fatty acid, vitamin E, carotenoid, selected mineral and amino acid contents of these plant foods were determined. These same analyses were performed on the fruit of the Adansonia digitata. In quantitative and qualitative terms, Amaranthus viridis was found to be an excellent source of protein. Its amino acid composition compared favorably to that of a World Health Organization (WHO) protein standard. It also contained considerable amounts of the two fatty acids that are essential in humans (linoleic and -linolenic) and a number of minerals including iron, magnesium, calcium and zinc. The leaves of Hibiscus sabdarifa contained an appreciable quantity of protein the composition of which was comparable to the WHO standard. The mineral content of the leaves of this plant was also exceptionally high; noteworthy was its high zinc content. H. sabdarifa also contained significant quantities of the two essential fatty acids. Ziziphus mauritiana was an excellent source of the essential fatty acid linoleic acid and several of the metals including iron, calcium, magnesium and zinc. Its content of other essential nutrients, however, was rather low. In general, Adansonia digitata leaves were nutritionally superior to the fruit of the tree; however, the fruit did contain useful quantities of potassium, phosphorus, zinc and -linolenic acid. The Leptadenia hastata leaves were an especially good source of lutein and -carotene. These data should be useful to the people who inhabit the western Sahel in helping them devise healthy diets during times when cereal staples are in short supply.     

狗牙根诱变后代抗寒性评价

通过电解质外渗法和匍匐茎恢复试验对‘阳江’狗牙根及其12个通过形态鉴定选出的坪用价值高且花序密度低的诱变后代进行抗寒性鉴定。电解质外渗法结果表明:诱变后代间的抗寒性具有较大差异,其叶片半致死温度(LT₅₀)的变异范围为-7.6～-0.2℃(最低值与最大值相差7.4℃);参试材料抗寒性由强到弱依次为M18>M4>M26>M28> M22>阳江>M29>M31>M10>M37>M16>M1>M25,其中,有5个诱变后代抗寒性优于亲本,分别是M18、M4、M26、M28、M22。匍匐茎恢复实验结果表明:诱变后代M1、M22、M26、M31、M25在0℃和-5℃低温胁迫后的恢复生长率都高于亲本,恢复能力均优于亲本;M10、M37、M28在-5℃低温胁迫下,恢复生长能力低于亲本,抗寒性相对较弱,M16和M4在0℃和-5℃低温胁迫下,恢复生长率都低于亲本,抗寒性明显弱于亲本。综合2种方法鉴定结果显示:诱变后代M1、M25的恢复能力较强;M4、M28的叶片抗寒性较好,青绿期较长;M22、M18、M26的叶片抗寒性和匍匐茎恢复能力均较强;M29,M31的叶片抗寒性和匍匐茎恢复能力与亲本相似;M10、M16、M37的叶片抗寒性和匍匐茎恢复能力均较弱,整体抗寒性较弱。     

芦笋枯萎病病原鉴定

对造成福建省漳州市东山县的芦笋枯萎病病原菌进行分子鉴定,以期确定病原菌的属、种名,为防治该病害寻求理论依据。试验对分离纯化的病原菌核糖体DNA的ITS区进行测序,在Genbank中搜索其同源性并构建它们的系统发育树,结果表明：引起芦笋枯萎病的病原菌是镰刀属中的尖孢镰刀菌(Fusarium oxysporum),且病原菌之间的同源性高达89%,遗传差异不显著。     

Size and frequency of occurrence of pre-roost gatherings of starlings

One hundred and fifty-six pre-roost gatherings of starlings were observed at 28 sites around a roost in west Norfolk during winter. Pre-roost gatherings occurred more frequently at individual farmyards compared with individual fields, but 82% of the sites where gatherings occurred were on fields. The size of gatherings was greater, the closer to the roost. Birds in pre-roost gatherings on fields of autumn-sown winter wheat spent most of the time feeding and had a diet composed almost exclusively of wheat seeds. Birds in gatherings on grass fields also fed intensively whereas only 31% of birds at farmyards were feeding. The implications that these results have with regard to potential damage to fields of winter wheat and around farmyards are discussed.     

橡胶树丛枝病病原的抗血清制备与应用

以感染橡胶树丛枝病病原的长春花为材料,制备得到橡胶丛枝病病原菌抽提液,以抽提液为抗原免疫家兔,制备抗血清,经微量沉淀测定,抗血清效价为１：２０４８。应用橡胶丛枝病抗血清检测橡胶褐皮病,无症苗木检出率达３０％－３７％,可疑的褐皮病树检出率达８５．７％。     

农杆菌注射法瞬时转化荔枝果实组织的研究

为了寻找一种高效的荔枝果实瞬时基因表达方法,本研究以荔枝品种‘新球蜜荔’（Litchi chinensis Sonn. var. ‘Xinqiumili’）为试材,利用农杆菌注射法对荔枝果实组织进行转化,研究了果实发育时期、菌株种类、注射部位、取样时间、菌液浓度等对转化效率的影响。结果表明：选择果肉已完全包裹种子的Ⅱb期果实进行连体注射,在果柄、果皮、种子、果肉分别注入OD₆₀₀值为2.4的农杆菌菌株GV3101,4 d后取样进行检测,4个组织的GUS染色率较高。本研究成功建立了适用于荔枝果实的基因瞬时表达系统,为今后快速鉴定荔枝果实相关基因功能提供了基础。     

《生物安全法》实施背景下基因编辑技术的安全评价与监管

2020年10月17日,《中华人民共和国生物安全法》(以下简称《生物安全法》)通过全国人大常委会的审议,自2021年4月15日起施行.生物技术的研究与应用安全是《生物安全法》涉及的主要内容之一,基因编辑作为近几年生物技术领域的研究热点,其安全性评价和监管备受关注.本文概述了基因编辑技术的应用现状,比较了不同国家对基因编...     

蝉拟青霉疏水蛋白PChyd基因表达模式分析及敲除载体构建

为深入研究昆虫病原真菌蝉拟青霉疏水蛋白PChyd基因的功能,根据蝉拟青霉基因组信息克隆疏水蛋白PChyd基因,对该基因序列进行生物信息学分析,使用qRT-PCR技术对其在不同培养条件或阶段下的表达模式进行分析,并通过酶切酶连的方法构建了该基因的敲除载体。结果表明：PChyd基因的开放阅读框序列全长303 bp,编码100 aa,包含22 aa的信号肽序列和70 aa疏水蛋白功能区域。系统发育分析显示该基因与粗糙虫草菌亲缘关系最近。qRT-PCR结果显示PChyd基因在PDA培养的菌丝体、诱导的附着胞、诱导的芽生孢子中表达量显著高于另外2个样品,其中芽生孢子表达量最高,暗示该基因在蝉拟青霉侵染初期和在昆虫血腔中定殖阶段可能具有重要作用。凝胶电泳结果表明,成功构建了该基因的敲除载体,扩增出含有上臂、HPH、下臂的3356 bp左右的片段。本研究为进一步探究蝉拟青霉疏水蛋白PChyd基因的致病机理、生防工程菌的改造奠定了基础。     

波罗蜜叶片突变体叶绿素含量测定和超微结构观察

波罗蜜（Artocarpus heterophyllus）是一种热带果树,至今对其突变体的研究少有报道。本研究以波罗蜜叶片为试验材料,探究其叶片出现白化和返绿现象的可能原因。（1）用分光光度计法、比色法测定波罗蜜叶片突变体和正常绿叶的叶绿素及叶绿素前体物质含量;（2）用叶绿素酶Elisa试剂盒测定叶绿素酶活性;（3）用透射电子显微镜对叶绿体的超微形态结构进行观察。研究结果表明：（1）不同叶色所产生的叶绿素a含量、叶绿素b含量、叶绿素总含量、类胡萝卜素含量均存在显著差异;（2）波罗蜜叶片突变体和正常绿叶的叶绿素合成前体物质含量之间并没有出现显著性差异;（3）对波罗蜜叶片的叶绿素酶活性进行测定时,发现其活性出现显著差异,但对其叶绿素含量的差异性并没有产生较大影响;（4）观察波罗蜜叶片内叶绿体超微形态结构时,发现正常绿叶的叶绿体形态完好且数量较多,白化叶和返绿叶的叶绿体内部结构存在缺陷,其原因是叶绿体基粒构建阶段受阻;基于测定波罗蜜叶片中的叶绿素、叶绿素前体物质含量和叶绿素酶活性,并观察波罗蜜叶片内叶绿体的超微形态结构,对得到的数据结果进行比较分析。本研究推测是在叶绿素合成阶段,原脱植基叶绿素合成叶绿素时受阻及叶绿体发不良导致波罗蜜出现白化和返绿现象,为今后进一步综合研究波罗蜜突变体提供理论依据。     

Mechanism of action of insecticidal secondary metabolites of plant origin

Insect pest management is facing the economic and ecological challenge worldwide due to the human and environmental hazards caused by majority of the synthetic pesticide chemicals. Identification of novel effective insecticidal compounds is essential to combat increasing resistance rates. Botanicals containing active insecticidal phytochemicals appear to be promising to address some of these problems. Therefore, there is a continuous need to explore new active molecules with different mechanisms of action. Secondary metabolites present in plants apparently function as defense (toxic), which inhibits reproduction and other processes. The phytochemical biomolecules could be used for maximizing the effectiveness and specificity in future insecticide design with specific or multiple target sites, while ensuring the economic and ecological sustainability. In this article, the current state of knowledge on phytochemical sources and insecticidal activity, their mechanism of action in insects, resistance, and promising advances made in phytochemical research are reviewed.