野茼蒿链格孢YTH-21菌株的生物学特性及致病性研究

对野茼蒿(Alternaria sp.)YTH-21菌株的生物学特性及致病性进行研究,结果表明:该菌的菌丝体生长速度快,致病性强;菌丝体生长最适温度为25℃,产孢及孢子萌发最适宜温度均为30℃,致死温度为50℃、10min;菌丝体生长和产孢适宜pH值范围为5.0～8.0,最适宜于孢子萌发的pH值为7.0;对菌丝体生长及产孢最好的碳源为葡萄糖,但不利于孢子萌发;供试氮源以氯化铵对菌丝体生长及产孢表现出明显的抑制作用.     

芒果可可球二孢蒂腐病菌生物学培养特性

对芒果可可球二孢蒂腐病菌(Botryodiplodia theobromae Pat.)的生物学培养特性进行了研究.结果表明:菌丝生长最适温度30℃;孢子萌发最适温度30℃;菌丝生长最适pH值5～6,孢子萌发最适pH值7～10;菌丝生长的最佳碳源是棉子糖、葡萄糖,最佳氮源是牛肉浸膏、蛋白胨:光照及振荡培养对菌丝生长无显著影响;菌丝的致死温度为60℃,30 min或65℃,10 min,孢子的致死温度50℃,15min.     

海南芒果果腐病病原菌鉴定及其生物学特性研究

对引起芒果果腐病的病原菌进行鉴定,并对该病原菌的生物学特性进行初步研究。结果表明：引起芒果果腐病的病原菌是芒果拟盘多毛孢[Pestalotiopsis mangiferae（Henn.）Steyaert],该菌菌丝生长最适温度为25～28 ℃,孢子萌发最适温度为32 ℃,致死温度为60 ℃,10 min;菌丝生长最适pH为4～5,而孢子萌发最适pH为4;最适碳源为甘露醇,而麦芽糖不利于菌丝生长;最适氮源为牛肉浸膏、蛋白胨,而尿素不利于该菌菌丝生长;该菌适合在暗光交替和黑暗中生长。     

杧果畸形病病原菌的生物学特性的初步研究

杧果畸形病(Mango malformation disease)是世界各个杧果产区的重要病害。对发生在中国的杧果畸形病病原菌(Fusarium proliferatum)的生物学特性进行了初步研究。结果表明,病原菌生长的最适温度为24℃,最适pH为10;孢子萌发最适温度为24℃,最适pH值为5。病原菌能够利用试验的各种碳源和氮源,碳源以果糖最好,氮源以蛋白胨最好。连续光照处理菌丝生长速率高于交替光照或持续黑暗处理。分生孢子的致死温度为55℃,20min或者60℃,5min。     

杧果畸形病病原茵的生物学特性的初步研究

杧果畸形病（Mango malformation disease）是世界各个杧果产区的重要病害。对发生在中国的杧果畸形病病原菌（Fusarium proliferatum）的生物学特性进行了初步研究。结果表明,病原菌生长的最适温度为24 ℃,最适pH为10;孢子萌发最适温度为24 ℃,最适pH值为5。病原菌能够利用试验的各种碳源和氮源,碳源以果糖最好,氮源以蛋白胨最好。连续光照处理菌丝生长速率高于交替光照或持续黑暗处理。分生孢子的致死温度为55 ℃,20 min或者60 ℃,5 min。     

海南儋州甘蔗锈病病原菌的鉴定及其生物学特性的测定

根据症状和病原菌特征,确定海南儋州2007年新发现的甘蔗锈病是由黑顶柄锈菌（Puccinia melanocephala Sydow）引起的甘蔗褐锈病。该病菌夏孢子较适宜萌发的温度范围为18～25℃,最适萌发的温度为25℃。在相对湿度90％～100％及水滴中,夏孢子都可以萌发,其中以水滴中的萌发率最高。夏孢子萌发较适宜的pH值范围是5．5～7．5．最适宜pH为7．1。黑暗和2％0葡萄糖液可促进夏孢子的萌发。在-15℃、10℃,35～38℃干燥的环境条件下,夏孢子很容易失活。室内干藏两周半后,约一半的夏孢子失活。     

橡胶树褐根病病原菌生物学特性研究

对橡胶树褐根病病原菌Phellinus noxius Corner生物学特性进行研究.结果表明,菌丝生长的最适温度为28℃,最适pH值为6～7,该菌可有效地利用部分碳源和氮源,碳源以D-果糖和酵母浸出液最好,氮源以L-天门冬酰胺最好.光照处理对菌丝的生长有明显影响,黑暗利于菌丝生长,光照和黑光有抑制作用.菌丝的致死温度为55℃,10 min.     

龙眼拟茎点霉（Phomopsis longanae Chi）的生物学特性研究

龙眼拟茎点霉(Phomopsis longanae Chi)是导致采后龙眼果实腐烂的主要病原菌,研究了温度、湿度、pH值、光照、营养、越冬越夏等条件对龙眼拟茎点霉菌丝生长、产孢和孢子萌发的影响.结果表明:龙眼拟茎点霉生长适温为25℃,最适pH6～7;产生子座的最适温度为22～25℃,最适pH6,还需要一定的光照;以蔗糖、葡萄糖、可溶性淀粉和D-果糖为碳源和以蛋白胨、硫酸铵和硝酸铵为氮源的培养基最有利于龙眼拟茎点霉的生长发育;分生孢子的大量萌发要求高湿度和营养刺激,最适萌发温度25～28℃,最适pH6～7,在分生孢子器中,分生孢子的存活时间长于1年;该菌菌丝的致死温度为59℃(10 min),分生孢子为50℃(10 min).     

山竹蒂腐病病菌鉴定及其生物学特性研究

鉴定山竹蒂腐病的病菌,并对该病菌的生物学特性进行研究。根据病菌的培养性状、形态特征、寄主范围和致病性等特性,认为引起山竹蒂腐病的病原菌为可可球二孢菌(Botryodiplodia theobromae Pat.)。该菌菌丝生长的温度范围为10～40℃,最适为28～32℃;孢子萌发的温度范围为5～40℃,最适为28～32℃;在pH值3～11该菌均能生长,最适pH值为5～7;在全光照条件下,该菌菌丝生长最快;在供试碳源中,仅D-木糖不利于该菌菌丝生长,其它7种碳源对菌丝生长的影响无显著差异;在供试氮源中,牛肉     

剑麻茎腐病6个病原菌生物学特性的研究

对6株剑麻茎腐病原菌黑曲霉菌生物学特性的研究结果表明,在不同种类培养基、pH值、温度、光照等培养条件下病原菌生长速率有差异,病原菌的孢子生长的温度范围为10～44℃,最适温度为32℃,菌落生长的最适pH值为9,全光照条件下菌落生长最适,分生孢子的致死温度为60℃,50 min。     

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.