NaCl胁迫对两种铁线子属果树叶片生理特性的影响

采用盆栽试验法,对铁线子属果树人心果[Manilkara zapota(L.)van Royen]和古巴牛乳树[Manilkara roxburghiana(Wight)Dubard]进行NaCl胁迫处理,测定叶片的叶绿素、超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、游离脯氨酸、可溶性蛋白等指标及盆土的实际盐度。结果表明,人心果在盐度1.98‰以内、古巴牛乳树在盐度2.42‰以内没有盐害;在NaCl胁迫下,两树种的叶绿素合成受到明显抑制;随着处理浓度增加,人心果叶片的SOD活性升高,各处理浓度下的活性都显著高于对照,但POD和CAT活性呈现先升后降趋势,古巴牛乳树叶片的CAT活性升高,但SOD和POD活性降低,三者活性在各处理浓度下都显著高于对照;人心果叶片的脯氨酸含量在各处理浓度均显著高于对照,可溶性蛋白含量在处理浓度为4‰及以上时显著高于对照,古巴牛乳树叶片的脯氨酸、可溶性蛋白在处理浓度为4‰及以上时显著高于对照,推测脯氨酸、可溶性蛋白作为渗透调节物质在人心果、古巴牛乳树受NaCl胁迫过程中起着重要的作用。     

不同NaCl预处理对低温胁迫古巴牛乳树幼苗叶片色素含量的影响

对古巴牛乳树盆栽苗进行不同浓度的NaCl预处理及热激预处理，探索其对低温下古巴牛乳树[Manilkara roxburghiana (Wight) Dubard]叶片色素的影响。结果表明：6‰NaCl预处理能有效缓解古巴牛乳树幼苗叶片受低温伤害，总叶绿素、叶绿素a及叶绿素b均较高于其它处理，此时盆土的实际盐度是3.70‰。     

NaCl胁迫下神秘果叶片的生理响应

为明确神秘果(Synsepalum dulcifcum Denill)的耐盐能力,研究其在NaCl胁迫下的适应机制并丰富果树的耐盐机理,通过盆栽试验法,以0、2‰、4‰、6‰、8‰NaCl溶液分别对幼苗进行胁迫处理,测定叶片叶绿素、渗透调节物质、抗氧化物酶、丙二醛含量及土壤实际盐度。结果表明:在NaCl胁迫下,神秘果叶片的叶绿素合成受到明显抑制;超氧化物歧化酶(SOD)和过氧化物酶(POD)的活性随浓度增加而显著升高,过氧化氢酶(CAT)活性则是先升后降,在4‰时达到最高;可溶性蛋白含量与处理浓度呈负相关;脯氨酸、可溶性糖含量和对照相比有显著增加,推测脯氨酸和可溶性糖在胁迫过程中起着重要的渗透调节作用。     

NaCl胁迫对古巴牛乳树矿质离子吸收的影响

了研究古巴牛乳树在NaCl胁迫下的离子效应及抗性方式,本试验测定了古巴牛乳树根、枝条、叶在NaCl胁迫下Cl－、Na＋、K＋、Ca2＋的含量及分布特点。结果表明：古巴牛乳树根、枝条、叶的Cl－、Na＋、Ca2＋含量随处理浓度的提高而增加,K＋、K＋/Na＋随处理浓度升高而降低;在8‰处理浓度时,根、枝条、叶中的Cl－含量分别为对照的7.86、11.82、16.53倍,Na＋含量分别为对照的3.36、3.04、4.40倍,K＋/Na＋分别为0.17、0.25、0.16;相同处理浓度下,Cl－、K＋、Ca2＋     

NaCl胁迫对野生及栽培大豆渗透调节物质含量的影响

采用沙培试验对NaCl胁迫条件下野生及栽培大豆叶片中可溶性糖、脯氨酸、可溶性蛋白质含量以及地上部及根部Na+、K+含量进行了测定.结果表明:0～200 mmol·L-1浓度范围内,随着NaCl胁迫浓度的增加,野生大豆叶片可溶性糖、脯氨酸含量均逐渐增加,可溶性蛋白含量先升高后降低;栽培大豆脯氨酸含量逐渐升高,可溶性糖及蛋...     

黄麻耐盐性评价及盐胁迫下的生理响应

试验采用水培法,对20份黄麻种质材料进行250 mmol/L NaCl胁迫处理,通过测定株高、茎粗、水上鲜重、水下鲜重、整株鲜重、水上干重、水下干重、整株干重,利用隶属函数法、聚类分析法确定各供试材料耐盐等级,将不同耐盐等级的材料进行0、150、250 mmol/L NaCl处理,测定其可溶性糖、可溶性蛋白以及游离脯氨酸含量。结果表明:不同黄麻种质资源间耐盐性存在显著差异,根据耐盐性综合评价值D值可将其分为3类,强耐盐材料有8份,中度耐盐材料8份,盐敏感材料4份;在NaCl胁迫下,不同耐盐等级的黄麻种质材料叶片内可溶性糖和游离脯氨酸含量都显著升高,而可溶性蛋白的含量显著下降,在150 mmol/L NaCl处理下,青皮大麻叶片内可溶性糖和游离脯氨酸的含量显著高于甜麻和南阳长果,可溶性蛋白的含量显著高于南阳长果,在250 mmol/L NaCl处理下,甜麻叶片内可溶性糖、游离脯氨酸和可溶性蛋白的含量显著高于南阳长果和青皮大麻。     

盐胁迫对蚕豆植株光合性能和渗透调节能力的影响

用0、50、150、250 mmol/L NaCl处理蚕豆幼苗一定时间后,分别测蚕豆植株的光合性能,根、茎、叶的含水量、渗透势以及有机渗透调节物质可溶性糖和脯氨酸的含量.结果表明:随盐处理浓度的增加,蚕豆叶片净光合速率、蒸腾速率、气孔导度均降低,胞间CO2浓度则呈上升变化趋势;蚕豆根、茎、叶的含水量和渗透势逐渐降低,渗透调节能力增强;可溶性糖的含量均高于对照,且在50 mmol/L NaCl条件处理下可溶性糖含量最高;脯氨酸的含量除在50 mmol/L NaCl条件下稍有下降外,随盐处理浓度的增加也大幅度增加.     

混合盐胁迫下马铃薯渗透调节物质含量的变化

以紫花白品种为试验材料,在离体条件下研究了NaCl和Na2SO4两种混合盐胁迫下马铃薯脱毒苗叶片中几种渗透性物质含量的变化。NaCl和Na2SO4分别按2:1,1:1和1:2摩尔比例混合,每一种比例下设7个盐浓度梯度,即0%、0.15%、0.30%、0.45%、0.60%、0.75%及0.90%。混合盐胁迫下,马铃薯叶片脯氨酸含量随着盐浓度的升高而升高,蛋白质含量和可溶性糖含量则随着盐浓度的升高而降低。盐浓度对马铃薯叶片可溶性糖含量、可溶性蛋白含量及脯氨酸含量影响极显著;盐组合对叶片可溶性蛋白含量影响极显著,但对可溶性糖含量和游离脯氨酸含量影响不显著;盐浓度和盐组合交互作用对马铃薯叶片可溶性糖含量、可溶性蛋白含量及脯氨酸含量影响不显著。     

NaCl处理对野大豆生理生化特性的影响

为明确NaCl处理条件下野大豆叶片抗氧化酶和有机渗透调节物质的变化,以不同浓度NaCl处理野大豆幼苗,对其抗氧化酶活性和渗透调节物质含量的变化进行分析.结果显示:随着NaCl浓度的升高,野大豆叶片中超氧化物歧化酶(SOD)、过氧化物酶(POD)活性先升高后降低,而过氧化氢酶(CAT)的活性呈持续下降趋势;丙二醛(MDA)含量在低盐度处理范围内变化不明显,高浓度NaCl处理时明显高于对照;随着NaCl浓度的升高,渗透调节物质脯氨酸含量增加,可溶性糖(SS)呈现先降低后升高的趋势.研究表明:在NaCl处理下野大豆主要通过SOD、POD清除活性氧,脯氨酸可能起到主要的渗透调节作用.     

秋石斛‘三亚阳光’中苗低温胁迫生理响应研究及耐寒指标筛选

对秋石斛‘三亚阳光’中苗进行15、10和5 ℃胁迫处理,测定各处理样品的电导率、可溶性蛋白、可溶性糖、游离脯氨酸、丙二醛、叶绿素含量、恢复生长之后的落叶率等耐寒生理指标,分析这些耐寒指标在胁迫下的变化规律,筛选出有效的耐寒评价生理指标。结果表明,电导率及可溶性蛋白、可溶性糖、游离脯氨酸、丙二醛含量和落叶率均随着处理温度的降低和处理时间的延长呈现上升趋势,而叶绿素含量则呈现逐渐下降的趋势。相关性分析发现,可溶性糖、游离脯氨酸、丙二醛、叶绿素含量和落叶率都与半致死温度有极显著的相关性,表明可溶性糖、游离脯氨酸、丙二醛、叶绿素含量和落叶率可作为秋石斛‘三亚阳光’耐寒性综合评价的有效评价指标。研究结果可以为秋石斛种质资源的耐寒性评价提供了理论依据和技术方法。     

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。     

中耕方式对土壤理化特性及玉米生长发育影响研究Ⅰ.中耕方式对玉米生长发育的影响

2002～2003年在0～3次中耕条件下研究了中耕方式对玉米生长发育和产量形成的影响。结果表明,多次中耕增大了玉米倒伏率,降低了玉米最大叶面积指数、株高及各时期叶片叶绿素含量,对花粒期玉米净光合速率、气孔导度、蒸腾速率也产生一定的负面影响。少中耕有增产的趋势,并且可以降低生产成本、增加经济效益。     

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％。     

12份白花泡桐材料亲缘关系的ISSR分析

以‘福桐’、‘绿桐’2个无性系与10个不同种源的白花泡桐个体为研究对象，采用ISSR分子标记对12份白花泡桐材料的亲缘关系进行研究，并利用DPSv3.01进行聚类分析。结果表明：10条引物共扩增出66条条带，其中有37条多态带，多态性比例为56.1%。根据ISSR聚类分析结果，在遗传距离为0.35时，12份白花泡桐材料可分为5类，第1类为‘福桐’无性系与河南、河北种源个体；第2类为‘绿桐’无性系与湖南、湖北、江苏种源个体；第3类为浙江、广东种源个体；第4类为江西、福建种源个体；第5类为广西种源个体。此结果     

论长白山人参主要品种类型栽种方式及其商品分类

本文论述了长白山人参主要品种类型的栽种方式、总结其规范化种植的工艺流程、对各人参品种类型栽种方式、技术要点、品种退化的主要原因及其解决措施作了详细的研讨。强调指出人参的各种栽种方式必须实施GAP标准化管理才是最好的栽种方式。重点报告了人参主产区,最新最好的栽种方式。并对人参商品分类及野山参分等质量标准中的野山参、移山参的定义提出修改意见,为提高我国人参产品质量在国际市场上的竞争能力,保持人参产业可持续发展提供科学依据。     

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.     

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。     

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.