CaCl_2对棉花幼苗抗旱性的效应

用０．０１ｍｏｌ·Ｌ－１ＣａＣｌ２浸种和喷叶能减缓土壤干旱条件下棉花幼苗叶片相对含水量（ＲＷＣ）和水势（ψＷ）的降低，明显提高棉花的抗旱性。经ＣａＣｌ２浸种和喷叶的棉花幼苗叶片，在土壤干旱条件下，叶绿素含量、光合速率和呼吸速率下降幅度明显高于对照；超氧物歧化酶（ＳＯＤ）活性和过氧化氢酶（ＣＡＴ）活性下降幅度较小；丙二醛（ＭＤＡ）含量和细胞质膜相对透性增加幅度较小。说明ＣａＣｌ２浸种和喷叶都可以提高棉花叶片的保水能力，增强各种生理活动，并能稳定膜结构和维持膜完整性等方面起着重要的作用，从而提高棉花的抗旱性。     

钙处理对杨桃果实采后生理生化变化的影响

通过用ＣａＣｌ２溶液对甜杨桃果实进行真空浸渗处理，结果表明：１．低浓度Ｃａ处理（０．０２５ｍｏｌ／ＬＣａＣｌ２）抑制杨桃果实采后生理生化变化的效果不明显；２．高浓度Ｃａ处理（０．１５ｍｏｌ／Ｌ和０．２ｋ０ｍｏｌ／Ｌ ＣａＣｌ２）能显刺激杨桃果实采后生理生化的变化；３．适当浓度的Ｃａ处理（０．０５ｍｏｌ／Ｌ和０．１０ｍｍｏｌ／ＬＣａＣｌ２）能显抑制杨桃果实采后呼吸、乙烯释放，减少可溶性固形物、还     

固定化多酚氧化酶的化学性质研究

本文研究了固定化多酚氧化酶的性质，结果表明茶叶多酚氧化酶经包埋交联固定化以后贮存稳定性增加，最适ｐＨ在移至７．０，最适温度上升至４０℃，酶对金属离子（Ａｌ＾２＋，Ｃｕ＾２＋）适应性增强，对抑制剂敏感性下降。     

干旱胁迫下钙对裸大麦叶片生理生化特性的影响

利用盆栽试验研究了ＣａＣｌ２叶片喷施对干旱胁迫下裸大麦叶片若干生理生化特性的影响。结果表明，叶面喷１０ｍｍｏｌ／ＬＣａＣｌ２能使裸大麦叶片相对含水量和水势下降，气孔阻力增大，蒸腾强度减小，叶绿素含量和光合速率减小，ＳＯＤ、ＣＡＴ和ＰＯＤ活性增加，质膜透性降低。叶面喷钙处理后这些指标比对照下降或增加的幅度小，这说明钙处理提高了干旱胁迫下裸大麦叶片的保水能力，增强了各种生理生化活动，从而提高了裸大麦抗旱能力。     

Ca2+对水分胁迫条件下芒果叶片膜脂过氧化及膜保护系统的影响

以芒果幼苗为材料,研究Ｃａ２＋对水分胁迫条件下,叶片膜脂过氧化和膜保护系统的效应。结果表明：与对照叶片相比,涂施Ｃａ２＋后,叶片含水量、超氧化物歧化酶（ＳＯＤ）活性及Ｖｃ含量下降明显减慢;过氧化物酶（ＰＯＤ）活性上升加快且幅度加大,而下降延迟;丙二醛（ＭＤＡ）积累显著减少。Ｃａ２＋专一性螯合剂ＥＧＴＡ可削弱Ｃａ２＋的效应。ＣａＭ 拮抗剂氯丙嗪（ＣＰＺ）对叶片ＳＯＤ活性和ＰＯＤ活性有抑制作用,推测Ｃａ２＋可能通过与ＣａＭ结合调节相关酶活性,从而减轻水分胁迫对膜的伤害。      

花生RAPD反应条件的研究

在ＲＡＰＤ反应中,有许多因素影响结果的稳定性和准确性,本文以花生为材料,对ＲＡＰＤ各种反应条件的优化组合进行了探索。结果表明,花生ＲＡＰＤ的较为理想的反应体系如下,１０μｌ反应体积中含;５０ｍｍｏｌ／Ｌ ＫＣｌ,１０ｍｍｏｌ／ＬＴｒｉｓ－ＨＣｌ（ｐＨ９．０）,０．１％Ｔｒｉｔｏｎ－１００,２０￣４０ｎｇ引物,０．２ｎｍｏｌ／μｌ的ｄＮＴＰｓ,１￣２μｇ／μｌ的ＢＳＡ,１５ｎｍｏｌ／μｌＭｇＣｌ２０     

钙浸种对小麦幼苗保护酶活性及膜功能的影响

小麦种子用０．２５％ＣａＣｌ２浸种１８ｈ后，能减缓水分胁迫时期对幼苗的伤害，增强抗旱性，种子经过Ｃａ＾２＋预处理后，在水分胁迫条件下，体内超氧化物岐化酶，过氧化氢酶和过氧化物酶的活性强度比用蒸馏水预处理的高，并能减少丙二醛小麦叶片叶的积累。     

龙眼幼苗镁素吸收特性研究

龙眼镁素吸收曲线、电子探针分析以及代谢抑制剂对龙眼镁吸收影响等三方面的研究结果表明,龙眼镁素吸收特性取决于介质供镁状况,供镁浓度低（≤０．４０ ｍｍｏｌ／Ｌ）时,龙眼对镁的吸收受代谢控制,属主动吸收;供镁浓度高（＞０．４０ ｍｍｏｌ／Ｌ）时,属被动吸收。 Ｋ＋、Ｃａ２＋对镁的吸收有明显的抑制作用,但其机制并不相同。 Ｋ＋抑制 Ｍｇ２＋的吸收作用不是由于与Ｍｇ２＋竞争载体,而是Ｋ＋引起Ｍｇ２＋载体蛋白发生变构作用;Ｃａ２＋对Ｍｇ２＋吸收的影响可能与膜透性的改变有关。     

钙处理对盐胁迫下大豆种子萌发及其生理生化指标的影响

试验了不同浓度的ＣａＣｌ２，Ｃａ（ＮＯ３）２和ＣａＳＯ４三种钙盐对大豆生长前期盐胁迫的缓冲效应，结果表明：ＣａＣＬ２，ＣａＳＯ４都有明显的缓解作用，其中以１５ｍｍｏｌ／Ｌ，ＣａＣｌ２的缓解效果最佳。     

水稻属间远缘杂交种生育后期冠层叶片衰老特性的初步研究

】１９９２～１９９４年，在早晚季玻璃网房盆栽条件下对用远缘花粉诱变植物生态育种技术育成的属间杂种后代稳定品种远诱１号及其水稻亲本品种圭６３０，三系杂交水稻组合汕优６３灌浆成熟期冠层叶片的衰老特性进行了比较研究，用叶绿素含量及过氧化物酶（ＰＯＤ）的叶位间差异，对比于穗部成熟度的叶片早衰老指数（ＡＩ）为指标比较了属间远缘杂交种、品种间三系杂交组合、常规水稻品种生育后期叶片衰老特性的差异，解释了超大穗型品种远诱１号结实性良好的生理基础     

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。     

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％。     

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.     

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。     

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。     

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...