水稻同核异质不育系材料对白背飞虱抗性的研究初报

采用蜜露量测定法,初步研究了具有不同胞质的水稻同核异质不育系对白背飞虱的抗性反应。试验结果表明,具有D型不育胞质的不育系国广5A明显抗白背飞虱。     

水稻抗白背飞虱的资源发掘及其抗性遗传分析

 经过严格的抗性鉴定筛选,发掘出6个白背飞虱抗源材料，即石崖粘、白秆糯、Nabeshi、IR64、Rathu Heenati。 经抗性遗传分析,明确了6个抗源中4个国内品种对白背飞虱的抗性遗传方式。 石崖籼和5006携带单显性抗白背飞虱基因,抗性为显性遗传;白秆糯 和Nabeshi携带单隐性抗白背飞虱基因,抗性为隐性遗传。     

不同类型水稻品种对白背飞虱忌避性、抗生性和耐害性的测定

 研究了19个不同类型的水稻品种对白背飞虱的忌避性、抗生性和耐害性的测定。4个粳稻品种(91-17、丙90-98、丙850和丙93-63对成虫表现出较强的忌避性,丙93-63对白背飞虱产卵具有明显的忌避性。协优9308和春江06对白背飞虱的抗生性最强,协优413对白背飞虱具有一定的抗性。     

中国水稻品种对白背飞虱的抗性

评价了来自中国的13个粳稻品种、11个籼稻品种、13个杂交稻组合,以及11个热带粳稻品种的杀卵作用和拒食抗性.具有杀卵作用的品种仅见于粳稻品种.测试的13个粳稻品种中,4个表现出明显的杀卵作用.重新评价了来自中国不同省份的42份粳稻和43份籼稻对白背飞虱的抗性.10个粳稻(约占24%)具有杀卵抗性,卵死亡率为53%～100%;95%以上的籼稻品种中,白背飞虱的卵死亡率低于30%;来自浙江的4个粳稻品种明显地抑制白背飞虱的取食.浙江的21个粳稻地方品种对白背飞虱拒取食和杀卵作用表现出独立性和连续变化.三千黄、长红稻和矮秆稻具有杀卵抗性,鸡脚黄和麻雀青具有拒取食抗性.这些发现表明抗白背飞虱基因在中国存在于同一生态区的粳稻地方品种中.     

混植水稻抗虫和感虫材料抑制白背飞虱发生的初步研究

以与浙辐802成对的、具有Rathu Heenati抗白背飞虱基因的近等基因系"浙抗",以及以2∶1比例混合"浙抗"与浙辐802种子构成的抗-感白背飞虱混合群体"浙混"为材料,采用田间白背飞虱的种群调查和水稻产量及千粒重的测定,结合室内蜜露量、产卵量和卵发育率的测定,研究了混植抗感白背飞虱近等基因系材料对白背飞虱的控制效果.试验结果表明,"浙混"上的成虫及若虫数量均与在抗虫的RHT和"浙抗"上的相近,分别是在感虫的浙辐802和TN1上的1/2和1/4～1/5.白背飞虱在"浙混"和"浙抗"上分泌的蜜露量分别为9.03和6.97 mg/♀*d,显著地低于在浙辐802(17.64 mg/♀*d)和TN1(19.14 mg/♀*d)上的.白背飞虱在"浙混"与"浙抗"、浙辐802与TN1上的产卵量和卵发育率都没有显著性差异.与"浙抗"相比,"浙混"和浙辐802的稻谷产量分别增加了1.17%和减少了19.11%,"浙混"和浙辐802的千粒重分别减少了2.57%和9.84%.因此,混植抗感白背飞虱水稻材料可以有效地抑制白背飞虱的发生,还可以保证水稻产量不受损失.     

水稻品种对白背飞虱的抗性及其与稻株营养成分的关系

 研究了6个水稻品种在不同苗龄对白背飞虱的抗性与稻株营养成分的关系。结果表明、抗性品种 ARC10239、Rathu Heenati(RH)和中抗品种 N22、Mudgo 对白背飞虱的取食、存活和产卵有抑制作用:品系9101虽适宜于白背飞虱的取食和存活,但自孕穗期后严重影响其产卵。分蘖期后,品种抗性随苗龄增加而逐渐增强.这种趋势在中抗品种 N22和 Mudgo 上特别明显。稻株营养成分测定显示出稻株内的总氮和游离氨基酸(主要是亮氨酸和丙氨酸)的含量与品种抗性呈显著负相关。     

国际水稻所又发现水稻抗白背飞虱的一个显性基因

白背飞虱(Sogatella FurciferaHorvath)是危害热带和亚热带水稻的一种主要害虫。稻飞虱的防治措施,过去主要依靠化学药剂,但由此造成残毒、环境污染、害虫抗药性、杀伤天敌和增加成本等问题。因此,国际水稻所提出防治的战略是开发具有抗虫害基因的种质。目前该所种质库已筛选出抗白背飞虱的水稻品种400多个,并于1976年率先开展水稻栽培品种抗白背飞虱的遗传研究。迄今已发现4个抗性基因,其中有3个为显国基性,命名为Wbphl, Wbph2和Wbph3;第4个为隐性基因,命名为Wbph4。最近又鉴定出一个新的抗白背飞虱的显性基因,被命名为Wbph5。 自背飞…     

白背飞虱在抗感稻株上分泌蜜露的氨基酸成分分析

白背飞虱吸食水稻植株的韧皮部,影响其正常生长。近年来,由此而引起的水稻产量损失愈加明显。推广种植抗虫品种有效地阻止了飞虱在其上取食与建立种群,在防治此虫中发挥了十分重要的作用。水稻抗虫品种对白背飞虱产生的不良影响是多方面的。为了探索稻株韧皮部内营养成分对飞虱的影响,我们采用间接的方法分析了飞虱取食抗感稻株后分泌的蜜露中氨基酸的成分与含量。1 材料与方法1.1 蜜露的收集测定蜜露中游离氯基酸总量时选用的抗白背飞虱     

两个杂交稻组合及其亲本材料对白背飞虱抗性的研究

采用田间白背飞虱种群调查和水稻产量、室内白背飞虱蜜露量、产卵量及卵发育率测定,在浙江富阳和重庆秀山两地研究了杂交稻组合及其亲本材料对白背飞虱的抗虫性.田间试验结果表明不育系协青早A和珍汕97A表现出对白背飞虱比感虫对照品种TN1更感虫的"超感虫性",稻株上的若虫量分别高达371.1和292.5只/丛.在杂交稻汕优63和协优9308上的若虫数量与TN1上的相当,杂交稻的感虫性主要来源于其不育系亲本.在无杀虫剂防治的情况下,感虫杂交稻组合的千粒重和产量损失率高达22%和78%左右,不育系材料被完全毁灭,表现为虫量越大,千粒重下降幅度越大,产量损失率越高.蜜露量测定表明,恢复系明恢63和9803具有一定的耐虫性.白背飞虱在杂交稻及其亲本上的产卵量和卵发育率没有显著差异.还对杂交稻抗虫性的改良进行了讨论.     

不同施氮水平下水稻植株在白背飞虱为害后的生理变化

【目的】为明确不同施氮水平调控水稻对白背飞虱抵御能力的生理机制,【方法】采用室内笼罩饲喂胁迫法,比较了不同施氮水平下水稻受白背飞虱为害后,体内叶绿素(SPAD)含量、含水量、伤流液含量和干物质含量、可溶性糖含量等防御相关物质含量的变化。【结果】水稻受白背飞虱为害后,水稻体内不同防御物质含量变化存在差异。水稻受白背飞虱为害后体内叶绿素含量、干物质含量、可溶性糖含量均有所下降,伤流液含量、相对含水量、含水量有所上升。随着水稻施氮水平的增加,受害水稻叶绿素含量、干物质量降幅呈上升趋势,含水量、伤流液含量增幅呈上升趋势,相对含水量、可溶性糖含量增幅呈下降趋势。【结论】不同施氮水平可通过调控水稻体内叶绿素含量、相对含水量、含水量、干物质含量、可溶性糖含量影响水稻对白背飞虱的抵御能力,从而影响白背飞虱种群数量。     

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.     

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。     

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。     

玉米产量性状配合力遗传分析

通过对8个中晚熟玉米自交系产量性状进行双列杂交分析，表明各个自交系产量性状的一般配合力与特殊配合力存在显著差异，玉米杂交种F₁的产量构成受到一般配合力与特殊配合力的共同作用，用特殊配合力对F₁的作用大于一般配合力。特殊配合力高低与一般配合力无明显相关关系。因此在玉米杂交种组配与自交系改良工作中，既要兼顾双亲的一般配合力与特殊配合力，又要保持杂交优势利用模式与选系模式的种质关系。     

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.     

马铃薯黑痣病菌生物学特性测定

马铃薯黑痣病是土传真菌性病害,在定西市马铃薯种植区均有发生,目前已成为影响马铃薯产量和品质的主要因素之一。本研究对马铃薯黑痣病菌从温度、光照、碳源、氮源以及p H方面进行了生物学特性的测定。结果表明:该病原菌菌丝在无光25℃条件下生长最快,在无光35℃条件下生长最慢;室温条件下培养1 d后用紫外线照射处理2 h,然后室温持续光照培养4 d的菌丝生长速率最大,持续黑暗培养4 d的菌丝生长速率最慢;不同碳氮源对该菌菌丝生长均有影响,碳源为淀粉的培养基上菌丝生长最快、氮源为尿素的培养基上菌丝生长最快;培养基p H中性时菌丝生长速率最大。     

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％。     

Valorization of three varieties of grape

In the present investigation, seed methanolic extracts of three Vitis vinifera (Muscat d’Italie, Syrah and Carignan) were assayed for their antioxidant activities. Results showed that there are strong variations in the contents of total phenols (440.97–121.94 mg GAE g⁻¹ DW), flavonoids (48.07–16.81 mg EC g⁻¹ DW) and tanins (37.15–14.9 mg EC g⁻¹ DW) from the studied seeds. The phenolic composition of these extracts was determined by RP–HPLC after acid hydrolysis. The main phenolic compound was quercetin with 27.2% in Muscat d’Italie, 48.8% in Syrah and 28.4% in Carignan. Besides, all seed extracts showed remarkable DPPH radical scavenging activity with IC₅₀ values ranged from 1.8 to 30 μg ml⁻¹. EC₅₀ values of reducing power activity ranged from 100 to 120 μg ml⁻¹. The high phenolic content and the considerable antioxidant activities of vitis seed extracts could potentially be considered as an expensive source of natural antioxidants.     

几个粳稻不育系、恢复系产量性状配合力研究

新粳型不育系和恢复系是通过籼粳交或粳粳交的方式培育而成的中间型稳定品系,杂交组合的育性正常或接近正常。粳型不育系和恢复系配组,杂种F1的产量性状差异显著或极显著。组合9512A/R364、73A/R55、150A/R198、9512A/R2690、150A/R55,具有产量的正向超亲、超标优势,另一些组合呈显著或极显著的负向优势;本研究产量性状一般配合力好的不育系是中14A、辽150A、73A、9512A、9214A,恢复系是R198-2、R238、R46、C418、R364和花38;亲本的产量性状一般配合力和特殊配合力在不同性状的作用没有交叉。杂种优势的表现与双亲亲和力高低、配合力高低有明显的相关性。辽150A、9512A的超亲优势明显,R198、R55、R2690、R364、C204等恢复系具有较强的杂交优势。不育系对产量性状的作用显著大于恢复系。     

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.