芝麻白绢病病原菌的分离鉴定及其生物学特性研究

为了明确芝麻白绢病的病原菌,采用常规组织分离法对该病的病原菌进行分离,依据柯赫法则、形态特征及核糖体基因内转录间隔区（rDNA-ITS）序列对病原菌进行鉴定,同时检测其部分生物学特性。结果表明：引起芝麻白绢病的病原菌为罗氏阿太菌Athelia rolfsii （无性世代：齐整小核菌Sclerotium rolfsii）;该菌适宜生长温度为22 ~ 34℃,最适生长温度为31℃;在pH4.0 ~ 9.0 范围内均可生长,以pH 6.5 ~ 7.0 生长最好,表明微酸性至中性环境最有利于菌体生长;该菌虽能利用供试的13种碳源和8种氮源进行营养生长,但在以可溶性淀粉、蔗糖、葡萄糖、麦芽糖、L-阿拉伯糖和菊糖作为唯一碳源并配以硝酸盐为氮源的生长条件下不产生菌核,而在以葡萄糖为碳源并配以铵盐为氮源的生长条件下可产生菌核。与合成培养基相比,A. rolfsii在天然培养基上生长好于合成培养基,可形成更多、更大的菌核。       

温郁金白绢病菌的生物学特性及药剂毒力测定

为明确温郁金白绢病菌(Sclerotium rolfsii)的生物学特性及对杀菌剂的敏感性,本实验研究了不同培养条件对病原菌菌丝生长和菌核形成的影响,并测定了10种杀菌剂对病原菌的抑制作用。结果表明,该菌菌丝生长和菌核形成的最适温度范围为30~32℃,适宜p H范围为5~7,适宜培养基为燕麦和玉米培养基;持续黑暗有利于菌丝生长,光暗交替有利于菌核形成;不同碳源和氮源对菌丝生长和菌核形成的影响差异显著,其中蔗糖和硝酸钠分别为最适碳源和氮源;菌丝和菌核致死温度分别为50℃和55℃。烯唑醇对该菌的抑制作用最强,EC50为0.1412 mg/L;其次是吡唑醚菌酯、苯醚甲环唑和氟硅唑;而代森锌和百菌清的抑制作用最差,不适合用于防治温郁金白绢病。     

环境因素对禾谷丝核菌菌核形成的影响

为了探讨影响禾谷丝核菌(R.cerealis)菌核形成的主要因素,在不同温度、培养基酸碱度、光照、碳氮营养等条件下对R.cerealis的生长状况和菌核形式进行了观察和分析.结果表明,温度、pH值、光照、碳氮营养对R.cerealis菌核的形成均有极显著影响.R.cerealis菌核形成的适宜温度为18～25℃,适宜pH值为5.0～7.0,暗培养或光暗交替培养有利于菌核形成;在碳、氮营养中,葡萄糖和NO-3-N最有利于R.cerealis菌核的形成,L-脯氨酸和L-亮氨酸可抑制菌核形成,但对菌丝生长无不良影响.     

环境因素对禾谷丝核菌菌核形成的影响

为了探讨影响禾谷丝核菌（R．cerealis）菌核形成的主要因素,在不同温度、培养基酸碱度、光照、碳氮营养等条件下对R．cerealis的生长状况和菌核形式进行了观察和分析。结果表明,温度、pH值、光照、碳氮营养对R．cerealis菌核的形成均有极显著影响。R．cerealis菌核形成的适宜温度为18～25℃,适宜pH值为5．0～7．0,暗培养或光暗交替培养有利于菌核形成;在碳、氮营养中,葡萄糖和NO3^--N最有利于R．cerealis菌核的形成,L-脯氨酸和L-亮氨酸可抑制菌核形成,但对菌丝生长无不良影响。     

大豆菌核病菌生物学特性的研究

为有效控制大豆菌核病的发生、蔓延,从采自黑龙江省不同地区大豆菌核病菌中选取5个代表性菌株进行生物学特性的研究.结果表明:大豆菌核病菌菌丝生长的最适温度为20 ～ 25℃,而菌核在15 ～20℃时产生量最多;菌丝适于在中性和偏酸性条件下生长.病菌在PDA和大豆叶片汁培养基上生长较好,菌核的产生则在向日葵叶片汁培养基上最多;有无光照对菌丝生长影响不大,但光照有利于菌核的产生.子囊孢子萌发最适温度为25℃;萌发最适pH为7～8;大豆汁、向日葵汁和油菜汁可促进子囊孢子的萌发;有无光照对子囊孢子萌发无显著影响.不同地区大豆菌核病菌由于生态条件的不同,菌核萌发形成子囊盘能力和病原菌的致病力也存在差异.     

香茅纹枯病病原菌的分离鉴定及其生物学特性

对香茅纹枯病病原菌进行分离鉴定及其生物学特性研究。结果表明：香茅纹枯病病原菌为立枯丝核菌(Rhizoctonia solani Kühn)；其最适生长培养基为马铃薯葡萄糖琼脂培养基，最适pH值为8，在可溶性淀粉为碳源的查彼克琼脂培养基上生长最快，在麦芽糖为碳源的查彼克琼脂培养基产菌核最多；该病原菌生长对氮源有一定偏嗜性，一般应在其分离培养基内添加硝酸钾作氮源；最适培养条件为25～30℃，全光照。寄主范围测定表明，人工接种该病原菌能侵染花梨木(Dalbergia odorifera T.Chen)、大叶桃花心木(Swietenia macrophylla King.)、虎刺梅(Euphorbia milii var． splendens (Bojer ex Hook.) Ursch)、玉米(Zea mays L.)、水稻(Oryza sativa L.)、新台糖22号糖蔗(Saccharum officinarum L.T22)和果蔗(Saccharum sinense L. Home.)、雨树(Samanea saman(Jacq.)Merr.)、普通烟(Nicotiana tabacum L.)、发财树(Pachira aqualica Aubl)等10种盆栽植物幼苗。     

辽宁花生纹枯病病原鉴定及其生物学研究

本文对辽宁花生纹枯病病原学进行了较为系统的研究。根据病原菌形态学特征及致病性测定,明确辽宁花生纹枯病病原菌为立枯丝核菌(Rhizoctonia solani)。病原菌生物学特性研究发现该菌最适pH值为7.0;该菌能利用供试的6种碳源和5种氮源进行营养生长,在尿素作为唯一氮源的培养基上菌丝不生长并且不产生菌核,其余碳氮源培养基均产生菌核;该菌在玉米粉和PDA培养基上生长最好;光照对菌丝的生长及菌核的产生影响不大。     

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。     

红毛丹炭疽病菌生物学特性研究

对红毛丹炭疽病病菌进行分离,鉴定病原菌为胶孢炭疽菌[Colletotrichum gloeosporioides(Penz.)Sacc.]。研究培养基、温度、湿度、pH值、光照、营养对红毛丹炭疽病菌生长和孢子萌发的影响。结果表明,该菌菌丝在PDA、CA和CZ培养基上生长较好,10~35℃下均能生长,适宜生长温度为25~28℃,分生孢子萌发的最适温度为28℃;病原菌在pH3~11都能生长,pH5~8生长较好,菌丝生长及孢子萌发最佳pH值为7;分生孢子在饱和湿度中萌发快,相对湿度低于99%时不能萌发;光照对病原菌的生长有明显的促进作用,病原菌的致死温度为:55℃,10min;PDA培养基中加入不同的糖对病原菌生长有明显的促进作用,以鼠李糖、果糖、半乳糖、麦芽糖、甘露糖和木糖最好;PDA培养基中添加2%的不同的无机氮源对病原菌的生长有明显的促进作用。     

油菜黑胫病菌（Leptosphaeria biglobosa）生物学特性研究

为了解我国油菜黑胫病病原菌（Leptosphaeria biglobosa）的生物学特性,在实验室里研究了温度、pH值、光照、碳源及氮源等条件对该病菌营养生长及分生孢子产生的影响。结果表明：病原菌在5℃～35℃均可进行营养生长并产孢,最适生长和产孢温度为25℃;在pH4～10的范围内该菌均能生长并产孢,在pH7的条件下生长最快,产孢最多。光暗交替有利于菌丝生长和产孢,而持续光照不利于菌丝生长,尤其不利于产孢。最适的碳源、氮源分别是可溶性淀粉、牛肉膏。分生孢子的致死温度为52℃。     

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.     

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.     

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。