Abstract:采用NCⅡ设计,对选自国外玉米杂交种的5个不同株系(同一二环系)在不同密度环境条件下的杂种优势和配合力进行了研究.结果表明:在4.5、6.0和7.5万株·hm-2密度下玉米单株产量的杂种优势均较高,为116.4%、77.2%和48.7%,其杂种优势随密度增加而减小;这5个自选系与塘四平头、旅大红骨系统杂交,单株产量具有较强的杂种优势,在4.5、6.0和7.5万株·hm-2密度下选出的高杂种优势组合中,其所配组合分别占4/6、7/8和6/8;自选系和骨干系的一般配合力在不同密度下表现不同,同一自选系的特殊配合力在不同密度下表现亦不同;单株产量的一般配合力在6.0和7.5万株·hm-2时变化趋势相近,呈显著正相关.

Abstract:The seed coating and phosphorus application experiments were done using three tobacco varieties,including K326,Yunyan85 and Honghuadajinyuan.The results showed that the seed coating could not only improve greatly seed germination rate,but also shorten seed germination time.But seed coating treatment had no obvious effects on tobacco biomass and total root length.And tobacco seed coating had nutrients not also increased the accumulation of macro-nutrients,including nitrogen,phosphorus and potassium,in tobacc...

Abstract:A pot experiment was carried out to study the effects of different composts with different maturities and inoculation on tomato growth and soilborne disease suppression in the greenhouse.The regulating functions of different composts on soil microbial community were studied by Biolog method.The results showed that all composts could increase the plant height and biomass obviously,and the disease severity was reduced.The effect of two-time inoculated compost on controlling bacterial wilt was better than thos...

Abstract:Streptomyces strain 4301 was isolated from the soil.Metabolites produced by this strain showed fungicidal activity.The diameter of inhibitory cycles of Peronophythora litchii affected by Streptomyces strain 4301 was 25.5 mm in solid culture.Optimal fermentation conditions and medium of liquid culture for Streptomyces strain 4301 were investigated.The results indicated that the optimal fermentation medium and conditions were as follows:glucose 2%,soluble starch 2%,beancake powder extract 3%,protose peptone 0...

Abstract:The heavy metals pollution on soils and vegetables for some sewage-irrigated vegetable bases in the suburb of Foshan were investigated.The results showed that the heavy metal contamination in soils of the suburb of Foshan was serious.The contents of Hg and Cd exceeded 93.88% and 12.24% respectively in the collected soil samples,comparing to the Grade II limited values of the national soil environment quality standard.The comprehensive pollution indexes of 77.5% of the soils were greater than 1.The leaf vege...

Abstract:Cotton stalk vinegar and miscellaneous wood vinegar had been analyzed comparatively.Their wood vinegar composition was detected by GC/MS mainly.The major components of the two wood vinegar were acids,ketenes,phenols,alcohols,and other organic materials.There were 30 and 41 kinds of components respectively in cotton stalk vinegar and miscellaneous wood vinegar,but other organic materials were less than in miscellaneous wood vinegar.Physical and chemical indicators showed that the color of cotton stalk vinega...

Abstract:The results from systematical investigation in field indicated that the migration regularity of the population of rice planthoppers Nilaparvata lugens and Sogatella furcifera kept temporal consistency in different resistant rice varieties.The N.lugens populations were different between two sensitive rice growth stages before northward migration,and aggregated in boot stage at the end of June and migrated to mid-tillering stage in early and middle July,however the maximal population of southward migration on...

Abstract:The index of dispersion(C) and probability distributions fitting were applied to study the spatial pattern of nymphs of Fruhstorferiola tonkinensis in mulberry field.The results showed that the spatial distribution patterns were aggregated in all instars of the nymph.The dispersion indexes of the nymphs were 879.578,152.742,22.972,6.053 and 6.150 from the 1st to 5th instar,respectively.The spatial distribution pattern of the 1st to 3rd instar nymphs were fitted to Neyman type A distribution,and the 4th and ...

Abstract:The reproduction biology of Diachasmimorpha longicaudata was studied by construction of experimental population life table of D.longicaudata reared in oriental fruit fly,Bactrocera dorsalis.D.longicaudata had a pro-oviposit period for 1 to 3 days,depending on adult's food and copulation.The peak of reproduction activity appeared in 4 to 10 days after adult emergence,and one female could breed about 125 offspring,however,the number of daily parasitized larvae of D.longicaudata was no more than twenty.The net...

Abstract:One set of the conserved primers was designed to amplify a 1 853 bp fragment which included 16S rDNA(1 527 bp),adjacent spacer sequence(234 bp) and partial sequence of 23S rDNA(92 bp) by PCR from total DNA sample extracted from diseased rice as the amplified template.Nucleotide sequencing of the amplified fragment indicated that rice orange leaf phytoplasma shared nucleotide similarity about 88% to 95% with other phytoplasmas from data of GenBank,and a maximum similarity at 95% with America aster yellow phy...

Abstract:采用生长速率法测定了岗松Baeckea frutescens等13种植物乙醇提取物对芒果炭疽病菌Colletotrichum gloeos-porioides、香蕉炭疽病菌C.musae、香蕉枯萎病菌Fusarium oxysportan、草莓灰霉病菌Botrytis cinerea和黄瓜炭疽病菌C.orbiculare的抑菌活性.结果表明,在10 mg·mL-质量浓度下处理96 h,马尾松Pinus massoniana乙醇提取物(浸膏)对香蕉炭疽病菌和香蕉枯萎病菌抑菌率均达到100%;岗松乙醇提取物对5种病原菌抑菌率分别为96.53%、90.20%、90.55%、89.63%和62.59%;四季米仔兰Aglaia duperreana和阴香Cinnamomum burmani的乙醇提取物对黄瓜炭疽病菌抑菌率也在80%以上.岗松精油对以上5种病原菌的EC50分别为:0.104 7、0.137 3、0.122 6,0.046 9和0.126 2 mg·mL-1,抑菌效果显著,且具有广谱的抑菌活性.

Abstract:Sixteen endophytic fungi belonging 10 genus were isolated from Derris hancei Hemsl.The antagonism of endophytic fungi against fungal pathogens was tested in vitro.Penicillium sp.Q1,Rhizoctonia sp.S1,Phomopsis sp.N2,and Corticium sp.F1 isolated from the caudex of D.hancei,and Penicillium sp.Q2 isolated from the leaf,inhibited the hyphal growth of Colletotrichum gloeosporioides Penz,Fusarium oxysporum f.niveum(E.F.Smith)Snyber et Hansen,Rhizoctonia sp.S1 against Colletotrichum orbiculare Arx,and Phomopsis sp....

Abstract:以杀虫剂溴虫腈为起始原料,合成了半抗原4-溴-2-(对氯苯基)-1-乙氧基甲基-5-(三氟甲基)吡咯-3-甲胺(简称CFP-NH:).通过戊二醛法将该半抗原分别与牛血清白蛋白(BSA)和卵清白蛋白(OVA)进行偶联得到全抗原,经紫外光谱法鉴定后,用三硝基苯磺酸法(TNBS)测得2偶联物偶联比分别为22:1和15:1.以CFP-NH2-BSA免疫新西兰白兔、CFP-NH2-OVA为包被原,对其抗血清进行间接竞争酶联免疫吸附测定(ELISA),测得抗血清效价为2.56×104,抗血清竞争性抑制试验表明,溴虫腈质量浓度为40 μg/mL时,其抑制率达80%以上,进一步证明抗原合成成功.

Abstract:通过收集皮暗斑螟Euzophera batangensiz的处女雌蛾和雄蛾,提取雌蛾性腺分泌物,在室内通过气相色谱与触角电位测定相结合的方法,测定皮暗斑螟雄蛾对来自雌蛾性腺的不同化合物的反应,并应用全二维气相色谱飞行时间质谱分析技术(GC×GC/TOFMS),弄清了皮暗斑螟性信息素组分为(Z9,E12)-十四碳-9,12-二烯-1-醇和(Z9)-十四碳-9-烯-1-醇.研究过程发现,GC×GC/TOFMS与传统气相色谱质谱(GC-MS)分析相比,灵敏度和精度更高,可以达到0.01 ng/μL,在昆虫信息素的研究中具有更大的优势.

Abstract:The noctuid genus Ugia from China was briefly noted,Ugia sundana was recorded in China for the first time.Up to date,three Ugia species have been known in China.Male adult and genitalia of Ugia sundana and Ugia purpurea,as well as venation of Ugia purpurea,were illustrated.

Abstract:从广东省韶关市大宝山矿区土壤中,分离得到1株耐酸耐盐菌株Huanghu3,经形态鉴定及18S rDNA序列分析确定为青霉菌Penicillium sp..对其生理生化特性、产纤维素酶培养条件和酶学特性的研究表明,Huanghu3能分别在pH 2.8和含200.0 g·L-1NaCl的培养基中生长,说明Huanghu3是一株具较强耐酸耐盐特性的菌株.产酶优化培养条件为:玉米秸秆粉作为培养基碳源,(NH4)2SO4为氮源,培养基的起始pH为7.0,培养72 h最为适宜.该菌株产生的滤纸酶、Cx酶和C1酶最适反应温度分别在50～60、50～55和45～55℃,纤维素酶系活力最适反应在pH4.5～5.5.

Abstract:Identification of the 7 060 specimens collected in field surveys was made,and 120 species of rare and endangered plants in East Guangdong were found.There are 102 species of endangered species(IUCN),of which there are 2 critically endangered species,10 endangered ones,45 vulnerable ones,41 near threatened ones and 4 least concern ones.According to Red-Data Book of Plants in China,there are 22 rare and endangered plants in East Guangdong,of which there are 2 endangered ones,6 rare ones and 14 vulnerable spec...

Abstract:对广东省德庆县三叉顶自然保护区的生态公益林气温、相对湿度和太阳辐射进行了定位观测,以空旷地为对照,分析生态公益林的小气候效应.结果表明:在2006年8月和2007年5月典型晴天,生态公益林林地气温平均比空旷地气温分别低1.7和1.6℃,林地相对湿度平均比空旷地相对湿度分别高8.3%和2.2%,2006年8月和2007年5月典型晴天森林平均透射率分别为5.9%和7.7%;空旷地与林内的气温、相对湿度和太阳辐射相关性极显著,相关系数分别为0.979、0.879和0.889.

Abstract:One hundred and twenty 1-day-old parental male Arbor Acre(AA) broiler chicks were randomly divided into 4 replicates,respectively.Regional expression of CDX2 mRNA in different segments of intestinal tract of AA chicken on 30 d and ontogenetic expression of CDX2 mRNA in duodenum and jejunum of AA broiler chickens were determined by relative quantitative RT-PCR.It was found that: The CDX2 mRNA expression in duodenum was higher than that in jejunum(P=0.09),ileum(P=0.06) and colorectum(P=0.05),respectively.Onto...

Abstract:以健康的草鱼为试验对象,初始体质量(50.63±0.43)g,在室内[(22±3)℃]单循环控温养殖系统中进行8周生长试验,以鱼粉为动物蛋白源,去皮豆粕为植物蛋白源,去皮豆粕分别替代0%、15%、30%、45%和60%的鱼粉蛋白,配制成5种等蛋白(w=30%)等能(15.6 MJ·kg-1)的半精制饲料,探讨大豆蛋白对草鱼生长及饲料利用的影响.结果表明,草鱼的特定生长率(SGR)各组之间差异不显著(P>0.05);随着大豆蛋白替代水平的增加,饲料效率(FER)、蛋白质效率(PER)及蛋白质沉积率(PPV)逐渐增加,60%组开始下降,但仍显著高于对照组(P<0.05).因此,在此试验条件下,草鱼配合饲料蛋白水平为w=30%时,大豆蛋白替代鱼粉蛋白的最适宜量为45%.最大替代量为60%.过量添加大豆蛋白,将影响草鱼的生长及饲料利用.

Abstract:To study the effect of immunization of newcastle disease virus(NDV) F DNA vaccine with chicken IL-18 gene eukaryotic expression plasmid(pcDNA-chIL-18),F gene of NDV strain F48E9 was amplified by RT-PCR.The eukaryotic expression plasmid pcDNA-F(DNA vaccine) was constructed by inserting F gene into the pcDNA 3.1 vecter.11-day-old chickens were divided into 4 groups,10 chickens per group.14-day-old chickens were primarily immunized by injected intramuscularly and boosted immunized 14 days later after primary i...

Abstract:The histological,surface and internal fine structures of gill filaments of Cromileptes altivelis were investigated using light,scanning and transmission electron microscopy.The results showed that the surface structure and ultrastructure of gill filaments and secondary gill lamellae of C.altivelis were similar to those of other teleosts.Various features such as regular or irregular circular microridges,indentations,micropits and crevices were present.The arrangement of gills were tight,the terminal of gill ...

Abstract:应用Chelex-100快速提取动物基因组DNA的方法,并根据羊线粒体基因的核苷酸序列设计1对引物,通过对分离的DNA进行PCR扩增、基因克隆及核苷酸序列分析,实现了对动物源性饲料中羊组织成分的检测.结果显示,该方法对羊组织DNA检测的敏感性可达20.16 pg/μL,当肉骨粉样品中含有质量分数为0.050%的羊源性成分时仍能检出,整个过程约需3 h.

Abstract:Pathogeny or gE-Ab investigation of pseudorabies(PR),classical swine fever(CSF),porcine reproductive and respiratory syndrome(PRRS),porcine circovirus type 2(PCV2) showed that there were serious co-infections in farms of Guangdong from 2003 to 2004.There was a positive relation(P=0.012)between PR and PCV2,and the correlation coefficient was 0.648.This two disease were coinstantaneous in cross-spectrum analysis.There was weak connection between PCV2 and CSF.Prevalence of PCV2 will affect weakly on prevalence...

Abstract:This paper proposed one kind of K-Means analysis method based on the genetic algorithm by the average value niche.The real number method was used to encode the clustering center,and the chromosome was matched with the clustering central array correspondingly throuth array transformation.The method was used to update the clustering central with selection,crossover,mutation and the average value niche population optimization.The stable state of the error function and the best dividing clustering center was ob...

Abstract:With the disadvantages of traditional science and technology management system analyzed,an integrative science and technology management database was designed.Data mining,workflow and geographic information systems(GIS) technology were employed to study key problems in detail,such as workflow of project,map visualization,data mining and statistical analysis.Then,the science and technology management information system based on WebGIS was developed and constructed.

Abstract:利用Φ(t,s,r)型函数和Riecati技巧,建立了一类具有连续分布滞量的二阶非线性中立型微分方程的一些新的振动准则.

Abstract:Porcine reproductive and respiratory syndrome virus(PRRSV) variant strains(NSP2 1 594-1 680 deletion) were identified by real-time RT-PCR from boar semen of a pig farm.cDNA of NSP2 and ORF5 genes of one strain named GDTS were cloned and sequenced.The results showed that NSP2 gene was composed of 950 amino acids,which had 1 amino acid deletion at the positions of 481 and 29 amino acids deletion at the positions of 532-560 compared with that of CH-1a and VR-2332,which had the same deletion compared with that ...

Abstract:以纯化的新城疫病毒ND35免疫Balb/C小鼠,取免疫小鼠脾细胞与SP2/0骨髓瘤细胞融合.经筛选,获得5株能稳定分泌抗体的杂交瘤细胞株.特异性试验表明,7G5单克隆抗体仅与ND35病毒株反应,而不与禽流感病毒AIV(H5亚型)、产蛋下降综合症病毒(EDS-76V)、传染性支气管炎病毒(IBV)、传染性法氏囊病毒(IBDV)、马立克氏病毒(MDV)、禽肺病毒(APV)反应.通过Western-blot对7G5单克隆抗体进行鉴定,发现其在相对分子质量47 500～62 0130之间出现条带,表明其与NDV抗原有特异性结合.这5株单克隆抗体属于IgGl、IgG2b亚类,κ轻链.

Abstract:Vanilla shenzhenica Z.J.Liu et S.C.Chen was found to occur in Huizhou,Guangdong,China.This represents a new record of this species for Huizhou.A morphological description of the species is given based on the newly discovered population,which grows under a sparse mixed coniferous and broad-leaved forest on a stone cliff along a stream at an altitude of 400-500 m.The population is very big,consisting of many individuals.The locality of the population is not near village,and thus not easily accessible by human...

Abstract:Arbuscular mycorrhizal(AM) fungi can help plant to remedy the heavy metal-contaminated soil.In the present study,30 soil samples and the corresponding plant root samples were collected from Dabao Mountains,North Guangdong.The results revealed that the contents of Cu,Zn,Pb and Cd in 27 soil samples from contaminated areas exceeded the national standard at different levels.Following the staining of root samples and the observation for AM fungi colonization,81.5% of root samples from contaminated areas were fo...

Abstract:When the central door lock was locked unexpectedly and the keys were lost or locked in the car cab,the automobile diagnosis equipment could be used to enter the body control unit or turn on the air bag system running function.The central door lock would be opened finally and the automobile would not be damaged.

Abstract:A species,Asclepaidaceae,Hoya radicalis Tsiang et P.T.Li is reported as new records from Hainan,China.The specimens examined is preserved in Dendological Herbarium,College of Forestry,South China Agricultural University(CANT).