Effect of wheat (Triticum aestivum) cultivars and seeding rate on yield loss from Galium aparine (cleavers)

Galium aparine L. is a troublesome broadleaved weed in winter wheat fields and other winter-sown crops in Eurasia and North America. Field experiments were conducted in Havza and Kavak, Samsun-Turkey, to evaluate the effect of different densities of G. aparine on the productivity of four wheat cultivars and to determine the effects of different seeding rates of wheat cultivars on the competitive ability of G. aparine. In experiments over 3 years, the wheat cultivar Panda was taller at maturity than other cultivars at both sites. Although Bezostaja was naturally shorter than other cultivars, its height decreased less due to competition from G. aparine than other cultivars. Wheat grain yields increased with seeding rate, either in the presence or in the absence of G. aparine at both locations. Based on wheat yields the relative competitiveness of the wheat cultivars was Bezostaja>Momtchill=Panda>Kate A-l. G. aparine biomass and seed numbers were reduced by an increase in the wheat seeding rate and by cultivar effects.     

Toxicity of Acorus calamus rhizome powder from Eastern Nepal to Sitophilus granarius (L.) and Sitophilus oryzae (L.) (Coleoptera, Curculionidae)

Powders prepared from sweetflag Acorus calamus rhizomes collected at both high (1700 m) and low (900 m) altitude in Eastern Nepal were admixed with wheat at concentrations in the range 0.05–2% w/w and the wheat infested with Sitophilus oryzae or S. granarius adults. Following a 7 day incubation, the mortality of both species was significantly lower at 20 °C than at 30 °C, and the material collected from high altitude was slightly less toxic than that from low altitude. The moisture content of the wheat (14 or 17%) and the part of the rhizome used to prepare the powder (young or mature growth) had no apparent effect on the toxicity of the preparation. Sitophilus granarius (L.) adults were more tolerant of the material than S. oryzae (L.), while the converse was true for larvae developing in treated grain. An admixture rate of approximately 2% w/w admixed rhizome powder was required to give complete kill of adults of both species following 7 days exposure at 20 °C, while a concentration of 1% w/w either prevented the emergence of adults or killed them rapidly following emergence when wheat containing eggs of either species was incubated for 7–8 weeks at 30 °C.

The β-asarone content of the rhizome powders was determined by GC-MS as 6.4 and 4.7% w/w (mature section of rhizomes collected at high and low altitudes, respectively) and 3.6 and 4.0% w/w (young sections of rhizomes collected at high and low altitudes, respectively). It is anticipated that, under field conditions and in the temperature range 20–30 °C, the initial residue of approximately 1300 mg/kg β-asarone required to disinfest wheat containing these weevil species would decline rapidly due to evaporation.     

苦瓜果实S-腺苷蛋氨酸脱羧酶基因McSAMDC的克隆、表达及亚细胞定位

根据已构建苦瓜果实均一化文库中获得的1个与SAMDC基因相关的EST序列,采用3′RACE技术,克隆获得1个苦瓜SAMDC基因的cDNA全长序列,命名为McSAMDC(GenBank登录号为KC632099).生物信息分析结果表明,该cDNA全长l900bp,5′UTR和3′UTR分别长501、325bp.该cDNA序列存在3个开放读码框(微型tORF、上游读码框uORF和主读码框mORF),其中mORF长1077bp,编码358个氨基酸,预测分子量为39.31ku,含有酶原剪切位点结构域和蛋白快速降解有关的PEST二个保守结构域.二级结构分析显示,McSAMDC含有无规卷曲(45.53％)、α-螺旋(29.33％)、伸展链(19.83％)、β-转角(5.31％).序列分析结果表明,McSAMDC与拟南芥(CAA69073.1)、琴叶拟南芥(XP002882231.1)和雪里红(AAS45435.1)的氨基酸序列相似性分别达到69％、68％和68％.亚细胞定位结果表明,McSAMDC定位在细胞质中.荧光定量结果表明,McSAMDC在果实膨大期表达量最高,并随之迅速下降,并从成熟初期至完全成熟期该基因表达量逐渐增大.     

玉米ZmGly基因不同非生物胁迫下的表达特性与ZmGly1基因的克隆

植物乙二醛酶系统在清除非生物胁迫产生的甲基乙二醛(MG)中起着重要作用。玉米基因组中有3个编码乙二醛酶基因(ZmGly1、ZmGly2和ZmGly3)。利用qRT-PCR技术解析ZmGly在玉米不同组织器官和不同胁迫条件下的表达差异,克隆MG降解关键基因ZmGly1。结果表明,ZmGly1和ZmGly2在叶片中的相对表达量较高,ZmGly3在茎中的表达量较高。除涝害处理下表达量降低外,ZmGly1和ZmGly3叶片中的相对表达量在干旱、盐、高温和低温处理下均随处理时间的延长呈现先升高后降低的趋势;ZmGly2在所有胁迫处理下均呈现先升高后降低的趋势。测序结果表明,克隆到的ZmGly1片段大小及序列正确。ZmGly在不同器官中的表达不仅具有特异性,而且对不同非生物逆境胁迫的响应各异。     

Screening of allelochemicals on barnyardgrass (Echinochloa crus-galli) and identification of potentially allelopathic compounds from rice (Oryza sativa) variety hull extracts

Experiments were conducted to screen 23 known allelochemicals, including sinapic acid, and an equimolar mixture of the chemicals for potential allelopathy on barnyardgrass (Echinochloa crus-galli var. oryzicola), and to identify allelochemical(s) from hull extracts from three rice (Oryza sativa L.) cultivars. In a bioassay, the inhibitory effect was increased as the concentration of allelochemicals increased from 10⁻⁵ to 10⁻³ M. Ferulic, p-hydroxybenzoic, p-coumaric, and m-coumaric acids were the most active compounds and caused the greatest effect on seed germination, germination rate, and total seedling dry weight reduction. p-hydroxybenzoic acid (10⁻³ M; pH 4.1) showed the greatest inhibitory effect on the same parameters. HPLC analysis using three rice cultivars, Janganbyeo, Baekambyeo, and Labelle, showed that the concentration and composition of potentially allelopathic compounds depended upon the cultivar. Hull extracts from the allelopathic cultivar Janganbyeo contained higher levels of p-hydroxybenzoic acid than did those of the non-allelopathic cultivars Labelle and Baekambyeo. Nine compounds, including p-hydroxybenzoic acid (4.29 mg/g) in Janganbyeo, seven compounds including m-coumaric (0.43 mg/g) in Labelle, and five compounds including p-hydroxybenzoic acid (0.36 mg/g) in Baekambyeo, were detected. Preliminary identification by HPLC analysis resulted in peaks with retention times near those of standards, including p-hydroxybenzoic acid that was confirmed with EI/MS. It is suggested that these compounds may be, at least, a key factor in rice allelopathy on barnyardgrass, and the information presented may contribute to the development of naturally occurring herbicides.     

小麦EPF/EPFL基因家族的全基因组鉴定及 TaEPF1-2B与气孔性状的关系分析

表皮模式因子EPF/EPFL基因家族编码一类植物中特有的分泌类蛋白,在植物生长发育特别是形态建成过程中发挥着重要作用。为挖掘和利用小麦EPF/EPFL家族基因,对小麦该家族基因进行了系统鉴定,并利用生物信息学技术对其基因结构、蛋白质结构域、系统进化及表达特性进行分析。结果表明,在小麦全基因组水平共鉴定到35个TaEPF/EPFL基因家族成员,含有1~4个外显子,分布在除1A、5B外的19条染色体上,全基因组复制事件是导致该基因家族扩张的主要原因。蛋白结构分析显示,其编码蛋白的C端包含6个相对保守的半胱氨酸残基,N端存在信号肽剪切位点,且亚细胞定位在胞外基质中,属于一类胞外分泌蛋白。系统进化分析发现,TaEPF/EPFL基因在单子叶和双子叶植物分化之前就已形成。表达模式分析发现,大多数TaEPF/EPFL基因在小麦幼嫩组织和穗部表达量较高,部分TaEPF/EPFL基因响应干旱、高温等非生物胁迫。进一步分析 TaEPF1-2B不同单倍型与气孔性状的相关性,发现TaEPF1-2B不同单倍型的气孔密度、气孔长度、气孔宽度和气孔面积均存在极显著差异,净光合速率存在显著差异,其中单倍型Hap A具有较低的气孔密度和较高的光合速率,是优势单倍型。本研究结果为进一步改良小麦的抗旱性和光合效率提供了候选基因。     

小麦TaHTAS-5A基因的克隆、表达分析及亚细胞定位

非生物胁迫对小麦的生长发育具有不良影响,克隆与非生物胁迫相关的基因,并对其结构及表达特性进行分析,可以为进一步探索小麦的抗逆机制和抗逆育种奠定基础。本研究利用同源克隆技术从普通小麦品种中国春中克隆了水稻E3泛素连接酶基因OsHTAS的同源基因TaHTAS-5A(GeneBank登录号:MF967573),并利用生物信息学方法对其基因序列特征进行分析;利用qRT-PCR技术对该基因在小麦不同组织及不同逆境胁迫下的表达模式进行分析;同时,对该基因的表达产物进行了亚细胞定位。结果表明,小麦TaHTAS-5A基因含有220bp的5′UTR、1 242bp的ORF以及126bp的3′UTR,共编码413个氨基酸;基因组分析表明,该基因全长3 819bp,共包含4个外显子和3个内含子;缺体-四体定位表明该基因位于小麦5A染色体上;蛋白结构分析显示,TaHTAS-5A蛋白的N端包含四个跨膜结构域,C端包含一个E3泛素连接酶特有的RING finger保守结构域,具有植物E3泛素连接酶的结构特征;qRT-PCR结果显示,TaHTAS-5A对高温、低温和ABA都有响应,对干旱和盐响应不敏感;TaHTAS-5A在小麦的根、茎、叶和幼穗等不同组织中均有表达,但表达量有差异,在叶和穗中的表达量明显高于根部和茎部;亚细胞定位结果表明,TaHTAS-5A位于细胞膜上。本研究为进一步探究小麦TaHTAS-5A基因的功能奠定了基础,也为小麦非生物胁迫抗性改良提供了一定的理论依据。     

普通小麦TaADF8基因的克隆及表达分析

肌动蛋白解聚合因子(actin-depolymerizing factor,ADF)普遍存在于真核细胞中,为低分子量的肌动蛋白结合蛋白,在调控细胞内肌动蛋白纤维的聚合和解聚中起关键作用。为给深入研究TaADF8基因在小麦中的功能机理奠定基础,并为进一步丰富小麦ADF基因研究内容提供理论参考,本研究利用电子克隆策略从小麦品种CP53中克隆出TaADF8基因(GenBank登录号为KJ864962)后对其进行序列分析,并进一步采用荧光定量PCR(quantitative real-time PCR,qRT-PCR)技术对其在小麦不同组织间的表达差异及不同非生物胁迫下的表达模式进行分析。核酸序列分析表明,该基因全长695bp,拥有完整的ORF,编码142个氨基酸。氨基酸序列分析表明,该蛋白含有保守的ADF同源区和PIP2结合结构域,且在氨基端有核定位信号。进化和聚类分析表明,小麦TaADF8基因与大麦HvADF2基因、HvADF3基因和水稻OsADF3基因亲缘关系较近,蛋白相似度分别为75.35%、93.66%和67.86%。qRT-PCR表达特性分析显示,该基因为组成型表达,在根、茎、叶、颖壳和雄蕊中均表达,且在根、叶和雄蕊中表达量较高;该基因表达受低温的强烈诱导,同时也受水分、高盐和外源脱落酸胁迫诱导。     

小麦细胞色素P450(TaP450)基因的克隆与序列分析

细胞色素P450是一种多功能氧化酶,在植物体内担当着生物合成、代谢解毒以及抗逆等重要功能。本研究采用RACE方法从普通小麦中同源克隆到一个新的P450基因,命名为TaP450(Genbank No.KJ541960)。该基因基因组序列全长为2 643bp,含有2个外显子和1个内含子,cDNA全长为2 033bp,含有一个1 557bp的开放读码框,推导蛋白含518个氨基酸;序列分析发现其具有保守的P450结构域,但该蛋白与已报道的小麦P450蛋白序列有较大差异,表明它是小麦P450家族的新成员;蛋白结构特征分析发现,该蛋白的分子量为57.092kD,等电点为8.63,N端具有一个含29个氨基酸的跨膜结构和一个含22个氨基酸的信号肽,亚细胞定位分析表明该蛋白属于分泌蛋白。其在小麦叶片、茎、根与种子中均有表达,但在叶片和茎中表达量最高;在胁迫处理下,该基因的表达量均上调,且在盐胁迫处理下上调尤为显著,表明该基因与盐胁迫密切相关。     

燕麦AsRBP1基因克隆及表达特性分析

为了给AsRBP1基因在小麦抗逆转基因分子育种中的应用奠定理论基础,采用同源克隆方法从燕麦中克隆、获得AsRBP1基因,其cDNA序列全长447 bp,编码148个氨基酸.AsRBP1在氨基端具有典型的RNA识别基序(RNA-Recognition Motif,RRM),在羧基端富含甘氨酸,其含量达35.8％.系统进化树分析表明,AsRBP1与拟南芥AtGR-RBP7亲缘关系很近.实时荧光定量聚合酶链式反应(Real-time PolymeraseChain Reaction,RT-PCR)分析该基因的表达特性表明,AsRBP1明显受到外源脱落酸(Abscisic acid,ABA)与低温的诱导,同时对干旱和高盐胁迫也做出响应.由此,推测该基因属于GR-RBPs基因家族成员,可能参与逆境胁迫应答,在增强植物的抗逆性中发挥着重要的作用,可以为小麦抗逆分子育种提供优良候选抗逆基因资源.     

Natural enemies of the bagworm, Metisa plana Walker (Lepidoptera: Psychidae) and their impact on host population regulation

The bagworm, Metisa plana (Lepidoptera: Psychidae) is an important pest of oil palm, capable of being present as outbreak, which could cause a crop loss of up to 44%. Circumstantial evidence has long indicated that natural enemies play an important role in the population regulation of this pest. However, direct field data on the enemies themselves has been lacking.

A field study on a population of M. plana was made at PORIM Kluang, Johor, Malaysia from September 1988 to December 1992. The population of bagworm was initially high (late 1988, up to 38 larvae/frond, and in early 1990, up to 30 larvae/frond) but remained extremely low in the subsequent period (< 10 larvae/frond).

The population of M. plana was affected by both primary and secondary parasitoids and predators. Among the primary parasitoids, Dolichogenidea metesae was the most pronounced larval parasitoid of M. plana. This parasitoid was commonly attacked by hyperparasitoids, particularly Pediobius anomalus and Pediobius imbreus. A hypothetical life table constructed from the mortality figures of the declining part of the population during late 1988 confirmed that the natural enemies played a key role in suppressing the bagworm population.

The present study confirmed that overlapping generations were vital for the persistence of parasitoids of M. plana. The paper also suggested a possible need of alternative hosts. An active predator, Callimerus arcufer was also commonly encountered.     

Effects of plant diversity on the density and herbivory of the flea beetle, Phyllotreta cruciferae Goeze, in California collard (Brassica oleracea) cropping systems

Populations of the flea beetle, Phyllotreta cruciferae Goeze (Coleoptera:Chrysomelidae), were greater in weed-free collards than in collard monocultures and polycultures (intercropped with beans) left weedy for 2 or 4 weeks after transplanting or for the entire season. Flea beetle densities and amount of leaf damage per individual collard plant were significantly lower in the plots with crucifer weeds (mainly Brassica campestris L.), possibly because the beetles preferred to feed and/or concentrate on this plant rather than on collards.     

普通小麦TaTPR1基因的克隆及表达分析

具有TPR基序的蛋白质被认为能够介导蛋白质间的相互作用,并且参与多种生物学过程,如细胞周期调控、转录调控、过氧化物酶等蛋白质的运输、信号传导和蛋白质折叠等。为了在小麦分子育种研究中获得更多有价值的候选基因,本研究采用电子克隆和RT-PCR方法从小麦中克隆得到1个TPR类基因,命名为TaTPR1。该基因ORF长度972bp,推测编码包含323个氨基酸残基的蛋白,相对分子质量34.9kD,理论等电点为5.89。氨基酸序列分析表明,该蛋白在142~207区和207~274区分别含有TPR类基因家族特有的保守结构域(TPR_16和TPR_11)。进化和聚类分析表明,小麦TaTPR1基因与粗山羊草AtTPR15基因、乌拉尔图小麦TuTPR15基因的亲缘关系较近,蛋白相似度分别为91.28%和91.55%。Real-time PCR表达特性分析显示,该基因为组成型表达,在根、茎、叶中均表达;幼苗期茎中表达量较高,随幼苗的生长,茎中表达量上调显著;该基因表达受高盐的强烈诱导,也受水分、低温和外源ABA胁迫诱导。     

海南普通野生稻OrNAC5的克隆和表达分析

根据EST序列信息,从海南普通野生稻中克隆了一个NAC(NAM,ATAF and CUC)类转录因子OrNAC5。该基因编码区cDNA长度699 bp,编码232个氨基酸,对应的DNA长度为2 538 bp,含有3个外显子和2个内含子。推导的OrNAC5氨基酸序列具有典型的NAC类转录因子结构特征,与水稻(Oryza sativa)、短花药野生稻(Oryza brachyantha)、大麦(Hordeum vulgare)、谷子(Setaria italica)中相应蛋白的同源性分别为99%、81%、60%和58%。对OrNAC5启动子序列进行分析,结果发现存在多种激素应答和胁迫响应的调控元件。Real-Time PCR结果显示,低温、干旱和盐胁迫均能诱导OrNAC5的表达。上述结果表明OrNAC5可能在逆境响应过程中具有重要功能。     

香蕉3个Tau类谷胱甘肽硫转移酶基因的克隆及序列分析

了获得香蕉抗逆相关基因, 通过随机克隆测序和RACE（rapid-amplification of cDNA ends）的方法从香蕉根系cDNA文库中获得3个谷胱甘肽硫转移酶基因, 命名为MaGSTU1、 MaGSTU2和MaGSTU3（GenBank登录号分别为： KC261934、 KC261935和KC261936）。经5′RACE获得3个GST基因全长,分别包含1个627、 675 和699 bp的最大开放阅读框（Open Reading Frame, ORF）, 分别编码208、 224和232     

基因型和环境对以色列野生二棱大麦籽粒营养品质的影响

为探讨基因型和生长环境对野生二棱大麦营养性状的影响,对源自以色列不同地区的9个群体60个基因型野生二棱大麦材料在3个环境条件下的籽粒可溶性蛋白质、氨基酸、植酸、无机磷和淀粉含量及粒重进行测定,并对检测数据进行了单因素方差分析(One-Way ANOVA)、相关性网络分析(correlation-based network analysis,CNA)和斯皮尔曼秩相关分析(Spearmanp’s Rho Correlation)。结果表明,野生二棱大麦各被测性状与生长地土壤成分存在显著相关性(P0.01);以色列野生二棱大麦籽粒中无机磷、总淀粉含量和粒重受生长环境和基因型的共同影响,而植酸、可溶性蛋白质、氨基酸含量等性状则主要受生长地环境的影响。     

橡胶叶水浸提液对花生幼苗早期根系形态及其生理特性的影响

为深入理解橡胶树的化感抑制作用,采用适当浓度的橡胶叶水浸提液处理刚萌动的花生种子10 d,测定花生幼苗早期根系形态及其生理指标。结果表明:橡胶叶水浸提液能显著降低花生幼苗胚根长度、苗高、根鲜重、地上部鲜重以及根冠比,对根生长的抑制作用比地上部强烈;能显著降低根系总长、根表面积、根体积和根尖数,但对根平均直径有轻微的促进作用,与对照相比,差异不显著;能显著降低根系SOD、POD、CAT活性、可溶性蛋白质、可溶性糖、脯氨酸含量以及根系活力,却明显增加根系MDA含量和相对电导率。说明橡胶叶水浸提液可通过破坏花生幼苗的抗氧化防御机制,降低其渗透调节能力,减少根系的吸收面积,抑制根系的吸收活性来抑制花生幼苗的生长。     

Effect of host plant resistance and insecticide on brown planthopper Nilaparvata lugens (Stål) and predator population development in the Mekong Delta, Vietnam

Crop yield and populations of brown planthopper Nilaparvata lugens (Stål), whitebacked planthopper Sogatella furcifera (Horvath) (Homoptera: Delphacidae), green leafhopper Nephotettix spp. (Homoptera: Cicadellidae), and hemipteran and spider predators were monitored on rice varieties susceptible, moderately resistant, and highly resistant to N. lugens, under insecticide-treated and insecticide-free conditions. Nilaparvata lugens outbreaks and hopperburned plants were observed only in plots of the insecticide-treated susceptible varieties. In insecticide-free plots, the yield of the susceptible variety was lower than those of resistant varieties in only one of four seasons. In plots of a moderately resistant and a highly resistant variety, populations of N. lugens, S. furcifera, Nephotettix spp., and predators were generally similar, and yields did not differ, under both insecticide-treated and insecticide-free conditions. In insecticide-free plots, predator-N. lugens ratios were generally higher on resistant varieties than susceptible varieties. Two conclusions can'be drawn from our results relevant to the question of what levels of N. lugens host plant resistance are appropriate for farmers who do not overuse insecticides. First, susceptible varieties will not necessarily be damaged by N. lugens, even when N. lugens outbreaks occur in adjacent plots. Second, moderate and high levels of N. lugens resistance do not appear to be incompatible with biological control of N. lugens or other homopteran pests.     

黑皮冬瓜NBS类抗病基因同源序列克隆与分析

以黑皮冬瓜"B98K"种质为试材,根据已克隆的植物NBS类抗病基因保守结构域设计简并引物,PCR扩增冬瓜基因组DNA,获得对应区段的DNA片段,回收克隆与测序后,得到19条抗病同源序列(命名为DNB1至DNB19)。利用DNAStar软件进行序列分析及同源性比对发现,这些抗病同源序列长度在249~252 nt之间,其核苷酸序列同源性在48.4%~98.8%之间,氨基酸序列同源性为23.2%~100.0%,推导氨基酸序列具有P-loop(GGVGKTT)、Kinase-2a(VLDDVW)典型的NBS保守结构域。同源进化分析将其全部归为non TIR-NBS-LRR类,与推导氨基酸序列多重比较结果一致;该序列与其他作物已克隆抗病基因的氨基酸序列同源性在24.7%~99.0%之间。该组序列已登录Genbank,登录号为KF776401~KF776419。