温度胁迫对二化螟滞育幼虫生理指标的影响

为从生理生化水平上探讨二化螟滞育幼虫应对温度胁迫的生理机制,分别对系列温度胁迫(STS)和梯度温度胁迫(GTS)处理后的幼虫水、脂质、总糖、小分子碳水化合物含量及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性进行了测定.结果表明:随着温度的降低,两种处理二化螟滞育幼虫虫体含水量趋于减少,且0℃以下时GTS处理下降幅度较STS处理显著;两种处理脂质含量均逐步下降且二者间无显著差异;两种处理总糖含量分别先减后增和持续下降,均检测出4种小分子碳水化合物,其中STS处理葡萄糖、甘油和果糖含量先增后减,海藻糖含量变化与此相反,而GTS处理海藻糖含量先减后增,葡萄糖和甘油含量呈相反变化,果糖含量无变化;14～-14℃范围内STS处理SOD和POD活性较GTS处理低,CAT活性相反.二化螟滞育幼虫生理指标的变化反映了其应对不同温度胁迫的生理响应.     

Identification of tissues showing the lowest tolerance to freezing in larvae of the rice stem borer, Chilo suppressalis

Abstract.  Even though overwintering larvae of the rice stem borer, Chilo suppressalis , are freeze-tolerant, they cannot survive below −30 °C. Furthermore, nondiapausing larvae cannot survive freezing. However, the cause of death due to freezing is unclear. To identify the cause of death by freezing in larvae, those tissues most injured by low temperatures are identified using the vital stain trypan blue. In overwintering larvae, the midgut of dead larvae stains blue, and remarkable colour density differences between dead and surviving larvae are observed in the midgut. In nondiapausing larvae incubated at −10 °C for several hours, the fat body of dead larvae is strongly stained. Furthermore, increases in mortality with treatment time correspond with increases in the area of the fat body stained. Sterile nondiapausing larvae with lower supercooling points, below −20 °C, do not freeze at −10 °C and survive the treatment. However, all the larvae die when subjected to inoculative freezing at −10 °C, and the fat body stains blue. These results suggest that the midgut in overwintering larvae and the fat body in nondiapausing larvae have the lowest tolerance to freezing.     

How to analyze long-term insect population dynamics under climate change: 50-year data of three insect pests in paddy fields

We can precisely predict the future dynamics of populations only if we know the underlying mechanism of population dynamics. Long-term data are important for the elucidation of such mechanisms. In this article we analyze the 50-year dynamics of annual light-trap catches of three insect pest species living in paddy fields in Japan: the rice stem borer, Chilo suppressalis (Walker) (Lepidoptera: Pyralidae); the green rice leafhopper, Nephotettix cincticeps (Uhler) (Hemiptera: Deltocephalidae); and the small brown planthopper, Laodelphax striatellus (Fallén) (Hemiptera: Delphacidae). We separate the long-term dynamics into two components by using locally weighted scatterplot smoothing: (1) the underlying dynamics of populations, and (2) the influence of the past changes in the environment. The former component is analyzed by response surface analysis and vector autoregression to evaluate the nonlinearity of density-dependence and the inter-specific influence of density, respectively. On the basis of these analyses, we perform the state-space model analyses. The state-space model selected by Akaikes information criterion indicates that the observed number of light-trap catches of C. suppressalis and N. cincticeps in summer increases with increasing temperatures in the previous winter. It also indicates that the influence of temperature is not carried over to the next year. We utilize the selected model to predict the impact of global warming on these species, by substituting the temperature predicted by a general circulation model.     

再生稻二化螟幼虫空间分布型和抽样技术的研究

再生稻二化螟幼虫的空间布型为负二项分布和聚集分布,其lwao的线性回归方程为m^*=0.0099 2.4753m,属负二项分布。根据聚集均数（λ）测定结果,分析了聚集原因,在分布型研究的基础上,探讨了资料代换模式,Kuno‘s种群序贯抽样模型和最适抽样数模型。     

Gene cloning and expression of aminopeptidase N and cadherin from midgut of the rice stem borer,Chilo suppressalis

Abstract The rice stem borer, Chilo suppressalis Walker is one of the most important insect pests on rice in Asia, north Africa and southern Europe. Transgenic Bt rice has been developed in the laboratory with good resistance to this pest and other Lepidopteran insects, which will provide a possible alternative tool for this pest control. The full-length cDNAs encoding an aminopeptidase N (CsAPN) and a cadherin (CsCad) were cloned from C. suppressalis. CsAPN showed common features of, and high identities to, other insect APNs in its deduced amino acid sequence. Although a full-length cDNA encoding cadherin-like protein has been reported in GenBank, the newly isolated cadherin here (CsCad) showed some differences in its amino acid sequence, especially at the 7th cadherin repeat region (CR7), which indicated the newly isolated CsCad might be another allele. CsAPN and CsCad were successfully expressed in insect Tn cells, and the blot analysis showed these two proteins could bind Bt toxin Cry1Ab. The results will provide valuable information for the studies of toxin mode of action and the possible toxin resistance mechanisms in this pest.     

在实验室条件下水稻螟蛾发育和存活的温度需求(英文)

对6种水稻害虫Chilo polychrysa (Meyrick)、C. suppressalis (Walker), C. partellus (Swinhoe), Scirpophaga incertulas (Walker), S. innotata (Walker)和Sesamia inferens的卵、幼虫和蛹在10到40°C的七个固定温度下(10,15,20,25 30,35和40°C)的发育和存活进行了研究。在一定的温度下6种害虫的卵、幼虫和蛹的发育周期是明显不同的(P<0.0001)。卵、幼虫和蛹的日发育的平均百分比随着温度的增加而增加。总发育周期与温度的增加成反比。临界温度下限是在10-15°C中间,而上限在35-40°C中间,此时害虫并不发育。对于上述6种害虫的卵、幼虫和蛹的平均发育起点温度分别为8.57±1.71,7.70±1.01,8.56±3.25,10.19±2.19,8.64±2.68和7.91±0.82°C。6种水稻害虫的卵、幼虫和蛹的总温度常数分别是705.56,725.32,703.30,556.59,655.34和837.95日·度。经计算,6种雌蛾的产卵所需的积温分别为99.06,90.85,99.29,75.16,92.25和80.41日·度。完成一世代所需的积温分别是804.62,816.17,802.59,631.75,648.84 and 918.36日·度。     

水稻二化螟内共生菌杀雄菌属和沃尔巴克氏体的检测与分析

应用杀雄菌属(Arsenophonus)23S rDNA基因和沃尔巴克氏体(Wolbachia) wsp基因的特异引物,通过PCR扩增的方法对我国20个水稻二化螟地理种群感染两类内共生菌的情况进行了检测.结果表明: 我国水稻二化螟不同地理种群的Arsenophonus和Wolbachia感染率不一致,哈尔滨、惠水、吉林、南阳和扬州5个地理种群的Arsenophonus感染率为5.0%～50.0%;汉中、南宁和扬州3个地理种群的Wolbachia感染率为25.0%～40.0%,其他地理种群中没有检测到这两种共生菌的存在.水稻二化螟不同地理种群感染的Arsenophonus 23S rDNA基因序列完全一致,将该基因株型命名为csArs.但所检测到的Wolbachia wsp基因序列不一致,分别为wChisup1、wChisup5和wChisup6,其中wChisup1属于A群,其他属于B群.这说明水稻二化螟感染的Arsenophonus为同一株型,而感染的Wolbachia株型较为复杂.通过构建系统发育树发现,水稻二化螟体内的Arsenophonus23S rDNA基因和Wolbachia wsp基因与其他物种体内相关序列完全一致或高度相似.     

Population genetic structure of Chilo suppressalis (Walker) (Lepidoptera: Crambidae): strong subdivision in China inferred from microsatellite markers and mtDNA gene sequences

Chilo suppressalis (Walker) displays significant geographical differences in ecological preference that may be congruent with patterns of molecular variation. To test this, we collected and analysed 381 individuals of this species from cultivated rice at 18 localities in China during the rice-growing season of 2005–2006. We used four microsatellite DNA markers and four mitochondrial DNA gene fragments. We found that this species is highly differentiated, coupled with an estimated population expansion date of at least 60 000  bp . Phylogenetic analyses, Bayesian clustering, and phylogeographical analyses of statistical parsimony haplotype network consistently divided the populations into three clades: a central China (CC) clade, a northern plus northeastern China (NN) clade and a southwestern China (SW) clade. Analysis of molecular variance indicated a high level of geographical differentiation at different hierarchical levels [ F _ST for microsatellite markers, COI, COII, 16S and ND1 is 0.06004 ( P  < 0.0001), 0.27607 ( P  < 0.0001), 0.22949 ( P  < 0.0001), 0.19485 ( P  < 0.0001) and 0.29285 ( P  < 0.0001), respectively]. Isolation by distance appeared among the samples from within China ( r  = 0.404, P  = 0.0002); N_em values estimated using a coalescent-based method were small (< 2 migrants per generation), suggesting that the observed levels of differentiation are a result of migration–drift equilibrium. Our results imply that the genetic differentiation of this borer, which is approximately in accordance with its observed number of generations per year in different Chinese geographical regions, is probably attributed to climatic and/or geological events (e.g. the last glacial maximum) and subsequently strengthened by the domestication of rice.     

水稻二化螟灾变规律与栽培因素之关系分析

通过对20多年的历史资料分析,近年来安徽省广德县水稻二化螟Chilo suppressalisWalker灾变规律发生了新变化:发生期推迟,发生程度加重,主害世代推后。栽培因素如种植制度的调整,优质稻品种的普及,水稻播、栽期的推迟,免耕技术的推广等与其关系密切。这些因素将继续向有利于害虫方向发展,螟虫重发仍将持续。对螟虫的预测与控制必须予以关注。