不同地区转Bt基因抗虫水稻稻谷对赤拟谷盗生长发育的影响

为了明确来自湖北武穴、孝感、随州3个不同地区的转cry1Ab/cry1Ac、cry2A、cry1C基因明恢63(分别命名为TT51、T2A-1和T1C-19)对赤拟谷盗Tribolium castaneumHerbst生长发育的影响,在室内以不同的转Bt基因稻谷继代饲养赤拟谷盗6代,结果表明:各处理赤拟谷盗的卵期3～4d,卵孵化率85%～100%,幼虫期22～27d,化蛹率85%～97%,蛹期6～7d,百蛹重0.25～0.31g,性比0.8～1.4,羽化率82%～97%,产卵前期5～7d。不同抗虫转基因水稻对赤拟谷盗各发育历期及生命表参数没有显著的影响,同一转基因事件,没有因为种植地区的不同造成对赤拟谷盗生长发育的差异。3种Bt蛋白在继代饲养的赤拟谷盗幼虫体内检测均呈阳性反应,但积累量很小,继代饲养后,没有发现在赤拟谷盗体内明显的累积。     

温湿度对赤拟谷盗成虫飞行能力的影响

本文利用昆虫飞行磨研究了温度和湿度变化对赤拟谷盗Tribolium castaneum(Herbst)雌、雄成虫飞行能力的影响;分别测定了23℃、26℃、29℃、32℃和35℃等5个温度,45%、65%和85%等3个湿度条件下,赤拟谷盗雌、雄成虫的飞行距离、时间和速度等反应昆虫飞行能力的参数。单次飞行距离、单次飞行时间、单次飞行速度、24 h累计飞行距离及时间分析结果表明,环境温度和湿度对赤拟谷盗雌、雄成虫的飞行能力有不同程度的影响,环境温湿度过高或过低均不利于赤拟谷盗雌、雄成虫飞行;温度为32℃时,赤拟谷盗雌成虫的单次飞行距离、飞行时间、飞行速度、24 h累计飞行距离和飞行时间分别为0.925 m、9.616 s、0.023 m/s、0.979 km和2.886 h;雄成虫的单次飞行距离、飞行时间、飞行速度、24 h累计飞行距离和飞行时间分别为0.638 m、6.035 s、0.014 m/s、0.674 km和3.175 h。在相对湿度45%、65%和85%时,雌成虫的单次飞行时间分别为6.998 s、9.616 s和6.431 s;雄成虫的单次飞行时间分别为3.163 s、6.035 s和0.208 s。飞行速度与相对湿度的关系与飞行时间相似。从飞行能力参数来看,雌虫的飞行能力优于雄虫。     

敲减Wingless / Wnt1基因表达对赤拟谷盗发育中的影响

Wnt信号通路是进化中高度保守的一条信号转导途径,在调控动物的胚胎轴向正常发育、胚胎分化、决定细胞极性、维持成体动态平衡等方面发挥重要作用. 该信号通路的异常激活还与肿瘤的发生密切相关. 本实验将体外人工合成的Wingless(Wg)/Wnt1基因dsRNA显微注射入赤拟谷盗晚期幼虫体内,研究Wingless/Wnt1蛋白在赤拟谷盗发育过程中发挥的作用. 实验结果显示,注射 Wingless(wg)/Wnt1基因dsRNA后,赤拟谷盗发育形成的蛹,翅膀宽度减小,翅间距明显增大,且羽化过程也受到严重影响. 此外,qPCR结果表明,赤拟谷盗Wingless(Wg)/Wnt1基因被沉默后,Cadherin-like 和 Smoothened (Smo)基因的表达显著上调,Armadillo-2基因略上调. 这些结果揭示,Wnt-1 信号通路和赤拟谷盗翅膀发育以及成虫羽化过程密切相关. 蛹翅宽减小,翅间距增大,可能是由于调控细胞粘连及细胞形态的Cadherin-like 和Armadillo-2基因的上调所引起.更重要的是,Smo基因的上调,表明了Wnt信号通路和Hedgehog信号通路在赤拟谷盗发育过程中有交互作用.     

十二种药用植物乙醇提取物对谷蠹和赤拟谷盗成虫的驱避效应

采用滤纸药膜选择法研究了蛇床子、茵陈、萹蓄等12种药用植物乙醇提取物对谷蠹Rhizopertha dominica(Fab.)和赤拟谷盗Tribolium castaneum Herbst成虫的驱避效应。12种药用植物以蛇床子(Cnidium monnieri)提取物对谷蠹成虫的驱避效果最佳,786μg/cm2处理24h对谷蠹的驱避率达93%;茵陈(Artemisia capillaries)提取物对赤拟谷盗成虫的驱避效果最佳,用393μg/cm2处理72h的驱避率为95%,茵陈提取物以262μg/cm2放置7d后对赤拟谷盗成虫的驱避率可达Ⅴ级水平。茵陈提取物对赤拟谷盗的驱避持效期长、效果好,具有一定的开发前景。     

赤拟谷盗和杂拟谷盗的生殖隔离研究

赤拟谷盗和杂拟谷盗是两个同域发生的近缘储粮害虫。为明确它们的生殖隔离程度和机制,本研究比较分析了赤拟谷盗和杂拟谷盗雄虫对同种和异种雌虫的交配选择;赤拟谷盗与杂拟谷盗交配后,测定了精子在异种雌体内的存活情况;将赤拟谷盗和杂拟谷盗进行正反杂交,研究其F1代、F2代和回交代杂种是否产生及其雌雄比。结果显示,赤拟谷盗和杂拟谷盗雄虫对同种雌虫的爬跨率和交配率高于其对异种雌虫的爬跨率和交配率,表明赤拟谷盗和杂拟谷盗种间性隔离不完全;赤拟谷盗和杂拟谷盗交配后精子在异种雌体内是存活的,杂交所产的F1代卵为受精卵,说明交配后完成了精子传送和受精过程,表明种间机械隔离和配子隔离不完全;赤拟谷盗和杂拟谷盗的杂种F1代自交和回交产生了F2代和回交代,表明种间不存在杂种不育;一些杂交组合产生的F2代和回交代数量少且存在雌雄性比偏离,表明种间存在部分杂种不活和杂种衰败。本研究明确了赤拟谷盗和杂拟谷盗的生殖隔离机制,这对于揭示它们的物种进化关系有着重要意义。     

锈赤扁谷盗成虫趋光行为研究

【目的】研究灯光诱捕技术防治锈赤扁谷盗Cryptolestes ferrugineus(Stephens)的可行性。【方法】在实验室条件下测定了锈赤扁谷盗成虫对不同光源的趋光反应。【结果】锈赤扁谷盗成虫对实验所选取的光源都有一定的趋性。在可见光中,对主波长为575 nm的光源的趋性最强,对430、495、620、530和450 nm光源的趋性依次降低。在紫外光中,对主波长为385 nm的光源的趋性显著高于对主波长为365、375和395 nm的光源;1~10日龄的锈赤扁谷盗成虫,随日龄的增加,成虫趋光性先增强后有所减弱;雌虫的趋光性高于雄虫,且交配状态会影响雌虫和雄虫的趋光性。交配会抑制雄虫的趋光性,但是交配后的雌虫的趋光性增强;短期饥饿处理和灯光经历对害虫趋光性无显著影响。【结论】锈赤扁谷盗成虫对光波长的选择偏好性证实了其灯光诱捕技术的可行性。     

种间竞争对四种储粮害虫种群动态的影响

在30 ℃、75 %相对湿度条件下研究种间竞争对玉米象(Sitophilus zeamais)、谷蠹(Rhizopertha domini-ca)、赤拟谷盗(Triboliumcastaneum)和锈赤扁谷盗(Cryptolestes ferrugineus)4种主要储粮害虫种群动态的影响,并对种群动态进行回归分析。结果表明,玉米象与谷蠹、赤拟谷盗与锈赤扁谷盗混合饲养种群增长均受到显著抑制,玉米象和谷蠹对赤拟谷盗和锈赤扁谷盗的种群增长具有明显的促进作用,赤拟谷盗和锈赤扁谷盗对玉米象和谷蠹的种群增长具有一定的抑制作用。回归分析结果表明玉米象种群最大增长潜能最大,锈赤扁谷盗最小,种群增长率变化规律不明显。     

球孢白僵菌九个菌株对赤拟谷盗成虫的毒效

球孢白僵菌Beauveria bassiana (Balsamo) Vuillemin是最重要的昆虫病原真菌,广泛用于防治世界各地的多种害虫.本研究评价了球孢白僵菌9个菌株对赤拟谷盗Tribolium castaneum (Herbst)成虫的致病性.将15头赤拟谷盗成虫浸入到4个浓度(1×106,l×107,l×lo8和l×109个分生孢子/mL)的白僵菌菌株中20 s,14 d内每日记录成虫的死亡率.结果表明:IRAN 440C菌株对赤拟谷盗成虫的LC50最低(5.04 ×l07个分生孢子/mL),IRAN187C菌株的最高(5.05 ×lo8个分生孢子/mL);DEBI 005菌株对赤拟谷盗成虫的LT5o最短(2.88 d),DEBI 014菌株的最长(4.96 d).根据LC50,LT50和死亡率结果得出IRAN 440C是防治这一害虫的理想菌株.     

不同地理种群赤拟谷盗肠道细菌群落多样性分析

【目的】了解储粮害虫赤拟谷盗Tribolium castaneum (Herbst)成虫肠道细菌群落组成及多样性。【方法】利用Illumina MiSeq高通量测序技术对3个地理种群的赤拟谷盗雄虫肠道细菌16S rDNA的V3-V4变异区进行测序分析。【结果】从赤拟谷盗肠道样本中共测得465 293条reads,聚类为113个OTU,共注释到8门、15纲、33目、52科和79属的细菌。其中,优势菌门包括变形菌门(Proteobacteria)、厚壁菌门(Firmicutes)和放线菌门(Actinobacteria)等,优势菌属包括假单胞菌属(Pseudomonas)、肠杆菌科未鉴定属(Unclassified-f-Enterobacteriaceae)、不动杆菌属(Acinetobacter)、肠球菌属(Enterococcus)和根瘤菌属(Rhizobium)等。3个地理种群的赤拟谷盗肠道细菌的Shannon指数、Simpson指数、Ace指数和Chao指数分别为1.5-1.7、0.3、79.7-133.2和76.4-85.2。【结论】不同地理种群的赤拟谷盗成虫的肠道细菌群落组成存在显著差异。     

定虫隆对锈赤扁谷盗生长发育影响及其作用机理初探

定虫隆是一种昆虫生长调节抑制剂,研究其对锈赤扁谷盗的控制作用,将为锈赤扁谷盗的综合防治提供理论基础。本研究以锈赤扁谷盗幼虫为研究对象,用定虫隆拌粮进行饲喂,观察定虫隆对锈赤扁谷盗的亚致死效应,并利用实时荧光定量PCR(qPCR)技术,测定经定虫隆处理后锈赤扁谷盗幼虫几丁质合成酶1(CfCHS1)和几丁质合成酶2(CfCHS2)基因表达量的变化。结果表明:定虫隆对锈赤扁谷盗的毒力回归方程为y=7.514+1.81x(r=0.974),LD 10、LD 20、LD 30分别为0.008 mg/kg、0.014 mg/kg、0.021 mg/kg,亚致死剂量定虫隆可使锈赤扁谷盗幼虫发育历期明显延长(P<0.05),体重和几丁质含量明显降低(P<0.05),这说明了定虫隆对锈赤扁谷盗的生长发育有明显的抑制作用,可以有效控制锈赤扁谷盗的为害。qPCR结果显示,与对照组相比,LD 30处理后的锈赤扁谷盗幼虫的CfCHS 1基因表达量提高了74.7%,CfCHS 2基因的表达量提高了27.4%,均差异显著(P<0.05)。CfCHS 1和CfCHS2基因表达量的上调,可能是几丁质合成酶受到了抑制,锈赤扁谷盗为了维持机体的稳定,提高几丁质合成酶基因的表达量,从而形成一种代偿性增加的反馈机制,由此推测定虫隆可能作用于几丁质合成酶。     

Influence of nutrition on male development and reproduction in Tribolium castaneum

Tribolium beetles have evolved over several thousand years to colonize and exploit various food products that vary widely in their nutritional quality. Here Tribolium castaneum was used as a model organism to explore the effect of nutritional quality on male development and reproduction. The results showed, when tested across different qualities of nutritional diets, Tribolium males developed faster and their body size was larger on a high-quality diet, and there were significant correlations between male developmental traits. However, Tribolium males fed different nutritional diets did not show significant variation in olfactory attractiveness, mating rate, insemination rate, sperm defense (P1), sperm offense (P2), and reproductive success within a population context (RSPC). Moreover, there was no significant correlation of male reproductive performances except RSPC with developmental traits, and except for P2 and RSPC, no significant correlations between male reproductive performances. Therefore, although male developmental performance was significantly influenced by diet quality, reproductive performance was not. We discussed these findings and their sexual selection implications in light of its habitat.     

Condition‐dependent expression of pre‐ and postcopulatory sexual traits in guppies

Female choice can impose persistent directional selection on male sexually selected traits, yet such traits often exhibit high levels of phenotypic variation. One explanation for this paradox is that if sexually selected traits are costly, only the fittest males are able to acquire and allocate the resources required for their expression. Furthermore, because male condition is dependent on resource allocation, condition dependence in sexual traits is expected to underlie trade‐offs between reproduction and other life‐history functions. In this study we test these ideas by experimentally manipulating diet quality (carotenoid levels) and quantity in the guppy (Poecilia reticulata), a livebearing freshwater fish that is an important model for understanding relationships between pre‐ and post‐copulatory sexually selected traits. Specifically, we test for condition dependence in the expression of pre‐ and postcopulatory sexual traits (behavior, ornamentation, sperm traits) and determine whether diet manipulation mediates relationships among these traits. Consistent with prior work we found a significant effect of diet quantity on the expression of both pre‐ and postcopulatory male traits; diet‐restricted males performed fewer sexual behaviors and exhibited significant reductions in color ornamentation, sperm quality, sperm number, and sperm length than those fed ad libitum. However, contrary to our expectations, we found no significant effect of carotenoid manipulation on the expression of any of these traits, and no evidence for a trade‐off in resource allocation between pre‐ and postcopulatory episodes of sexual selection. Our results further underscore the sensitivity of behavioral, ornamental, and ejaculate traits to dietary stress, and highlight the important role of condition dependence in maintaining the high variability in male sexual traits.     

Genetic and nutritional effects on male traits and reproductive performance in Tribolium flour beetles

In Tribolium flour beetles and other organisms, individuals migrate between heterogeneous environments where they often encounter markedly different nutritional conditions. Under these circumstances, theory suggests that genotype-by-environment interactions (GEI) may be important in facilitating adaptation to new environments and maintaining genetic variation for male traits subject to directional selection. Here, we used a nested half-sib breeding design with Tribolium castaneum to partition the separate and joint effects of male genotype and nutritional environment on phenotypic variation in a comprehensive suite of life-history traits, reproductive performance measures across three sequential sexual selection episodes, and fitness. When male genotypes were tested across three nutritional environments, considerable phenotypic plasticity was found for male mating and insemination success, longevity and traits related to larval development. Our results also revealed significant additive genetic variation for male mating rate, sperm offence ability (P(2)), longevity and total fitness and for several traits reflecting both larval and adult resource use. In addition, we found evidence supporting GEI for sperm defence ability (P(1)), adult longevity and larval development; thus, no single male genotype outperforms others in every nutritional environment. These results provide insight into the potential roles of phenotypic plasticity and GEI in facilitating Tribolium adaptation to new environments in ecological and evolutionary time.     

The influence of the nutritional content of the adult male diet on testis mass, body condition and courtship vigour in a Hawaiian Drosophila

1. The effects of the nutritional quality of the adult diet (primarily protein content) on testis mass, body condition and courtship vigour were studied in a Hawaiian Drosophila, D. grimshawi , a lek-forming species under strong sexual selection. The primary goals of this study were to determine whether there is a trade-off between investment in reproductive and somatic tissues, and to examine whether this trade-off is influenced by quality of the adult diet.
2. Quality of the adult diet had a major influence on male body condition, courtship vigour and testis mass, but males varied in their investment patterns even within diet treatment.
3. Body condition, a measure of phenotypic quality, was significantly related to how much males invested in testis and body tissues, but the nature of the relationships differed between males fed high- or low-quality diets.
4. Paragonia volume was significantly smaller for adult males fed low-quality diets than for males fed high-quality diets. Nutrient-deficient diets apparently forced males to trade off investment in testes and body condition, and in body condition and courtship vigour, but nutrient-rich diets did not result in severe trade-offs.
5. Collectively, the results suggest that fluctuation in adult diet quality of male D. grimshawi might influence male reproductive quality in ways that might limit female reproductive output and/or be a factor for female choice in this species.     

Diet alters male horn allometry in the beetle Onthophagus acuminatus (Coleoptera: Scarabaeidae)

Darwin considered the horns of male beetles to be among the most striking examples of sexual selection. As with antlers in deer or elk, beetle horns scale positively with male body size, with the result that large males have disproportionately longer horns than small males. It is generally assumed that such scaling relationships (''static allometries'') are insensitive to short-term changes in the environment, and for this reason they are regularly used as diagnostic attributes of populations or species. Here I report breeding experiments on horned beetles that demonstrate that the scaling relationship between male horn length and body size changes when larval nutrition changes. Males reared on a low-quality diet had longer horn lengths at any given body size than sibling males reared on a high-quality diet. Such ''allometry plasticity'' may explain seasonal changes observed in this same scaling relationship in a natural population. These experiments demonstrate that scaling relationships of sexually selected traits can respond facultatively to variation in the environment, thereby revealing a new mechanism by which males regulate the production of exaggerated secondary sexual traits.     

Sexual shape dimorphism accelerated by male–male competition,but not prevented by sex-indiscriminate parental care in dung beetles (Scarabaeidae)

Dimorphic sexual differences in shape and body size are called sexual dimorphism and sexual size dimorphism, respectively. The degrees of both dimorphisms are considered to increase with sexual selection, represented by male–male competition. However, the degrees of the two dimorphisms often differ within a species. In some dung beetles, typical sexual shape dimorphisms are seen in male horns and other exaggerated traits, although sexual size dimorphism looks rare. We hypothesized that the evolution of this sexual shape dimorphism without sexual size dimorphism is caused by male–male competition and their crucial and sex-indiscriminate provisioning behaviors, in which parents provide the equivalent size of brood ball with each of both sons and daughters indiscriminately. As a result of individual-based model simulations, we show that parents evolve to provide each of sons and daughters with the optimal amount of resource for a son when parents do not distinguish the sex of offspring and males compete for mates. This result explains why crucial and sex-indiscriminate parental provisioning does not prevent the evolution of sexual shape dimorphism. The model result was supported by empirical data of Scarabaeidae beetles. In some dung beetles, sexual size dimorphism is absent, compared with significant sexual size dimorphism in other horned beetles, although both groups exhibit similar degrees of sexual shape dimorphism in male horns and other exaggerated traits.     

Plasticity of size and allometry in multiple sexually selected traits in an armed beetle <Emphasis Type="Italic">Gnatocerus cornutus</Emphasis>

Male-male competition frequently results in the evolution of sexually selected traits used as weapons and ornaments. The expression of these traits often depends on male condition, i.e., condition dependence. Although males often have multiple sexually selected traits, to date many studies have focused on the morphological analysis of one sexual trait whilst ignoring the others. We here report phenotypic plasticity for multiple sexual traits, by manipulating larval diet quality and density, in the broad-horned flour beetle Gnatocerus cornutus. The male beetles possess enlarged mandibles, developed genae and a pair of small horns, but females lack these completely. Larval density significantly affected overall body size but not relative investment in each sexual trait. In contrast, diet quality had no effect on body size but had a significant effect on relative investment in the mandibles and genae. These results indicate that the allometric intercepts of the mandible and genae alter in response to diet quality, i.e., allometric plasticity. However, diet quality had no effect on the growth of the horn. Thus, multiple sexual traits exhibited differences in plasticity as a result of larval nutrient condition in G. cornutus males.     

Resource quality affects weapon and testis size and the ability of these traits to respond to selection in the leaf‐footed cactus bug,Narnia femorata

The size of weapons and testes can be central to male reproductive success. Yet, the expression of these traits is often extremely variable. Studies are needed that take a more complete organism perspective, investigating the sources of variation in both traits simultaneously and using developmental conditions that mimic those in nature. In this study, we investigated the components of variation in weapon and testis sizes using the leaf‐footed cactus bug, Narnia femorata (Hemiptera: Coreidae) on three natural developmental diets. We show that the developmental diet has profound effects on both weapon and testis expression and scaling. Intriguingly, males in the medium‐quality diet express large weapons but have relatively tiny testes, suggesting complex allocation decisions. We also find that heritability, evolvability, and additive genetic variation are highest in the high‐quality diet for testis and body mass. This result suggests that these traits may have an enhanced ability to respond to selection during a small window of time each year when this diet is available. Taken together, these results illustrate that normal, seasonal fluctuations in the nutritional environment may play a large role in the expression of sexually selected traits and the ability of these traits to respond to selection.     

Starvation resistance is positively correlated with body lipid proportion in five wild caught Drosophila simulans populations

Stress resistance traits in Drosophila often show clinal variation, suggesting that selection affects resistance traits either directly or indirectly. One of the most common causes of stress for animals is the shortage or suboptimal quality of food, and individuals within many species must survive periods of starvation or exposure to nutritionally imbalanced diets. This study determines the relationship between starvation resistance, body lipid content, and lifespan in five recently collected Drosophila simulans populations from four distinct geographic localities. Despite rearing under standard nutritional conditions, we observed significant differences in starvation resistance between sexes and between localities. If body lipid proportion is included as a covariate in statistical analysis the difference between the sexes remains (slopes are parallel, with males more susceptible than females to starvation across all lipid proportions) but the effect of locality disappears. This result suggests that flies from different localities differ in their susceptibility to starvation because of differences in their propensity to store body lipid. We observed a negative relationship between lifespan and starvation resistance in both males and females, suggesting a fitness cost to increasing lipid reserves. These data raise issues about the role of diet in maintaining life history trait variation within and among populations. In conclusion, we show many similarities and surprising differences in life history traits between D. simulans and Drosophila melanogaster.     

Fitness components of Drosophila melanogaster developed on a standard laboratory diet or a typical natural food source

Drosophila melanogaster is often used as a model organism in evolutionary biology and ecophysiology to study evolutionary processes and their physiological mechanisms. Diets used to feed Drosophila cultures differ between laboratories and are often nutritious and distinct from food sources in the natural habitat. Here we rear D. melanogaster on a standard diet used in our laboratory and a field diet composed of decomposing apples collected in the field. Flies developed on these two diet compositions are tested for heat, cold, desiccation, and starvation resistance as well as developmental time, dry body mass and fat percentage. The nutritional compositions of the standard and field diets were analyzed, and discussed in relation to the phenotypic observations. Results showed marked differences in phenotype of flies from the two types of diets. Flies reared on the field diet are more starvation resistant and they are smaller, leaner, and have lower heat resistance compared to flies reared on the standard diet. Sex specific effects of diet type are observed for several of the investigated traits and the strong sexual dimorphism usually observed in desiccation resistance in D. melanogaster disappeared when rearing the flies on the field diet. Based on our results we conclude that care should be taken in extrapolating results from one type of diet to another and especially from laboratory to field diets.