Response of successive three generations of cotton,bollworm,Helicoverpa armigera (Hübner),fed on cotton bolls under elevated CO_2

The growth, development and consumption of successive three generations of cotton bollworm, Helicoverpa armigera （Htibner）, fed on cotton bolls grown under elevated CO2 （double-ambient vs. ambient） in open-top chambers were examined. Significant decreases in protein, total amino acid, water and nitrogen content and increases in free fatty acid were observed in cotton bolls. Changes in quality of cotton bolls affected the growth, development and food utilization of H. armigera. Significantly longer larval development duration in three successive generations and lower pupal weight of the second and third generations were observed in cotton bollworm fed on cotton bolls grown under elevated CO2. Significantly lower fecundity was also found in successive three generations of H. armigera fed on cotton bolls grown under elevated CO2. The consumption per larva occurred significant increase in successive three generations and frass per larva were also significantly increased during the second and third generations under elevated CO2. Significantly lower relative growth rate, efficiency of conversion of ingested food and significant higher relative consumption rate in successive three generations were observed in cotton bollworm fed on cotton bolls grown under elevated CO2. Significantly lower potential female fecundity, larval numbers and population consumption were found in the second and third generations of cotton bollworm fed on cotton bolls grown under elevated CO2. The integrative effect of higher larval mortality rate and lower adult fecundity resulted in significant decreases in potential population consumption in the latter two generations. The results show that elevated CO2 adversely affects cotton bolls quality, which indicates the potential population dynamics and potential population consumption of cotton bollworm will alleviate the harm to the plants in the future rising CO2 atmosphere.

Response dynamics of three defense related enzymes in cotton leaves to the interactive stress of Helicoverpa armigera (Hübner) herbivory and omethoate application

In order to explore the response dynamics of the activities of defense related enzymes in cotton leaves towards the interactive stress of Helicoverpa armigera herbivory and omethoate application, the activities of phenylalanine ammonia-lyase（PAL）, lipoxygenase（LOX）, and polyphenol oxidase（PPO） were examined from 6 to 126 h after cotton leaves were treated 12 h of H. armigera herbivory, and then sprayed with 800 mg L–1 omethoate. The results showed that the changes in the activities of PAL, LOX and PPO that occured under the interactive stress of H. armigera herbivory and omethoate application reflected the interactive effects of the two stresses on cotton defense. The similarity between the response dynamics of PAL, LOX, and PPO activities in cotton leaves under the interactive stress and that under H. armigera herbivory treatment alone showed that the induction of H. armigera herbivory on the activities of PAL, LOX and PPO in cotton leaves played a leading role in the interactive effects, and the effect of omethoate application played only a minor role. A joint factor analysis was performed according to a method which has been used to analyze the joint toxicity of pesticides; this analysis sought to clarify if there was a synergistic, antagonistic, or additive effect on PAL, LOX, and PPO activity in cotton leaves resulting from the interactive H. armigera herbivory and omethoate treatment. In the interactive effect on the response of PAL activity in cotton leaves, antagonistic effects of the omethoate application towards H. armigera herbivory were observed at 6 and 12 h. Synergistic effects were then observed at 18 and 30 h. Antagonistic effects were observed from 54 to 78 h and synergistic effects were finally observed at 126 h. The correlation between H. armigera herbivory and omethoate application in the interactive effect on cotton defense responses of LOX activity also fluctuated from synergism to antagonism during the time course. In the interactive effect on PPO activity, only antagonism was observed between H. armigera herbivory and omethoate application. In the interactive stress of H. armigera herbivory and omethoate application on cotton defense responses, omethoate affected the defense responses of cotton to H. armigera herbivory by producing antagonistic and synergistic effects. These results will be useful to understand the relationship between host plant and herbivorous pest.

Performances of the cotton bollworm,Heliothis armigera (Hubner) at different temperatures and relative humidities

The cotton bollworm, Heliothis armigera (Hubner) is an important insect species at-tacking many crops. Their performances have been examined at temperatures from 15℃ to 35℃ and relative humidities (RH) between 22.5% and 100%, respectively, in order to assess possible effect of climate in future on its occurrence and infestation. Durations of all developmental stages of the insect shortened with increasing temperature. The temperature favoring population growth ranged from 25℃ to 30℃.Larval duration and adult longevity decreased as relative humidity increased, but development of other stages was independent of RH. At RH of over 64%, their survival rate, egg production and oviposition rate varied a little, and all the population parameters of the insect remained at a relative constant level.

Pyramiding Breeding by Marker-Assisted Recurrent Selection in Upland Cotton: Selected Effects on Resistance to Helicoverpa armigera

The coincidence rates were more than 96% among the instar-weighted average of bioassaysin the lab, the percentage of resistance to Km in the field and the percentage of plantscontaining Bt gene. So, the performance of resistance to Km in the field can be used torepresent the transgenic Bt gene for selecting the resistance to bollworm. The instar-weighted averages were 30.585, 24.182, 16.615, 10.601, 10.123, 7.440 and 7.215 for theC0, P1, M1, M2, MP1, P2 and MP2 populations, respectively. The variance analysisindicated that the instar-weighted average in C0 was greatly significantly higher thanthat in all other populations, i.e., the performance of resistance to bollworm in C0 washighly significantly lower than all other populations. And the resistance in P1 wasgreatly lower than that of M1, M2, MP1, P2 and MP2, and M1 greatly lower than that of M2,MP1, P2 and MP2. There were no significant differences among M2, MP1, P2 and MP2. Withinthe populations of the first cycle selection, MP1 and M1 were greatly significantlyhigher than P1, and MP1 significantly higher than M1. The populations of the second cycleselection were significantly higher than their initial population M1, but no significantdifference among them. The boll size, seed index, the percent of the first harvest yield,fiber length, strength and elongation of the resistant plants to bollworm were significantlylower than that of sensitive plants to bollworm. And the yield of seed and lint cottonof the resistant plant to bollworm were lower than that of the sensitive to bollworm, butno significant difference between them. The boll numbers per plant, lint percent andmicronaire of the resistant plants to bollworm were significantly higher than that of thesensitive plant to bollworm.

Transcriptome and metabolome analysis reveal that oral secretions from Helicoverpa armigera and Spodoptera litura influence wound-induced host response in cotton

Cotton(Gossypium hirsutum)is an important fiber crop worldwide.Insect attack causes cotton yield and quality losses.However,little is known about the mechanism of cotton response to insect attack.We simulated insect feeding by applying insect oral secretions(OS)to wounds,and combined transcriptome and metabolome analysis to investigate how OS from two major pest species(Helicoverpa armigera and Spodoptera litura)affect cotton defense responses.We found that respectively 12,668 and 13,379 genes were differentially expressed in comparison with wounding alone.On addition of OS,the jasmonic acid signaling pathway was rapidly and strongly induced,whereas genes involved in salicylic acid biosynthesis were downregulated.On constructing a coexpression gene network,we identified a hub gene encoding a leucine-rich repeat receptor kinase that may play an important role in early signal recognition and transduction.OS from the two insect species altered the abundance of flavonoid-related compounds in different patterns.Gossypol remained in lower concentration after OS application than after wounding alone,suggesting a suppressive effect of OS on cotton defense response.This study illustrated transcriptional and metabolic changes of cotton in responding to OS from two chewing insect species,identified potential key response genes,and revealed evidence for OS inhibition of wounding-induced cotton defense response.

Effects of NaCl stress on the biochemical substances in Bt cotton as well as on the growth and development and adult oviposition selectivity of Helicoverpa armigera

Background:Recently,due to the development of food security strategies,cotton has been planted in inland saline-alkali dry soils or in coastal some saline-alkali soils in China.Under the condition,to comprehensively prevent and control Helicoverpa armigera in cotton fields with saline-alkali soils,it is important to study the larval growth and development of H.armigero and to study adult oviposition selectivity in H.armigera adults that feed on NaCI-stNaCled cotton plants.Results:In this study,Bt cotton GK19 was used for the experimental group and its nontransgenic parent Simian 3 was used for the control to study the effects of biochemical substances in cotton as well as larval growth and development and adult oviposition selectivity of H.armigera.The experiments were performed by growing cotton indoors under NaCl stress at concentrations of 0 mmol-L-1,75 mmol-L-1 and 150 mmol-L-1,respectively.The results showed that the expression of Bt protein was significantly inhibited for NaCI-stressed Bt cotNaClThe content of soluble protein and K+ in the leaves of cotton were decreased,while the content of gossypol and Na+were increased.In addition,the 5th instar H.armigera larvae exhibited shorten the life span in a 13-day trial period.Under enclosure treatments and at different female densities,the adult oviposition of H.armigera decreased on high NaCI-stressed nontransgenic coNaCl,while the oviposition on Bt cotton tended to first increase but then decrease under low,moderate and high NaCl stress treatments.Conclusions:Under certain content ranges of NaCl stress treatments,larval of H.armigera growth and development,and adult oviposition were no significant difference in the change for a certain period.However,under high NaCl stress,larval growth,development and adult oviposition were affected,which may provide insights for the prevention and control of H.armigero for Bt cotton in saline-alkali soils.

棉铃虫(Helicoverpa armigera)幼虫性特征和精子的发生

以棉铃虫精巢为材料,气干法制片,Giemsa染色,研究了棉铃虫精巢的形态变化和精子发生的动态过程。结果表明:棉铃虫的精巢自预蛹期开始会发生融合现象;雄性棉铃虫染色体数目为n=31。还发现雌性幼虫的腹部有4个腺体,可以作为幼虫的性别特征。

棉田与玉米田棉铃虫(Helicoverpa armigera Hübner)种群动态特征的比较

1998年在江苏丰县系统调查了棉田和玉米田中第三、四代棉铃虫的种群动态 ,用生命表方法比较了两种寄主田内棉铃虫种群的发育速率和存活率。结果表明 ,棉铃虫卵峰期至 4龄幼虫高峰期的历期在玉米田要比棉田快 4 d,并以产卵于玉米抽雄扬花期的发育最快。两类寄主田内平均存活率无显著差异 ,但产卵于玉米抽雄扬花期时 ,其卵至 6龄幼虫的存活率比产在其它阶段玉米上的存活率高。在江苏棉区目前的作物布局和耕作制度下 ,玉米田第三代棉铃虫是棉田第四代棉铃虫的重要虫源。

河北省棉铃虫(Helicoverpa armigera Hübner)种群数量的气象综合预报方法的研究

为了客观地反映棉铃虫种群数量变化与气候背景的关系规律 ,创建了棉铃虫气象多时段综合因子的因子组建方法 ;建立了贡献度权重修正的气象距离指标方法和模型 ;匹配以传统的多元回归模型 ,进行棉铃虫种群数量的气象监测和预报 ;将其自身生物潜能和气象条件影响相结合 ,建立了棉铃虫灾害的生物气象定量综合预报模型。在棉铃虫发生的气象条件评价和发生程度预测预报应用中 ,趋势准确率达到 93 %。

河北省不同地理区域的棉铃虫种群分布

随着黄河流域棉花种植面积的逐渐缩小,Bt棉花作为棉铃虫“诱杀陷阱”的作用逐渐减弱。为了明确河北省各作物种植结构调整后棉铃虫在不同地理区域内的种群分布特点,2018年和2019年利用性信息素诱捕技术,监测了5—9月河北省从南到北不同作物上棉铃虫成虫的种群数量。结果表明:(1)河北省棉铃虫种群发生数量大,并在多种寄主作物田中广泛分布,其中冀南地区棉田棉铃虫有4个成虫发生高峰期,高峰期诱捕虫量均达到100头/个(诱捕器)以上,最高达到了272.67头/个(诱捕器);(2)棉铃虫种群数量从南到北呈逐步递减趋势,南部、中部、北部的最高诱捕虫量分别为272.67、118.00和94.50头/个(诱捕器);(3)除棉田外,花生和玉米等作物田以及葡萄等果园的棉铃虫也需要引起足够重视。本研究结果明确了河北省新的种植结构布局下不同地理区域内棉铃虫的种群数量及其分布动态,可为华北地区不同作物布局下棉铃虫的区域性防治提供理论依据。

Commercial production of transgenic Bt insect-resistant cotton varieties and the resistance management for bollworm (Helicoverpa armigera Hubner)

There are currently three kinds of transgenic Bt insect-resistant cotton germplasm lines, Shanxi 94-24, Zhongxin 94 and R19, in China. They showed high resistance to the neonate larvae of bollworm (Helicoverpa armigera). Transgenic Bt insect-resistant cotton varieties or hybrids have been bred using the three kinds of germplasm lines as parents. Our researches reveal that there exist different expressions in resistant level at different developmental stages in the three categories of germplasm lines. When neonate larvae are fed with leaves of cotton plant at the seeding stage with less than 10 leaves on the main stem, the mortality of the neonate larvae is 100%, but the resistance level will decline at later season. When Bt gene has been transferred to the cotton genome, it can be steadily transferred to the progeny, the level of resistance to bollworm keeps fundamentally uniform. Such insects as tobacco budworm (Heliothis virencens) in laboratory directive selection are very apt to produce resistance

郭予元院士在棉花-害虫-天敌化学通讯研究中的学术贡献——纪念郭予元院士诞辰90周年

20世纪90年代棉铃虫大暴发,我国棉花产业和经济遭受重大损失,郭予元院士带领团队研究人员,深入探究棉铃虫的发生规律和控制策略,揭示了棉铃虫迁飞扩散规律及其与寄主植物互作关系,明确了转基因抗虫棉花生物安全和靶标害虫抗性机制,解析了棉花-棉铃虫-侧沟茧蜂三级营养间的化学通讯机制,使得大灾之年棉区棉铃虫为害得到有效控制,并对促进我国农业昆虫学基础研究起到了重要的学科引领作用。其中,对棉花-棉铃虫-中红侧沟茧蜂三级营养间化学通讯机制的研究,开创了棉铃虫治理新思路和新途径。本文回顾了郭予元院士在该领域研究中做出的重要贡献,主要包括棉花-棉铃虫-侧沟茧蜂三级营养通讯间关键挥发性化合物的鉴定,棉铃虫及其寄生性天敌中红侧沟茧蜂嗅觉行为分子机制的研究,棉花虫害诱导关键挥发物生物合成机制的探索,及基于三级营养关系设计昆虫行为调控剂在棉铃虫综合治理中的应用。上述研究成果为阐明棉铃虫及夜蛾科昆虫、中红侧沟茧蜂等膜翅目天敌寻找寄主的化学通讯机制奠定了坚实基础,为设计害虫绿色防控策略提供了新方向。

郭予元院士在棉铃虫区域性综合防治技术体系研究及应用中的学术贡献——纪念郭予元院士诞辰90周年

郭予元院士带领团队研究人员通过多年协同攻关研究,解析了棉铃虫发生为害规律和自然种群生命表机制,明确了棉铃虫对多种农药抗药性动态并应用于棉田抗药性治理,揭示了黄河流域棉区棉花对不同世代棉铃虫为害的补偿生长规律和防治策略,基于不同世代棉铃虫为害阈值和防治指标创建了准确预报二代棉铃虫发生数量的一代麦田扫网法,开展棉花种质资源抗病虫性鉴定并指导选育多抗棉花系列新品种。通过整合诱杀、选择性杀虫剂、生物农药与化学农药次序使用和局部精准施药等绿色防治技术,组建区域性棉花主要病虫害综合防治技术体系,棉区棉铃虫为害得到有效控制,引领了我国农作物主要病虫害综合防治技术的发展。本文简要回顾了郭予元院士在该领域研究中做出的主要历史贡献。

Inheritance of resistance to Helicoverpa armigera of 3 kinds of transgenic Bt strains available in upland cotton in China

There are 3 kinds of transgenic Bt strains, Shanxi 94-24, Zhongxin 94, and R19, in upland cotton in China. Their transgenic Bt insect-resistance cultivars or hybrids have been developed and grown by farmers. Genetic studies indicate that the resistance of the 3 transgenic Bt cotton strains to Helicoverpa armigera is controlled by one pair of non-allelic dominant genes. Linkage relationship between the resistant genes of R19 and Shanxi 94-24 transgenic Bt strains shows that they may be inserted in the same chromosome. FT hybrids crossed among the 3 strains show that high levels of protection from feeding damage are the same as that of their parents. Therefore, there is no co-suppression phenomenon in many transgenic plants. The results presented here afford a fundamental reliance in developing transgenic Bt insect-resistant cultivars and exploiting the heterosis of hybrids in upland cotton.

二代棉铃虫种群动态的地统计学分析

运用地统计学方法，分析了山东省滨州地区二代棉铃虫在1965-2004年间种群动态的时间序列结构特征和自相关性，根据决定系数尺。和Akaike’s Information Criteria（AIC）判别参数，筛选出最优拟合模型。结果表明：棉铃虫越冬蛹量、二代棉铃虫百株累计卵量、发生程度的最优拟合模型均是球形模型，呈聚集分布；三者的变程分别为10．41、12和12．06年，高度一致；三者在时间序列上的自相关性分别是53．22％、52．62％和69．06％；三者的结构特征引起的种群变异介于25％～75％，为中等程度的空间自相关性，其相关强度顺序是百株累计卵量〈越冬蛹量〈发生程度，随机部分引起的空间变异则相反。

棉铃虫6龄幼虫中肠与脂肪体微粒体P450酶系的比较

报道了棉铃虫 6龄幼虫中肠和脂肪体微粒体P45 0酶系的组成与加单氧酶活性。与脂肪体微粒体相比 ,中肠微粒体具有更高的细胞色素P45 0、细胞色素b5和NADPH -细胞色素P45 0还原酶含量 ,表现出较高的艾氏剂环氧化酶和对 -硝基苯甲醚O -脱甲基酶活性。SDS PAGE电泳显示 ,中肠与脂肪体微粒体介于P45 0分子量范围内 (4 5～ 6 0kDa)的蛋白图谱有所不同 ,反映出中肠和脂肪体微粒体蛋白组成存在差异。通过对 -硝基苯甲醚O -脱甲基酶的动力学分析发现脂肪体微粒体的对 -硝基苯甲醚O -脱甲基酶对底物有更强的亲和性 ,表明不同组织来源的P45 0同功酶存在质的不同。

用性信息素预测棉铃虫发生期的可靠性

利用棉铃虫（Ｈｅｌｉｃｏｖｅｒｐａ ａｍ ｉｇｅｒａ）性信息素诱蛾，预测下一代棉铃虫的卵高峰，幼虫孵化高峰，通过田间调查印证是准确的，它比黑光灯诱蛾以及田间调查方法简便，省工省时，指导化学农药防治时间准确，经济效益明显。可为棉铃虫发生期预测预报增添一种新的有效方法。

棉铃虫对转Bt基因棉的抗性及其治理策略研究进展

简述了苏云金杆菌Bacillusthuringiensis (Bt)毒素的作用方式及杀虫机理 ,分析了Bt棉种植过程中面临的生态风险。综述了昆虫对Bt毒素的抗性机理、监测方法及治理策略方面的研究进展。棉铃虫对Bt棉的抗性可能主要与中肠上皮细胞膜上的特异性结合受体中结合位点的改变有关。在多种抗性治理策略中 ,庇护所策略被公认为是目前最有效的并已广泛采用的抗性治理措施。应针对Bt棉在我国的种植情况 ,在棉铃虫还未在田间表现出抗性以前 ,制定合理的抗性预防。

棉铃虫乙酰胆碱酯酶cDNA片段的克隆和序列分析

Acetylcholinesterase (AChE) is the target of organophosphate and carbamate pesticides. Organophosphate resistance is worldspread in the cotton bollworm[Helicoverpa armigera (Hübner)]. With the degenerate primers we amplified a 281 bp cDNA fragment of acetylcholinesterase (AChE) gene in H. armigera by reverse transcription-polymerase chain reaction (RT-PCR) method using total RNA extracted from 4th larva as the template. The cDNA fragment was inserted into pGEMT vector and then cloned. The deduced amino acid sequence of AChE consisted of 94 residues. The sequence analysis indicated that the deduced amino acid sequence of the cDNA fragment shares high identity with AChE gene from other published insects and animals. The acquired sequence had 84%,79%,74%,70%,70%,72%,68%,61%,55% and 57% of amino acid residues identical to those of Leptinotarsa decemlineata(L.d.), Nephotettix cincticeps(N.c.),Anopheles stephensi(A.s.), Aedes aegypti(A.a.), Lucilia cuprina(L.c.), Drosophila melanogaster(D.m.), Musca domestica(M.d.), Meloidogyne incognita(M.i.), Torpedo californica(T.c.) and Gallus gallus(G.g.), respectively. All these results firmly established that the amplified cDNA fragment was the partial sequence of AChE gene in H. armigera. This is the first report of partial cDNA sequence of AChE in H. armigera.

F_1代法监测田间棉铃虫对转Bt基因棉的抗性

采用表达单价Cry1Ac毒素的转Bt基因棉棉叶喂饲法比较了棉铃虫Helicoverpa armigera(Hbner)抗、感亲本及正反交后代在Bt棉上5d的发育速率,确定棉铃虫在Bt棉上5d发育到2龄中期以上、体重≥0.6mg的个体作为判别抗性纯合子的标准。2006年采用F1代法在室内用Bt棉叶喂饲法检测河北省邱县Bt棉田棉铃虫对Bt棉的抗性等位基因频率。结果表明,127头田间雄虫中24头携带抗性基因,估测抗性等位基因频率为0.94(95%CI:0.044～0.145),该值为在国内首次检测到的高抗性等位基因频率。该地区长期大面积种植转单价Bt棉和缺少非Bt棉作为有效庇护区导致田间抗性快速进化,需要尽快采取有效的抗性治理策略。本文还讨论了影响大田产生抗性的因素以及田间存在的抗性风险等。