Gapless Genome Assembly of ZH8015 and Preliminary Multi-Omics Analysis to Investigate ZH8015's Responses Against Brown Planthopper Infestation

Accurate genomic information is essential for advancing genetic breeding research in specific rice varieties.This study presented a gapless genome assembly of the indica rice cultivar Zhonghui 8015(ZH8015)using Pac Bio HiFi,Hi-C,and ONT(Oxford Nanopore Technologies)ultra-long sequencing technologies,annotating 43037 gene structures.Subsequently,utilizing this genome along with transcriptomic and metabolomic techniques,we explored ZH8015's response to brown planthopper(BPH)infestation.Continuous transcriptomic sampling indicated significant changes in gene expression levels around 48 h after BPH feeding.Enrichment analysis revealed particularly significant alterations in genes related to reactive oxygen species scavenging and cell wall formation.Metabolomic results demonstrated marked increases in levels of several monosaccharides,which are components of the cell wall and dramatic changes in flavonoid contents.Omics association analysis identified differentially expressed genes associated with key metabolites,shedding light on ZH8015's response to BPH infestation.In summary,this study constructed a reliable genome sequence resource for ZH8015,and the preliminary multi-omics results will guide future insect-resistant breeding research.

Effects of Temperature on Functional Response of Anagrus nilaparvatae Pang et Wang (Hymenoptera:Mymaridae) on the Eggs of Whitebacked Planthopper,Sogatella furcifera Horvth and Brown Planthopper,Nilaparvata lugens Stl

Understanding the temperature affecting parasitic efficiency is critical to succeed in utilizing parasitoid as natural enemy in pest management. Laboratory studies were carried out to determine the effects of temperature on parasitoid preference of female Anagrus nilaparvatae Pang et Wang （Hymenoptera：Mymaridae） to the eggs of whitebacked planthopper （WBPH）, Sogatella furcifera Horváth and brown planthopper （BPH）, Nilaparvata lugens Stl to build a composite model describing changes in parasitic response along a temperature gradient （18, 22, 26, 30, 34°C）. The results showed that attack responses of A. nilaparvatae on WBPH and BPH were the best described by a Type II functional response. The two parameters, attack rates （a） and handling times （Th）, of A. nilaparvatae to both eggs were influenced by the temperature. The maximum attack rates to WBPH （1.235） and BPH （1.049） were at 26 and 34°C, respectively, and the shortest handling times to WBPH （0.063） and BPH （0.057） were at 30 and 26°C, respectively. However, the optimal temperature for parasitic efficiency of A. nilaparvatae to WBPH and BPH eggs was both at 26°C, which showed that the present microclimate temperature of the habitat in the paddyfield was beneficial to A. nilaparvatae and indicated that parasitic efficiency of A. nilaparvatae would be impaired by global warming.

High Temperature Modifies Resistance Performances of Rice Varieties to Brown Planthopper,Nilaparvata lugens(Stl)

To investigate the effect of temperature on the resistance characteristics of dce varieties with different resistance genes to brown planthopper （BPH）, Nilaparvata lugens （Stal）, the resistances of IR26 （Bphl） and IR36 （bph2） to BPH population in Hangzhou, China were monitored in greenhouse during September in 2007 and 2008 by using the standard seedling screening techniques （SSST） developed by the International Rice Research Institute （IRRI）. Furthermore, the changes in resistance of IR26 and IR36 to BPH, soluble sugar and oxalic acid contents in 25-day-old rice plants of susceptible variety TN1 and resistant varieties IR26 and IR36 were detected at five temperatures （22℃, 25℃, 28℃, 31℃ and 34℃）. IR26 completely lost resistance both in greenhouse and at the five tested temperatures. IR36 still had moderate resistance at natural temperature, but its resistance decreased gradually when the temperature increased from 25℃ to 34℃, and fully lost its resistance at 31℃ and 34℃. The highest durable resistance of IR26 and IR36 were recorded at 25℃. The soluble sugar content in plants of the three tested rice varieties increased with temperature increase, and the oxalic acid content increased with the temperature increase at first, maximized at 25℃, and then declined. Two-way ANOVA indicated significant effects of temperature and rice variety on contents of soluble sugar and oxalic acid in rice plants

Tolerance evaluation of rice varieties to the brown planthopper,Nilaparvata lugens feeding

The brown planthopper,Nilaparata lugens(Stl)(BPH)is one of the most important insect pests of rice in China and other east-southern Asian countries.Untilization of rice resistance varieties is one of the most econnomic and effective ways for

The forecasting models of brown planthopper Nilaparvata Lugens(stol)in Zhejiang Provence

Based on the historical data over 15 years from fivecounties including Xiaoshan,Longyou,Pujiang,Wenling,and Huangyan,Zhejiang Province,a se-ries of forecasting models were established by stepwise regression.These models could be used to pre-dict the population size and the level of the main en-dangering generation of brown planthopper(BPH)on late-season rice.After eight years validation,73models were established from 469 ones as a series ofmodels used as long,medium,and short term fore-casting.

Effects of nitrogen on the tolerance of brown planthopper,Nilaparvata Lugens, to adverse environmental factors

The effect of nitrogen content in rice plants on the tolerance of brown planthopper (BPH), Nilaparvata lugens Stal to high temperature, starvation and insecticide, was studied in the laboratory at International Rice Research Institute (IRRI), Philippines. Survival of nymphs and adults, fecundity and egg hatchability were significantly increased by the increase of nitrogen content in host plants at 38℃. Moreover, the survival of nymphs,fecundity and egg hatchability were significantly higher in BPH populations on rice plants with a high nitrogen regimen than those on rice plants with a low nitrogen regimen.Meanwhile, the tolerance of female adults to starvation and nymphs to growth regulator buprofezin on rice plants with a high nitrogen regimen were slightly increased. This indicates that the tolerances of BPH to adverse environmental stresses were positively increased by the application of nitrogenous fertilizer. The outbreak potential of BPH induced by the excessive application of fertilizer in rice fields was also discussed.

Genomic resources for the brown planthopper, Nilaparvata lugens： Transcriptome pyrosequencing and microarray design

The brown planthopper, Nilaparvata lugens is a pest of cultivated rice through- out Asia and is controlled using insecticides and/or resistant rice varieties. This species has developed resistance to many classes of insecticide and biotypes have developed that are vir- ulent against formerly resistant rice cultivars. Insects use a suite of detoxification enzymes, including cytochrome P450s, glutathione S-transferases and carboxyl/cholinesterases to defend themselves against plant secondary metabolites and pesticides. Pyrosequencing on the Roche 454-FLX platform was used to produce a substantial expressed sequence tag （EST） dataset to complement the existing Sanger sequenced ESTs in GenBank. A total of 78 959 reads were combined with the 37 392 publically available Sanger ESTs; these assembled into 8 911 contigs and 10 620 singletons. Analysis of the distribution of tenta- tive unique genes （TUGs） with the gene ontology for biological processes and molecular functions suggests that the 454 and Sanger EST assembly is broadly representative of the N. lugens transcriptome. The brown planthopper transcriptome was found to contain 31 TUGs encoding P450s, nine encoding glutathione S-transferases and 26 encoding car- boxyl/cholinesterases and many of these are putatively involved in the detoxification of xenobiotics. The Agilent eArray platform was used to construct an oligonucleotide mi- croarray populated with probes for ~ 19 000 unigene sequences, including all those known to encode detoxification enzymes. The genomic resources developed in this study will be useful to the community studying this crop pest and will help elucidate the molecular mechanism underlying insecticide resistance and planthopper adaptation to resistant rice cultivars.

Influence of Temperature on Symbiotic Bacterium Composition in Successive Generations of Egg Parasitoid, Anagrus nilaparvatae

Anagrus nilaparvatae is the dominant egg parasitoid of rice planthoppers and plays an important role in biological control. Symbiotic bacteria can significantly influence the development, survival, reproduction and population differentiation of their hosts. To study the influence of temperature on symbiotic bacterial composition in the successive generations of A. nilaparvatae, A. nilaparvatae were raised under different constant temperatures of 22 °C, 25 °C, 28 °C, 31 °C and 34 °C. Polymerase chain reaction-denaturing gradient gel electrophoresis was used to investigate the diversity of symbiotic bacteria. Our results revealed that the endophytic bacteria of A. nilaparvatae were Pantoea sp., Pseudomonas sp. and some uncultured bacteria. The bacterial community composition in A. nilaparvatae significantly varied among different temperatures and generations, which might be partially caused by temperature, feeding behavior and the physical changes of hosts. However, the analysis of wsp gene showed that the Wolbachia in A. nilaparvatae belonged to group A, sub-group Mors and sub-group Dro. Sub-group Mors was absolutely dominant, and this Wolbachia composition remained stable in different temperatures and generations, except for the 3rd generation under 34 °C during which sub-group Dro became the dominant Wolbachia. The above results suggest that the continuous high temperature of 34 °C can influence the Wolbachia community composition in A. nilaparvatae.

安徽省十种水稻主栽品种对褐飞虱的抗性鉴定

采用经过改良的国际水稻研究所标准苗期集团筛选法和成株期鉴定法,对安徽省内主栽的10个水稻品种的褐飞虱抗性进行了鉴定。苗期鉴定结果表明,在测试的10个品种中,高感褐飞虱9级的品种7个,感褐飞虱7级的品种3个。成株期的鉴定结果与苗期存在一定的差异,10个品种中,有6个品种的成株期抗性等级鉴定高于苗期,其余4个品种保持不变。

江苏省水稻褐飞虱对9种杀虫剂的抗性监测

褐飞虱是江苏省水稻上的重要害虫。采用稻茎浸渍法监测了2012年以来江苏省水稻褐飞虱对9种杀虫剂的抗性发展水平,结果表明,江苏省水稻褐飞虱种群对吡虫啉、噻虫嗪、噻嗪酮、吡蚜酮、毒死蜱、呋虫胺、烯啶虫胺、氟啶虫胺腈和三氟吡嘧啶等9种杀虫剂均产生了不同程度的抗药性,其中对吡虫啉、噻虫嗪和噻嗪酮的抗药性水平极高,对三氟吡嘧啶的抗性水平最低,提出强化抗药性水平监测,加强虫情监测预警,开发研究新药剂,提升科学用药水平等综合治理措施。

褐飞虱2009年秋季回迁的雷达监测及轨迹分析

褐飞虱Nilaparvata lugens(Stal)是水稻生产上重要的迁飞性害虫,研究其迁飞、扩散规律,为早期预警和有效防治提供科学依据。2009年4月27日至10月11日,在中国农业科学院植物保护研究所重大病虫害监测预警兴安雷达站内利用毫米波扫描昆虫雷达对褐飞虱的迁飞过程进行长期观测,高空探照灯诱虫器及佳多自动虫情测报灯诱虫器分别用来诱捕高空及地面的褐飞虱,对高空探照灯诱到的褐飞虱雌成虫随机挑选30头进行卵巢解剖,并结合大区环流和利用Hysplit_4模型进行轨迹分析,研究了褐飞虱的秋季回迁过程和虫源。结果表明:褐飞虱秋季回迁高峰期出现在9月28日至10月7日,高峰日为10月1日,高峰日内雷达回波主要在600～1100m范围内聚集成层,高空探照灯诱虫器内褐飞虱的数量达到了13620头;卵巢发育级别以1～2级为主。轨迹分析显示:本次回迁的褐飞虱主要来自湖南衡阳和永州等地,随东北气流向广西柳州、南宁和崇左等方向迁飞。轨迹推断与褐飞虱实发虫情基本吻合,通过毫米波扫描昆虫雷达确定了褐飞虱秋季回迁的高度,为毫米波扫描昆虫雷达早期投入到预测预报的实践中奠定了基础,对我国褐飞虱早期预警体系的建立将提供必要的技术支持。

普通野生稻(Oryza rufipogon Grif.)抗稻褐飞虱新基因的鉴定与利用

稻褐飞虱(BPH,NilaparvatalugensSt#l)是中国和世界稻区最严重的水稻害虫之一,发现和利用新抗性基因和进行抗性种质创新对于稻褐飞虱抗性品种的培育具有重要的意义。本研究进行了1200多份普通野生稻(OryzarufipogonGriff)种质对多种BPH生物型的抗性鉴定,获得了30份抗性资源,其中6份对分布于世界主要稻区的稻褐飞虱生物型1和2、孟加拉、湄公河(越南)、九龙江(越南)、潘特纳加(印度)等6种生物型或其中5种具有广谱高抗性。遗传分析证明了这些种质对BPH生物型2和九龙江生物型的抗性受2对重复作用隐性基因控制,对潘特纳加生物型的抗性受1对隐性基因控制,表明抗源对不同褐飞虱生物型具有不同的遗传机制。普通野生稻材料2183存在的2对隐性基因很可能是新发现的基因,因为在这些染色体区域还没报道有BPH抗性基因,这两对基因暂命名为bph18(t)和bph19(t)。研究总共培育出143份抗性创新种质和6份抗性品系或高产优质杂交水稻组合,这些优良的抗性创新种质为培育抗性新品种建立了坚实的基础。

低空急流对中国褐飞虱重大北迁过程的影响

低空急流是褐飞虱远距离迁飞的理想空中通道之一,为了揭示低空急流对褐飞虱北迁的动力作用机制,在全面分析2007年中国褐飞虱虫情资料的基础上,筛选出典型个例,结合相应的气象背景资料,对低空急流在褐飞虱北迁中的动力影响进行了系统的研究。研究表明:(1)低空急流作为一种大尺度天气系统,对2007年中国褐飞虱的重大北迁产生了重要的影响,这种影响体现在对虫源输送和降虫上;(2)低空急流的时空分布和强度变化对褐飞虱降虫时段、降虫范围、降虫量多少和主降虫区位置的选择有重要的影响;(3)逆推轨迹计算的结果显示:迁入主降区的褐飞虱是由低空急流输送的,这与其动力作用相吻合;(4)低空急流中的下沉气流对降虫区分布有着决定性的影响。

相空间重构与神经网络融合预测模型及其在害虫测报中的应用

针对混沌时间序列 ,建立了相空间重构和 BP神经网络融合预测模型。经实例验证 ,该方法能有效地提高预测精度 ,避免了一般混沌预测要求较长时间序列的缺陷 。

安庆褐飞虱近三个大发生年虫源和气候条件的比较分析

比较并分析安庆市1997，2005年和2006年褐飞虱Nilaparvata lugehs（Stal）大发生的虫源、气候条件。1997年，迁入期偏早，初迁虫量大，到7月26日止，单灯累计诱量为1228～8698头；7、8月份气温比历史均值低0．2～1．3℃，导致单季稻上基数适温协同暴发型；再迁补充虫源峰次较多，但9月份气温比历史均值低1．0℃，抑制了双季晚稻褐飞虱发生。2005年，迁入期较早，但初迁虫量低，到7月26日止，单灯累计诱量为200～3334头；7月中旬至8月份气温比历史均值低0．4～0．8℃，9月至10月中旬气温比历史均值高1．8～2．2℃，有利褐飞虱发生的气候条件长达3个月；同时，夏、秋季台风暴雨频繁，再迁补充虫源丰富，8月16日～9月25日每侯灯下≥1000头的回迁峰次多达5个，分别比1997年和2006年多1个和2个，导致多代连续重发。2006年，迁入期早，6月底以前的早迁虫量分别是1997年和2005年同期的6．4倍和2．1倍，初迁虫量大，到7月26日止，单灯累计诱量为1595～7181头；虽然7、8月份气温比历史均值高1．0～2．0℃，但单季稻田间小气候适宜，构成单季稻基数暴发型；再迁补充虫源峰次较少，但8月底～9月初短期内大量集中迁入，9月下旬至10月份气温异常偏高，高于历史均值1．5～3．0℃，引起晚稻持续重发。

水稻叶色突变对虫害发生影响的研究初报

为明确叶色标记水稻在生产中可能引起的虫害发生变化,本试验在使用和不使用农药防治的情况下,以常规品种嘉禾218为对照,对龙特甫B及其2个叶色突变系黄玉B、翠玉B田间虫害情况进行了调查。龙特甫B为正常绿叶籼稻品种,黄玉B、翠玉B全生育期分别表现黄色和翠绿色,在苗期、分蘖期和抽穗期,黄玉B较龙特甫B的叶绿素含量分别下降58.0%,48.4%和40.8%,翠玉B则分别下降39.5%,36.0%和29.5%。结果表明,秧田期2个叶色突变体上的稻蓟马虫量显著高于其亲本龙特甫B;本田期灰飞虱和褐飞虱的虫口数在不同材料间或差异不显著,或存在显著差异,但没有一定的规律性。但是,2个突变体受稻纵卷叶螟的危害显著轻于龙特甫B,表现为盛发期突变体受稻纵卷叶螟危害产生的虫苞数显著少于龙特甫B,而龙特甫B与嘉禾218之间没有显著差异;相反,2个突变体植株上白背飞虱的虫量显著大于龙特甫B,龙特甫B也显著大于嘉禾218。根据植株的农艺性状和叶绿素含量,以及虫害发生动态变化,笔者推测,造成叶色标记水稻稻纵卷叶螟危害变轻的原因可能与植株叶绿素含量下降,影响幼虫生长发育有关,但引起白背飞虱虫口增加的原因尚需进一步研究。本试验为首次对叶色标记水稻虫害发生情况进行研究,所得结果不但对完善叶色标记水稻生产体系具有指导意义,同时对研究害虫与水稻叶色之间的关系也具有理论价值。

褐飞虱在适应抗性水稻品种“IR26”过程中的氨基酸含量变化

本试验研究了褐飞虱在适应抗性水稻品种"IR26"过程中体内游离氨基酸含量的变化规律,结果表明,"IR26"植株的叶鞘和伤流液中氨基酸总量分别比感虫水稻品种"TN1"植株的低3.78%和3.05%。除苯丙氨酸和赖氨酸外,褐飞虱在"IR26"上取食第2代时体内其他氨基酸含量均升高,从第3代开始下降。饲养在"TN1"上的褐飞虱转移到"IR26"上取食后,其蜜露中氨基酸除天冬氨酸、谷氨酸和胱氨酸外,其他游离氨基酸含量均上升。而在"IR26"上取食3代的褐飞虱转移到"TN1"上取食,其蜜露中的苏氨酸、缬氨酸、精氨酸、天冬氨酸、丝氨酸、谷氨酸和甘氨酸含量下降,但氨基酸总量相差不大。

褐飞虱两种生物型体内能源物质及有关酶类的比较

采用室内繁殖的褐飞虱生物型Ⅰ与生物型Ⅱ的 5龄若虫和刚羽化的雌性成虫 ,研究其体内的能源物质含量以及解毒酶体系 (羧酸酯酶和乙酰胆碱酯酶 )和保护酶体系 (过氧化物酶、过氧化氢酶和超氧化物歧化酶 )的活性。结果显示 :①褐飞虱生物型Ⅰ体内糖元含量显著高于生物型Ⅱ (P <0 0 5 ) ,总脂没有差异 ;②生物型Ⅰ的羧酸酯酶活性比生物型Ⅱ低 ,乙酰胆碱酯酶活性则无明显差异 ;③生物型Ⅰ的超氧化物歧化酶活性和过氧化氢酶活性均比生物型Ⅱ低 (P <0 0 5 ) ,且随虫龄的增大而增高 ,而过氧化物酶活性则随虫龄增大而降低 。

两个褐飞虱海藻糖转运蛋白基因的结构及调控海藻糖代谢功能

【目的】海藻糖是昆虫中的主要血糖物质,在昆虫的发育及生理活动中发挥重要功能。其中,海藻糖转运蛋白(Tret)在将海藻糖从其生成组织(例如脂肪体)运输到其消耗组织的过程中起着重要作用。本研究通过分析褐飞虱(Nilaparvata lugens)两条Tret1的序列结构,进一步抑制NlTret1的表达,探讨这两个NlTret1在褐飞虱体内的生物学功能。【方法】以褐飞虱两条Tret1序列为研究对象,利用生物信息学技术分析其蛋白结构以及与其他昆虫之间的同源性。采用RNAi(RNA interference)技术将合成的外源dsRNA(double-stranded RNA)注射到实验室饲养褐飞虱种群体内,抑制其体内NlTret1的表达,分别在注射48 h后取材,抽取总RNA并用反转录试剂盒合成第一链cDNA,采用qRT-PCR(quantitative real-time PCR)技术检测dsNlTret1的干扰效果以及RNAi后褐飞虱体内海藻糖代谢通路中相关基因的表达,最后测定葡萄糖、海藻糖和糖原含量以及海藻糖酶活性。【结果】生物信息学分析表明,NlTret1-like X1和NlTret1-2 X1的开放阅读框长度分别为1920和1578 bp,分别编码639和525个氨基酸,预测蛋白分子量分别为69.29和58.71 kD,等电点分别为8.32和8.36;NlTret1-like X1和NlTret1-2 X1的二级结构主要包含螺旋和卷曲;保守结构域分析显示它们均属于MFS家族。进化分析结果显示,不同昆虫的Tret1蛋白具有较高的同源性,且褐飞虱与其他半翅目昆虫具有较近的亲缘关系;与注射dsGFP组相比,注射靶标基因的dsRNA后均能够显著沉默本基因的表达;褐飞虱体内糖原、葡萄糖在注射dsNlTret1-like X1和dsNlTret1-2 X1后,其含量均无显著变化,然而不同于注射dsNlTret1-2 X1组,在注射dsNlTret1-like X1后褐飞虱体内海藻糖含量极显著升高;干扰NlTret1-like X148 h后褐飞虱体内TPS1、TPS2、TRE1-1、TRE1-2和TRE2的表达均极显著下调;而干扰NlTret1-2 X148 h后褐飞虱体内TPS1、TPS2和TRE1-1的表达虽也极显著下降,但TRE1-2和TRE2极显著上调;在注射dsNlTret1-like X1后,试虫可溶性海藻糖酶和膜结合型海藻糖酶的活性均极显著降低,而在注射dsNlTret1-2 X1后无显著变化。【结论】褐飞虱的两个Tret1在不同组织间发挥着不同的功能,其中NlTret1-like X1在特异性转运海藻糖参与能量供应中起到更为显著的作用。研究结果有助于探索Tret1在昆虫或无脊椎动物中调控海藻糖代谢平衡的调节机制,可为将来通过调控血糖平衡来控制褐飞虱等害虫提供理论依据。

有机稻田内不同生态措施对褐稻虱种群的控制作用

应用害虫生态控制理论和方法,以抗性品种、施用有机肥、种植对天敌具有助迁或保护作用的植物为基础,将稻田放鸭、薇甘菊(MikaniamicranthaKunth)乙醇提取物、现代苦楝油(MeliaazedarachL.)等各项生态措施,科学、合理地组配成褐稻虱Nilaparvatalugens(Stl)种群生态控制系统,研究其对褐稻虱种群的控制作用。结果表明稻田放鸭对褐稻虱若虫具有60.92%的控制效果,现代苦楝油200倍对褐稻虱种群的作用优于薇甘菊乙醇提取物1gDW·100mL-1,不同生态措施组合对褐稻虱自然种群的控制作用显著,但其联合作用效果与组合组分不成正比例增长。所组建的生态措施组合可将褐稻虱种群数量降至经济阈值以下,完全可达到持续控制褐稻虱种群的目的。