温度对番茄潜叶蛾生长发育和繁殖的影响

【目的】番茄潜叶蛾Tuta absoluta是一种对番茄具有毁灭性危害的世界性入侵害虫,本研究旨在探索温度对入侵番茄潜叶蛾种群生长发育和繁殖的影响,为预测番茄潜叶蛾的分布区域、田间发生动态提供基础。【方法】在室内测定了番茄叶片上番茄潜叶蛾在15, 20, 25, 30和35℃ 5个恒定温度条件下各虫态的发育历期和存活率、繁殖力和种群增长参数,并应用不同模型分析发育速率、内禀增长率和净生殖率与温度的关系,估计发育起点温度、发育极限温度、发育最适温度、有效积温和年发生代数。【结果】在恒温15~30℃范围内,番茄潜叶蛾各虫态的发育历期随温度升高而逐渐缩短。25℃下幼虫期存活率、成虫前期存活率、雌虫总产卵量、净生殖率、内禀增长率和周限增长率均最大。在35℃下,卵的存活率骤降至11%,孵化的幼虫无法正常发育。卵期、幼虫期、蛹期、成虫前期、全世代的有效积温分别为104.17, 232.59, 129.87, 434.78和526.32日·度,该虫在新疆伊宁县和察布查尔锡伯自治县的理论发生代数为4~5代。基于发育速率与温度关系的模型与基于种群增长参数与温度关系的模型所计算的积温需求参数不同,基于内禀增长率求得的番茄潜叶蛾的发育起点温度、发育极限高温和发育最适温度分别为12.46, 30.40和27.36℃。【结论】入侵我国新疆地区的番茄潜叶蛾适温范围广泛,在我国大部分地区具有极高的扩散风险。     

新疆和云南番茄潜叶蛾种群对六种杀虫剂的敏感性及其与解毒酶活性的关系

【目的】番茄潜叶蛾Tuta absoluta 是新入侵我国的对番茄具有毁灭性危害的入侵害虫,目前入侵我国的番茄潜叶蛾种群对杀虫剂的抗性尚无报道。本研究旨在明确新疆和云南番茄潜叶蛾田间种群对6种常用杀虫剂的敏感性及其与解毒酶活性的关系。【方法】采用浸叶法测定6种常用杀虫剂对番茄潜叶蛾新疆和云南种群2龄幼虫的室内毒力。通过对2龄幼虫的生物测定确定3种增效剂［CYP450抑制剂胡椒基丁醚(PBO)、酯酶抑制剂磷酸三苯酯(TPP)和GST抑制剂丁烯二酸二乙酯(DEM)］对氯虫苯甲酰胺的增效作用。采用酶活性分析测定室内敏感种群和田间抗性种群(新疆种群) 2龄幼虫体内解毒酶［细胞色素P450酶(CYP450)、谷胱甘肽S-转移酶(GST)和羧酸酯酶(CarE)］活性,以确定杀虫剂抗性与解毒酶活性的关系。【结果】番茄潜叶蛾云南种群对6种杀虫剂的敏感性由高到低依次为甲维盐、溴虫腈、多杀菌素、茚虫威、氯虫苯甲酰胺和高效氯氰菊酯。新疆种群对6种杀虫剂的敏感性由高到低依次为甲维盐、溴虫腈、氯虫苯甲酰胺、多杀菌素、茚虫威和高效氯氰菊酯。与室内敏感种群相比,云南和新疆种群对氯虫苯甲酰胺的抗性水平最高,抗性倍数分别为212.7和169.3倍。生物测定结果表明,3种增效剂PBO, TPP和DEM均对氯虫苯甲酰胺无明显增效作用。酶活性测定结果表明,番茄潜叶蛾室内敏感种群和田间抗性种群之间2龄幼虫中CYP450, GST和CarE活性无显著差异。【结论】番茄潜叶蛾新疆和云南种群对测试的6种杀虫剂产生不同程度的抗性,对氯虫苯甲酰胺的抗性最高,番茄潜叶蛾对杀虫剂的抗性与解毒酶活性无关。本研究的结果对番茄潜叶蛾的田间防治和杀虫剂抗性治理具有指导意义。     

烟草潜叶蛾幼虫空间分布型及其应用研究

本文就烟草潜叶蛾幼虫空间分布型及其垂直分布规律进行了探讨,结果表明：烟草潜叶蛾幼虫在田间呈聚集分布,聚集强度不因种群密度的改变而改变,幼虫主要聚集分布在烟草下部第一段（4片叶）上;降集或随机分布在第二段上;随机分布在第三段上,此外,应用虫株率进行田间种群密度的估计,其中Wilson模型和Gerrard模型所配理论曲线的预测值与实测值显著适合,但Gerrard模型的抽样估计误差较Wilson模型的小,最后本文用Taylor式中的参数a,b确定理论抽样数及序贯抽样,其模型分别为。     

基于功能反应和两性生命表评价番茄潜叶蛾的取食能力和生长发育

【目的】番茄潜叶蛾Tuta absoluta是茄科作物重要的害虫。本研究旨在明确番茄潜叶蛾的取食能力、种内竞争及生长发育情况,为有效防控番茄潜叶蛾提供理论依据。【方法】在实验室条件下利用功能反应方程、自身干扰模型及两性生命表对番茄潜叶蛾的取食能力(取食量)、种内竞争作用(分摊竞争强度)、生长发育和繁殖参数(发育历期、成虫寿命、雌雄性比、单雌产卵量和存活率)及种群参数(内禀增长率、周限增长率、净增殖率及平均世代周期)进行测定。【结果】番茄潜叶蛾3和4龄幼虫取食番茄叶片的的功能反应均符合HollingⅡ型,其对番茄叶片的搜寻效率分别为0.448和0.363,处理时间分别为0.018和0.006 d,每日最大取食量分别为55.56和166.67 mg。在食物量一定的条件下,番茄潜叶蛾3和4龄幼虫间存在较强的种内竞争,且3龄幼虫的分摊竞争强度大于4龄幼虫的。通过两性生命表对番茄潜叶蛾的种群参数分析表明,取食番茄叶片时其内禀增长率、周限增长率、净增殖率及平均世代周期分别为0.09 d^-1, 1.09 d^-1, 19.80和32.92 d。【结论】番茄潜...     

番茄潜叶蛾对四唑虫酰胺的抗性选育及交互抗性研究

【目的】明确番茄潜叶蛾Tuta absoluta(Meyrick)对四唑虫酰胺的抗药性发展趋势及对7种杀虫剂的交互抗性,为四唑虫酰胺的田间应用提供理论依据。【方法】采用浸叶法,在室内用四唑虫酰胺对番茄潜叶蛾进行抗性选育汰选,评估了抗性发展趋势并研究了交互抗性。【结果】在室内经过14代11次汰选后,获得了抗性倍数为18.67倍的番茄潜叶蛾四唑虫酰胺抗性品系。番茄潜叶蛾对四唑虫酰胺抗性现实遗传力h2为0.1885,在致死率为50%-90%选择压力下,预计番茄潜叶蛾对四唑虫酰胺抗性增长10倍需要3.59-8.00代。番茄潜叶蛾抗四唑虫酰胺品系对茚虫威存在明显的交互抗性,抗性倍数为8.89;对甲维盐、苏云金芽孢杆菌（Bt)存在负交互抗性,抗性倍数分别为0.80和0.25;对氯虫苯甲酰胺、多杀菌素、毒死蜱和高效氯氟氰菊酯不存在交互抗性,抗性倍数分别为3.58、2.39、1.80和1.73。【结论】用四唑虫酰胺防治番茄潜叶蛾存在抗性风险,番茄潜叶蛾四唑虫酰胺抗性品系会与其他药剂产生交互抗性,以上结果可为田间科学使用四唑虫酰胺和合理轮换用药提供理论依据。     

番茄潜叶蛾卵黄原蛋白受体基因TaVgR在生殖发育调控中的作用

【目的】本研究旨在明确卵黄原蛋白受体(vitellogenin receptor, VgR)在番茄潜叶蛾Tutaabsoluta生殖发育过程中的功能,为潜叶类害虫的绿色防控提供候选靶标。【方法】基于番茄潜叶蛾转录组数据,采用RT-PCR扩增TaVgR基因cDNA全序列,并进行生物信息分析;通过RT-qPCR分析TaVgR在番茄潜叶蛾不同发育阶段(1-4龄幼虫、1-7日龄雌蛹和雌成虫)和雌成虫不同组织(头、体壁、前肠、中肠、后肠、卵巢、脂肪体和马氏管)中的表达模式;进一步利用RNAi抑制番茄潜叶蛾雌蛹体内TaVgR的表达,并观测沉默TaVgR基因后番茄潜叶蛾卵巢发育及繁殖力的变化。【结果】克隆获得番茄潜叶蛾TaVgRcDNA(GenBank登录号: MZ682118)序列,其开放阅读框序列长5 496 bp,编码1 831个氨基酸,推测的蛋白分子量约为206 kD,等电点为5.17,信号肽包含N-端前18个氨基酸残基,并具有典型LDLR家族蛋白保守功能域。RT-qPCR结果显示,TaVgR转录水平随着番茄潜叶蛾龄期的增加逐渐上升,雌成虫羽化后达到最高水平;TaVgR在番茄潜叶蛾雌成虫的卵巢中表达量最高。TaVgR RNAi对初期雌蛹中TaVgR的表达抑制率为62.04%~72.55%,导致卵黄蛋白在卵巢中的沉积受阻,卵巢管和卵粒长度缩短,成虫10日单雌总产卵量及后代卵孵化率降低,最终引起番茄潜叶蛾繁殖力下降。【结论】TaVgR基因在番茄潜叶蛾雌成虫和卵巢中高表达,且沉默该基因严重阻碍其卵巢发育和降低繁殖力。本研究为开发以VgR基因作为靶标的鳞翅目害虫防治新技术奠定了理论基础。     

杨扇舟蛾卵和幼虫的空间分布型及抽样技术

研究了杨扇舟蛾Clostera anachoreta(Fabricius)卵和幼虫的空间分布型及抽样技术,结果表明杨扇舟蛾卵和幼虫在杨树林的分布型均为聚集型中的负二项分布。几种抽样方法中,卵以棋盘式最好,幼虫以平行线法最好。同时建立了杨扇舟蛾卵的下层抽样模型为y=2.4481x 0.4243;幼虫的中、下层抽样模型为y=2.4605x 3.9126。     

重大潜在入侵害虫番茄潜叶蛾的SS-CoI快速检测技术

【背景】番茄潜叶蛾是源自南美洲的一种最具毁灭性的世界性入侵害虫,其适生区范围广,且与其他潜叶类昆虫难以准确、快速识别。【方法】以田间常见的其他6种潜叶类害虫为对照,采用基于mtDNACOl基因的种特异性SS—COI方法,研究番茄潜叶蛾快速分子检测技术。【结果】种特异性检测结果显示,SS-COl引物只对番茄潜叶蛾mtDNA具有扩增能力,对美洲斑潜蝇、南美斑潜蝇、三叶草斑潜蝇、葱斑潜蝇、豌豆潜叶蝇、桃潜叶蛾等其他潜叶类害虫不具有扩增效果。该引物不仅对成虫和单粒卵具有很好的扩增效能,对单根触角、头部、胸部、腹部以及翅和足等成虫残体亦具有同样的扩增能力,其最低检出阈值为312．5Pg·μL^-1。【结论与意义】该方法在有效防范番茄潜叶蛾侵入我国,保障农业生产安全和生态环境安全中意义重大。     

重大潜在入侵害虫番茄潜叶蛾的SS-COⅠ快速检测技术

【背景】番茄潜叶蛾是源自南美洲的一种最具毁灭性的世界性入侵害虫,其适生区范围广,且与其他潜叶类昆虫难以准确、快速识别。【方法】以田间常见的其他6种潜叶类害虫为对照,采用基于mtDNA COⅠ基因的种特异性SS-COⅠ方法,研究番茄潜叶蛾快速分子检测技术。【结果】种特异性检测结果显示,SS-COⅠ引物只对番茄潜叶蛾mtDNA具有扩增能力,对美洲斑潜蝇、南美斑潜蝇、三叶草斑潜蝇、葱斑潜蝇、豌豆潜叶蝇、桃潜叶蛾等其他潜叶类害虫不具有扩增效果。该引物不仅对成虫和单粒卵具有很好的扩增效能,对单根触角、头部、胸部、腹部以及翅和足等成虫残体亦具有同样的扩增能力,其最低检出阈值为312.5 pg·μL-1。【结论与意义】该方法在有效防范番茄潜叶蛾侵入我国,保障农业生产安全和生态环境安全中意义重大。     

基于线粒体COⅠ基因的番茄潜叶蛾群体遗传结构分析

【目的】番茄潜叶蛾Tuta absoluta(Meyrick)是番茄作物上的重大害虫,自入侵我国以来,已经造成了严重的经济损失,因此为了追踪我国番茄潜叶蛾的遗传分化进程,分析其与世界其它地理种群的遗传关系,本研究对番茄潜叶蛾种群的遗传结构进行了分析。【方法】研究采用线粒体COⅠ基因作为分子标记,分别对COⅠ基因同源性、遗传变异、遗传多样性、生物分子变异组成进行了分析,最后构建了世界范围内的系统发育树。【结果】结果显示,我国甘肃和宁夏地区的地理种群已经发生了可遗传变异,其中甘肃出现了两种突变单倍型（China:GSLZ;China:GSLZ）,宁夏为一种突变单倍型（China:NXWZ）;全球番茄潜叶蛾地理种群共检测到28个多态位点,存在18种单倍型,以塞内加尔地理种群单倍型最丰富,达10种,其次为肯尼亚;我国地理种群存在2个转换突变的简约信息位点,共3种单倍型,推测我国番茄潜叶蛾已经形成了一定的群体结构,但仍然处于入侵“瓶颈期”;总体而言,非洲番茄潜叶蛾遗传多样性最高,其次分别为南美洲和亚洲;分子生物学方差分析显示,引起种群变异的主要因素存在于种群内部,变异率占97.99%。系统发育分...     

Degradation and conversion of somatostatin in normal and diabetic rats in vivo and in vitro

Plasma somatostatin-like immunoreactivity in the portal and jugular veins of streptozotocin diabetic rats was compared with that in normal control rats. In the diabetic group, somatostatin levels in the portal (p less than 0.05) and jugular (p less than 0.01) veins were both elevated compared with those in the control group. Moreover, the degree of elevation was greater in the jugular vein than in the portal vein. To further investigate the role of the liver in the clearance of somatostatin-28 in vivo, 2 micrograms of somatostatin-28 was administered as a bolus into the external jugular vein of intact and functionally hepatectomized rats. The mean half-time of somatostatin-28 was significantly longer in intact diabetic rats than in controls (p less than 0.05). The functional hepatectomy did not cause a significant difference in the half-time in diabetic rats but made it longer in control rats. These results suggest that the longer half-time of somatostatin-28 in diabetic rats in vivo is due to its slower hepatic clearance. The hepatic clearance of somatostatin-28 and somatostatin-14 was further studied in vitro using a recirculating liver perfusion method. The hepatic clearance of 1.2 nM of either somatostatin-28 or somatostatin-14 was significantly lower in diabetic rats than in controls (p less than 0.01). This indicates that elevated plasma somatostatin levels in diabetic rats are caused at least in part by decreased hepatic clearance of somatostatin.(ABSTRACT TRUNCATED AT 250 WORDS)     

Production of arsine and methylarsines in soil and in culture

Arsenate, arsenite, monomethylarsonate, and dimethylarsinate were added to different soils, and evolution of gaseous arsenical products was determined over 3 weeks. Arsine was produced in all three soils from all substrates, whereas methylarsine and dimethylarsine were produced only from methylarsonate and dimethylarsinate, respectively. At least three times more arsine than dimethylarsine was produced in soil incubated with dimethylarsinate. Resting cell suspensions of Pseudomonas and Alcaligenes produced arsine as the sole product when incubated anaerobically in the presence of arsenate or arsenite. In all instances, no trimethylarsine was observed, nor could any evidence be shown for the methylation of any arsenical substrate in soil or in culture. It was concluded that reduction to arsine, not methylation to trimethylarsine, was the primary mechanism for gaseous loss of arsenicals from soil.     

Growth and mitogenic effects of arylphorin in vivo and in vitro

In insects, developmental responses are organ- and tissue-specific. In previous studies of insect midgut cells in primary tissue cultures, growth-promoting and differentiation factors were identified from the growth media, hemolymph, and fat body. Recently, it was determined that the mitogenic effect of a Manduca sexta fat body extract on midgut stem cells of Heliothis virescens was due to the presence of monomeric alpha-arylphorin. Here we report that in primary midgut cell cultures, this same arylphorin stimulates stem cell proliferation in the lepidopterans M. sexta and Spodoptera littoralis, and in the beetle Leptinotarsa decemlineata. Studies using S. littoralis cells confirm that the mitogenic effect is due to free alpha-arylphorin subunits. In addition, feeding artificial diets containing arylphorin increased the growth rates of several insect species. When tested against continuous cell lines, including some with midgut and fat body origins, arylphorin had no effect; however, a cell line derived from Lymantria dispar fat body grew more rapidly in medium containing a chymotryptic digest of arylphorin.     

Antiplatelet and antithrombotic activities of purpurogallin in vitro and in vivo

Enzymatic oxidation of pyrogallol was efficiently transformed to an oxidative product, purpurogallin (PPG). Here, the anticoagulant activities of PPG were examined by monitoring activated partial thromboplastin time (aPTT), prothrombin time (PT), and the activities of thrombin and activated factor X (FXa). And, the effects of PPG on expression of plasminogen activator inhibitor type 1 (PAI-1) and tissue-type plasminogen activator (t-PA) were evaluated in tumor necrosis factor (TNF)-α activated human umbilical vein endothelial cells (HUVECs). Treatment with PPG resulted in prolonged aPTT and PT and inhibition of the activities of thrombin and FXa, as well as inhibited production of thrombin and FXa in HUVECs. In addition, PPG inhibited thrombin-catalyzed fibrin polymerization and platelet aggregation. PPG also elicited anticoagulant effects in mice. In addition, treatment with PPG resulted in significant reduction of the PAI-1 to t-PA ratio. Collectively, PPG possesses antithrombotic activities and offers a basis for development of a novel anticoagulant. [BMB Reports 2014; 47(7): 376-381]     

Growth and reproduction of Arabidopsis thaliana in relation to storage of starch and nitrate in the wild-type and in starch-deficient and nitrate-uptake-deficient mutants

We have investigated the interactions between resource assimilation and storage in rosette leaves, and their impact on the growth and reproduction of the annual species Arabidopsis thaliana. The resource balance was experimentally perturbed by changing (i) the external nutrition, by varying the nitrogen supply; (ii) the assimilation and reallocation of resources from rosette leaves to reproductive organs, by cutting or covering rosette leaves at the time of early flower bud formation, and (iii) the internal carbon and nitrogen balance of the plants, by using isogenic mutants either lacking starch formation (PGM mutant) or with reduced nitrate uptake (NU mutant). When plants were grown on high nitrogen, they had higher concentrations of carbohydrates and nitrate in their leaves during the rosette phase than during flowering. However, these storage pools did not significantly contribute to the bulk flow of resources to seeds. The pool size of stored resources in rosette leaves at the onset of seed filling was very low compared to the total amount of carbon and nitrogen needed for seed formation. Instead, the rosette leaves had an important function in the continued assimilation of resources during seed ripening, as shown by the low seed yield of plants whose leaves were covered or cut off. When a key resource became limiting, such as nitrogen in the NU mutants and in plants grown on a low nitrogen supply, stored resources in the rosette leaves (e.g. nitrogen) were remobilized, and made a larger contribution to seed biomass. A change in nutrition resulted in a complete reversal of the plant response: plants shifted from high to low nutrition exhibited a seed yield similar to that of plants grown continuously on a low nitrogen supply, and vice versa. This demonstrates that resource assimilation during the reproductive phase determines seed production. The PGM mutant had a reduced growth rate and a smaller biomass during the rosette phase as a result of changes in respiration caused by a high turnover of soluble sugars ( Caspar et al. 1986 ; W. Schulze et al. 1991 ). During flowering, however, the vegetative growth rate in the PGM mutant increased, and exceeded that of the wild-type. By the end of the flowering stage, the biomass of the PGM mutant did not differ from that of the wild-type. However, in contrast to the wild-type, the PGM mutant maintained a high vegetative growth rate during seed formation, but had a low rate of seed production. These differences in allocation in the PGM mutant result in a significantly lower seed yield in the starchless mutants. This indicates that starch formation is not only an important factor during growth in the rosette phase, but is also important for whole plant allocation during seed formation. The NU mutant resembled the wild-type grown on a low nitrogen supply, except that it unexpectedly showed symptoms of carbohydrate shortage as well as nitrogen deficiency. In all genotypes and treatments, there was a striking correlation between the concentrations of nitrate and organic nitrogen and shoot growth on the one hand, and sucrose concentration and root growth on the other. In addition, nitrate reductase activity (NRA) was correlated with the total carbohydrate concentration: low carbohydrate levels in starchless mutants led to low NRA even at high nitrate supply. Thus the concentrations of stored carbohydrates and nitrate are directly or indirectly involved in regulating allocation.     

Activity of native and dextran-modified hyaluronidase in in vitro and in vivo systems

Modified hyaluronidase derivatives have been obtained. Covalent coupling of the enzyme with aldehyde dextran results in 65-85% protein binding to the carrier, residual catalytic activity accounting for 90-100% of the baseline. Modified hyaluronidase is more thermostable than the native enzyme. The data on intravenous drug distribution in the mouse organs are promising and ensure effective use of modified hyaluronidase for the treatment of pulmonary diseases.