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1.
室内恒温条件下以人工饲料饲养的嗜卷书虱 Liposcelis bostrychophila Badonnel成虫,分别在35%和55%CO_2。(21%O_2,N_2作为平衡气体使用)组配的气调环境中以70%的选择压力处理,以选育其抗高CO_2气调性。选育至30代获得抗性品系HCC_1和HCC_2,以LT_50为标准,其抗性倍数分别达4.6和5.3倍。整个选育过程中,气调暴露时间对数值与死亡率机率值间的回归直线基本平行,且斜率值均低于敏感基线的斜率值,这表明嗜卷书虱对高CO_2抗性发展的基因潜能至第30代仍未耗尽。两个抗性品系的抗性均不太稳定,去除选择压力后抗性显著下降,且两抗性品系均具有繁殖不利性即适合度缺陷。以净增值率为指标衡量,HCC_1和HCC_2相对于敏感品系分别具有0.52和0.45的适合度。  相似文献   

2.
嗜卷书虱成虫于28°C、70%—80%RH条件下,在35%CO2。和1%O2。组配的气调环境中连续暴露30代,选择压力保持在70%左右,以选育其抗气调性。至第30代,以LT50。为指标衡量其抗性倍数达5.6倍。生化分析表明,抗性选育过程中离体羧酸酯酶(CarE)和超氧化物歧化酶(SOD)活力均随选育代数的增多而显著增强,且酶活力与抗气调水平显著相关。第30代,抗性品系(CA-R)的CarE和SOD活力分别是敏感品系(CA-S)的4.06和5.22倍。两品系暴露于气调环境中,其CarE活力均受抑制,但对CA-S品系的抑制率显著强于CA-R品系。短时间的气调暴露对SOD具有诱导作用,但诱导作用的时间及强度CA-R品系明显长(强)于CA-S品系。离体过氧化氢酶(CAT)活力也随着抗气调性的增强而增强,但两着之间并无显著的相关性。抗性选育过程中离休酸性磷酸酯酶(ACP)和碱性磷酸酯酶(ALP)活力均未发生明显的变化。过氧化物酶(POD)在两品系中均未检测出。由此看出,CarE和SOD活力增强是嗜卷书虱抗气调性形成的主要机制,CAT可能对低氧气调抗性的形成具有辅助作用。  相似文献   

3.
CO2浓度加倍对辽东栎维管组织结构的影响   总被引:3,自引:0,他引:3       下载免费PDF全文
以孙东栎(Qucrcus liaotungensis)的13年生幼树为材料,分别培养大气CO2浓度加倍(700μ1.L^-1)与对照(350μ1.L^-1)的开顶式熏气室中,研究CO2浓度升高对其茎次生木质部和次生韧皮部结构的影响。结果表明:经CO2 倍处理的身份人生长季内,聍东栎的年轮宽度明显增加,为对照的300%、370%,其中晚材宽度的增加更9为显著 ,为对照的750%~830%。另外 ,晚  相似文献   

4.
提高CO2浓度对两种亚热带树苗光合作用的影响   总被引:15,自引:0,他引:15  
鼎湖山季风常绿阔叶林的主要优势乔木树种裂壳锥(Castanopsisfissa (Cham p.ex Benth.) Rehd.etWils.)和荷木(Schim a superba Gardn.etCham p.)幼苗,盆栽于自然条件(CO2 浓度350 μL·L- 1)或高CO2 浓度为500 μL·L- 1和空气CO2(350 μL·L- 1)的半开顶式气罩中。在生长最旺盛的6~9 月份,高浓度CO2 条件下生长的叶片,其光合速率比在自然条件下生长的提高79% ~95% 。当叶片在350 μL·L- 1和500 μL·L- 1的CO2 浓度下测定时,其光合速率无明显差异。高浓度CO2 下生长的叶片其光合速率-CO2 浓度响应曲线比对照(350 μL·L- 1)高,叶绿素和类胡萝卜素含量低,但叶绿素a 和b 的比值及类胡萝卜素和叶绿素的比值不变。高浓度CO2 下生长的叶片气孔导度明显降低。两种植物在85 d 的高浓度CO2 的生长过程中,并未出现光合速率下调现象  相似文献   

5.
磷化氢、二氧化碳混合气体对腐食酪螨成螨的生物学效应   总被引:7,自引:0,他引:7  
本文研究结果表明:腐食酪螨Tyrophagusputrescentiae(Schrank)成螨在0%、8%、16%(容积比)CO2气体中耗氧量随CO2浓度的增加而增加,当在32%、64%CO2气体中,该成螨的耗氧量反倒低于其在正常大气中的耗氧量。在0%、8%、16%、32%、64%CO2与0.05mg/LPH3混合气体中该成螨对PH3的吸收量分别为1.11±0.92、1.79±0.56、5.14±1.13、7.60±1.80、8.08±0.85μg/hr’g,在同一CO2浓度条件下试螨对PH3的吸收量在高浓度PH3(0.45mg/L)中明显大于在低浓度PH3(0.05mg/L)中,但PH3吸收量的增加倍数远远低于PH3浓度的增加倍数。PH3对该螨过氧化氢酶的抑制体内酶高于离体酶,细胞色素c氧化酶受PH3抑制则相反。被PH3抑制的过氧化氢酶和细胞色素C氧化酶活性恢复时间分别为二周和一周。本文还对PH3的可能杀螨机理及CO2在此过程中的作用进行了讨论  相似文献   

6.
动脉平滑肌细胞(sm ooth m uscle cell,SMC)是动脉粥样硬化(atherosclerosis,AS)斑块中的主要细胞,它的增殖在AS形成过程中极其重要.利用体外培养的人主动脉SMC,观察了天然高密度脂蛋白(native high density lipoprotein,N-HDL)及氧化修饰HDL(oxidized HDL,OX-HDL)对培养人主动脉SMC cyclin D1(细胞周期蛋白D1)基因转录表达的影响.结果表明:(1)N-HDL对SMCcyclin D1基因表达无影响(P> 0.05);(2)OX-HDL使SMCcyclin D1基因表达显著增强(P<0.01),其表达量随时间(2、12、24 h)延长而增加.上述结果表明,OX-HDL的致AS作用可能与其刺激SMCcyclin D1基因表达增加有关.  相似文献   

7.
6BA诱导的带正电荷的葡萄叶过氧化物酶   总被引:1,自引:0,他引:1  
河岸葡萄叶的带正电荷过氧化物酶(cationic peroxidase, CPOD) 可受6BA 诱导,但盐、H2O2 或Fe2++ H2O2 均使叶片CPOD 活性明显下降,而高浓度的无机盐明显刺激纯CPOD 活性增加。在以愈创木酚为底物时CPOD 最适pH 为4 .60 ~5 .75 ,对H2O2 的表观Vmax 和Km 值分别为110 U/mg 蛋白和1 .15m mol/L。  相似文献   

8.
在繁殖棚内昼夜施放CO2,使棚内CO2浓度保持在800±100μlL-1,对三种澳大利亚园林植物:Chamelauciumuncinatum、Correareflexa和Prostantherainctsa进行插条试验。结果表明:高浓度CO2处理的Chamelauciumuncinatum和Correareflexa插条干物质重量和淀粉含量显著增加,使插条出根早、出根率高和根量多,据后40d的插条出根率分别比对照高26.6%和33.4%.然而,同样的CO2处理对Prostantheraincisa的插条没有明显影响。这可能是由于后者对CO2处理不敏感之故。  相似文献   

9.
报道了嗜卷书虱对高二氧化碳,低氧气调抗性形成过程中能源物质的积累以及抗性形成后在气调胁迫下能源物质的利用情况。结果表明随着抗性水平的提高。嗜卷书虱体内甘油三酯,多糖以及游离氨基酸含量均显升高。在气调胁迫环境下,嗜卷书虱抗性品系能源物质的消耗率明显低于敏感品系,甘油三酯的积累以及在气调摁迫下缓慢消耗可能是其抗气调性的主要内在机理之一。  相似文献   

10.
用分子筛(岛津DIOL-150柱)和阳离子交换(岛津WCX-1柱)高效液相色谱从虎纹捕鸟蛛(Selenocosmiahuwena)毒液中分离提纯透明质酸酶(Hyaluronidase,EC3.2.1.35).经等电聚焦电泳为一条带,pI=7.2.经SDS-聚丙烯酰胺凝胶电泳测得分子量为40kD,经凝胶过滤测得分子量为40.7kD。以透明质酸为底物时在pH3.5─5.5范围内有较大活性,最适pH值为4.0;在pH4.5─6.0范围内稳定,在反应温度为30─60℃时有较大活性,最适温度为50℃;对热稳定,0.15mol/L的NaCl对酶活性有一定的稳定作用.3%的肝素、500μmol/L的Hg~(2+)、Fe~(2+)、Cu~(2+)对酶活性有明显的抑制作用。  相似文献   

11.
Abstract Adults of the psocid Liposcelis bostrychophila Badonnel were exposed to atmospheres containing 35% and 55% CO2 for 30 generations to select strains resistant to high CO2 content (HCC). Selection pressure was maintained at around 70% of mortality. At the 30th generation, comparison of sensitivities between the selected strains (HCC1 and HCC2) and the original susceptible strain (MA-S) revealed a resistance factor (RF) at the 50% mortality level (LT50) of 4. 6-and 5. 3-folds, respectively. Throughout the selection process, log-time against probit-mortality lines remained roughly parallel and the slopes remained lower than that of MA-S strain until the last generation. It is inplied that the genetic potential of L. bostrychophila to develop resistance to CO2 was not exhausted until the 30th generation. Removal of selection pressure for 5 generations from 2 sub-populations of two selected strains from the 25th generation caused significant reduction in resistance. In the absence of MAs exposure, the two selected strains (HCC1 and HCC2) possessed the fitness defect. HCC1 and HCC2 were calculated by R0 to have a fitness value of 0. 52 and 0. 45 relative to MA-S.  相似文献   

12.
Abstract. The metabolic rates, as expressed by oxygen (O2) consumption, carbon dioxide (CO2) production, and losses in wet and dry weights, were examined for adults of three strains of the red flour beetle Tribolium castaneum (Herbst), during exposure to two modified atmospheres (MAs). Exposure of a strain selected for resistance over twenty-one generations to an atmosphere of 65% CO2, 20% O2 and the balance nitrogen (N2), termed a high carbon dioxide concentration atmosphere (HCC) and exposure of an unselected strain to HCC, showed considerable levels of aerobic metabolism during exposure. For the unselected strain water loss and mobilization of energy reserves were rapid and mortality was followed by rapid desiccation. For the HCC-resistant strain water balance was maintained and energy reserves were utilized more slowly over a prolonged period. Exposure of a strain selected for resistance over twenty-one generations to a low oxygen concentration atmosphere (LOC) of 0.5% O2 in N2, and an unselected strain to LOC, revealed that even at 0.5% O2, metabolism was largely aerobic in both strains. Maintenance of water balance was not a major factor causing mortality of either strain during exposure to LOC. In air, metabolic rates of both the resistant strains were lower than that of the unselected strain.  相似文献   

13.
嗜卷书虱抗气调品系的选育及其适合度研究   总被引:2,自引:0,他引:2  
于恒温条件下以人工饲料饲养的嗜卷书虱Liposcelis bostrychophila,在35% CO2和1% O2组配的气调环境中以50%左右的选择压力处理,以选育其抗气调性。至30代获得抗性品系(CA-R),抗性倍数达5.6倍,且有继续增强的基因潜能。该抗性品系对气调的抗性不太稳定,在无选择压力的情况下经室内5代饲养,抗性衰退了63.2%。CA-R品系与敏感品系在无气调选择压力的条件下相比具有一定程度的繁殖不利性;但没有发现CA-R品系在生长发育特性上的不利性。以净增殖率来衡量,CA-R品系相对于敏感品系具有0.39的适合度。  相似文献   

14.
本试验在室内对甜菜夜蛾Spodoptera exigua(Hübner)武汉敏感品系进行了8代群体汰选后分别于9、10、12代采用了单对汰选。结果表明虫酰肼处理后各单对品系后代幼虫存活率发生明显分离,F9(s1)、F10(s2)和F12(s3)代幼虫平均存活率分别为48.34%、11.72%和2.37%,筛选后分别为84.00%、83.33%和7.29%。经过12代汰选后,汰选品系抗性倍数为敏感品系的5.24倍,且单对汰选世代对虫酰肼的抗性发展较快,其抗性倍数分别是群体汰选的1.27、1.67和1.38倍。比较单对汰选世代与群体汰选世代某些生物学特性,显示单对汰选世代并不存在生长发育和生殖不利性,表明在虫酰肼群体汰选中穿插几代单对汰选可以加速抗性品系的选育。汰选品系相对于敏感品系具有0.31的适合度,表明甜菜夜蛾对虫酰肼产生抗性后存在适合度缺陷。  相似文献   

15.
Abstract Adults of the psocid Liposcelis bostrychophila were exposed to an atmosphere containing 35% CO2 and 1% O2 for 30 successive generations at 28 C and 70%–80% RH in order to select a resistant strain to controlled atmosphere (CA). At the 30th generation the resistance factor (LT50 for selected generation / LT50 for non-selected generation) reached to 5. 6-folds. The results of biochemical assays showed that the activities of carboxylesterase (CarE) and superoxide dismutase (SOD) in vitro increased considerably from generation to generation during the selection process, and they were closely correlated with the resistance levels. At the 30th generation, the CarE and SOD activities in the resistant strain to CA (CA-R) were 4. 06-and 5. 22-folds as much as those in the susceptible strain to CA (CA-S), respectively. Exposure to CA resulted in decrease in CarE activity; however, the decreasing range for CA-S was significantly greater than that for CA-R. CA had induction effect on SOD within short time, but for CA-R the induction time was longer and activity induced was higher than CA-S. Catalase (CAT) activity was also raised with the resistance development, but no statistical relationship was found between CAT activity and CA resistance. No significant difference of both acid phosphatase (ACP) and alkaline phosphatase (ALP) was found in CA-R and CA-S during the selection process. Peroxidase (POD) activity was not detected in L. bostrychophila. These suggest that the major mechanism responsible for CA resistance appears to be the enhanced CarE and SOD activities, and probably CAT plays an additionary role to adopt low O2 concentration in CA resistance.  相似文献   

16.
Divergent lines selected artificially for many generations make it possible to answer two questions: (1) whether genetic variation still exists within the selected population; and (2) whether the selection itself is costly for the selected strain. In previous studies, the red flour beetle Tribolium castaneum was divergently selected artificially for duration of death-feigning, and strains selected for longer (L-strain) and shorter (S-strain) durations of death-feigning have been established (Miyatake et al. 2004, 2008). Because the selection experiments have been conducted for more than 27 generations, genetic variation may be eroded. Furthermore, because another previous study reported physiological costs to L-strains, the L-strains selected artificially for longer duration of death-feigning may have suffered more costs than the S-strains. In the present study, therefore, we relaxed the selection pressure after the 27th or 30th generation of S- and L-strains. We also carried out reverse selection during the most recent eight generations of S- and L-strains. The results showed that each strain clearly responded to relaxation of selection and reverse selection, suggesting that (1) additive genetic variation still existed in both strains after long-term selection, and (2) selection for shorter and longer duration of death-feigning was costly. These results suggest that anti-predator behavior is controlled by many loci, and longer or shorter duration of death-feigning is costly in a laboratory without predators.  相似文献   

17.
Three laboratory strains of Helicoverpa armigera (Hübner) were established by mating of field-collected insects with an existing insecticide-susceptible laboratory strain. These strains were cultured on artificial diet containing the Cry1Ac protoxin of Bacillus thuringiensis using three different protocols. When no response to selection was detected after 7-11 generations of selection, the three strains were combined by controlled mating to preserve genetic diversity. The composite strain (BX) was selected on the basis of growth rate on artificial diet containing Cry1Ac crystals. Resistance to Cry1Ac was first detected after 16 generations of continuous selection. The resistance ratio (RR) peaked approximately 300-fold at generation 21, after which it declined to oscillate between 57- and 111-fold. First-instar H. armigera from generation 25 (RR = 63) were able to complete their larval development on transgenic cotton expressing Cry1Ac and produce fertile adults. There appeared to be a fitness cost associated with resistance on cotton and on artificial diet. The BX strain was not resistant to the commercial Bt spray formulations DiPel and XenTari, which contain multiple insecticidal crystal proteins, but was resistant to the MVP formulation, which only contains Cry1Ac. The strain was also resistant to Cry1Ab but not to Cry2Aa or Cry2Ab. Toxin binding assays showed that the resistant insects lacked the high affinity binding site that was detected in early generations of the strain. Genetic analysis confirmed that resistance in the BX strain of H. armigera is incompletely recessive.  相似文献   

18.
Effects of inbreeding on the development and reproduction of the predatory pentatomid Podisus maculiventris were assessed throughout 30 generations following introduction in the laboratory. Developmental and reproductive fitness of two mildly inbred lines did not differ dramatically from that of a reference population. In most generations, egg weight, egg hatch and developmental rate of nymphs were greater in the reference strain than in both inbred strains, but fecundity and longevity did not differ among strains. In the 30th generation, fecundity of all strains had dropped to about half of that observed in the 15th generation, which was presumably related to non-genetic factors. There were consistent differences among strains for adult body weight and size, indicating heritable variation. A positive relationship between weight at day 14 and humeral width of P. maculiventris females was found, but neither of these parameters was associated with total fecundity. In the 30th generation, predators from both inbred lines had generally similar predation capacities to those from the reference population. No significant relationship could be detected between body weights and predation rates of either nymphs or adults. The use of inbreeding to minimize selective adaptation during rearing or to select for favourable traits in P. maculiventris is discussed.  相似文献   

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