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1.
斜纹夜蛾核多角体病流行的时间动态   总被引:5,自引:0,他引:5  
通过对病病幼虫进行跟踪观察,观察了病毒不同浓度处理下,斜纹夜蛾核多角体病的田间流行动态结果表明,在试验病毒浓度范围(3.1*10^5-3.1^10^8PIBs.ml^-1)内,幼虫大多在喷施病毒后第4天开始发病,第5-7天为发病高峰,第5-6天开始病死,第6-天为病死高峰,宿主现患高峰民发病高峰基本一致。宿主种群发病和病死时间分布可用时间-剂量-死亡率模型较好地拟合,模型模拟与实测值有较好的吻合(  相似文献   

2.
通过荧光光谱法研究了稀土Ce^3+与二棕榈酰磷脂酰胆碱(DPPC)脂质体的相互作用,结果表明,Ce^3+-DPPC体系的激发波长在247nm,294nm,发射波长在344nm,与水合Ce^3+的荧光光谱完全不同。这表明Ce^3+与DPPC形成了复合物,该复合物的荧光光谱同Ce^3+-DHP复合物的荧光光谱一致,可以认为Ce^3+与DPPC分子上的磷酸基团相作用。  相似文献   

3.
经6%-12%Dextran T70密度梯度离心,获得了纯度较高的7d龄花生幼苗下胚轴质膜和液泡膜制剂。150mmol/L NaCl或10℃低温处理花生幼苗24h,其下胚轴质膜上的Mg^2+激活的ATPase活性分别提高了37.6%和17.2%;Ca^2+-ATPase活性分别提高45.8%和33.6%。上述盐或低温处理也提高了液泡膜上Mg^2+激活的ATPase活性,分别为对照的141.2%和1  相似文献   

4.
玫瑰花红色素及其稳定性研究   总被引:28,自引:0,他引:28  
以玫瑰花色素作为新型天然食用色素的可行性进行了初步研究。对光、温度、pH值、氧化介质、还原介质、蔗糖、咸味(NaCl)、铝制品(FeCl3)、铜制品(CuCl2)、锡制品(SnCl2)等对色素的稳定性影响,进行了初步探讨。结果表明,该色素对光、热耐受性好;适用pH值范围宽;耐氧化性较差,耐还原性较好;Fe^3+和Sn^2+对其吸光值有明显影响,Cu^2+、Al^3+、食盐和蔗糖则影响甚微。  相似文献   

5.
脱金属硫蛋白与镉离子的络合作用及构象研究   总被引:1,自引:0,他引:1  
用圆二色(CD)谱地研究兔肝脱金属硫属蛋白的两个亚型与Cd^2+的络合作用及对重组MT构象的影响。观测了apo-MT垢巯基在空气和室温下的稳定性。在PH4.71,镉重组MT1的CD谱特征峰在257nm(+),238nm(-),226nm(+)与镉诱导的天然MT1相同。在空气存在和PH7.90的CD谱只有243nm(+)一个峰。向两亚型分别加入7eqCd^2+测定CD谱随PH值的变化,发现在PH2.  相似文献   

6.
镧对烟草愈伤组织和油菜幼根钙含量的影响   总被引:10,自引:1,他引:9  
MS培养基中添加镧(La)(0 .01 ~0 .10m mol·L- 1) 培养烟草愈伤组织,其总Ca2 + 及原生质体Ca2 + 含量明显比对照( 不加La) 低;长时间( 继代培养30d) 较短时间培养( 悬浮培养24h) 低.低浓度(0 .01 ~0 .051mol·L- 1)La3 + 使细胞壁中Ca2 + 含量高于对照并随浓度提高而增加,高浓度(0 .101mol·L- 1) 则减少.与Ce2 + 相比较,La3 + 的排Ca2 + 作用稍弱于Ce3 + .以不同浓度La(NO3)3 溶液浸种,油菜幼根总Ca2 + 及原生质体中Ca2 + 含量变化与上述类似.La3 + 使烟草愈伤组织褐化明显,生长量比对照低.  相似文献   

7.
用激光散射技术结合浊点法测定了加有不同离子强度的四种三价稀土盐(LaCl3,CeCl3,La(NO3)3,Ce(NO3)3)的C8-卵磷脂溶液的液-液相分离曲线,从中得出了相分离临界温度(Tc)和临界浓度(Xc)随盐类型和盐离子强度变化曲线。发现各种三价盐都使Tc和Xc随离子强度的增加先降低,然后再使之升高。其变化也遵循我们导出的式子:TC=TC0+A1I12-A2I所描述的规律。各种正、负离子对Tc和Xc的相对作用程度分别为:Ce3+>La3+;NO3->Cl-。用液-液相分离曲线的实验数据,根据吉布斯自由能模型,还计算了胶团的作用因子C和形成因子Δμ.借助这两个表象参数,利用加盐表面活性物胶团溶液的唯象理论,从理论上算出了各两相共存曲线,其结果与实验值的吻合令人满意。  相似文献   

8.
渗透胁迫下稻苗中铁催化的膜脂过氧化作   总被引:26,自引:1,他引:25  
在-0.7MPa渗透胁迫下,水和思苗体内O2↑-.和H2O2大量产生,Fe^2+含量与膜脂过氧化产物MDA含量呈极显著的正相关。外源Fe^2+、Fe^3+、H2O2、Fe^2++H2O2、DDTC均能刺激膜脂过氧化作用,而铁离子的螯合剂DTPA则有缓解作用。OH的清除剂苯甲酸钠和甘露醇能明显地抑制渗透胁迫下Fe^2+催化的膜脂过氧化作用。这都表明渗透胁迫下水稻幼苗体内铁诱导的膜脂过氧化作用主要是由  相似文献   

9.
温度对红点唇瓢虫实验种群的影响   总被引:4,自引:0,他引:4  
在7种温度下测定了红点唇瓢虫(Chilocorus kuwanae Silvestri)发育速率,并求得各虫态的发育起点温度和有效积温。其发育速率与温度的关系能很好地用王如松等(1982)提出的模型进行拟合。由此模型估计出最低、最高临界温度和最适发育温度,分别为10.42-13.01-℃、℃33.53-37.03℃和24.99-30.12℃。卵期忍耐温度变化的能力最强。4龄幼虫最弱。温度明显地影响  相似文献   

10.
.OH在博莱霉素A5介导的DNA断链反应中的作用   总被引:4,自引:0,他引:4  
利用ESR技术研究了博莱霉素A5(BLMA5)、Fe^2+,O2体系中.OH的产生。并用TBA反应检测了该系对DNA的断链作用。以Fe^3+,Cu^+或Cu^2+替换Fe^2+,则体系中无.OH产生,同时也失去对DNA的断链作用;一定浓匠.OH清除剂可完全清除.OH,地对DNA断链影响甚微;还原剂可淬灭体系中的.OH,却能促进DNA的断链反应;SOD可清除体系中的.OH,失活的SOD夫此功能,但两  相似文献   

11.
嗜卷书虱实验种群生命表的研究   总被引:11,自引:3,他引:8  
在不同温度和湿度条件下对嗜卷书虱进行饲养,分别组建春实验种群特定年龄和特定时间生命表,并应用Morris模式及SWeibull频数分布以探讨温、湿度与嗜卷书虱种群数量变动的关系。结果表明,温、湿度对存活率的作用是影响该实验种群趋势指数(I)值最重要的因子,在适宜温、湿度条件下,种群存活曲线属DeeveyⅠ型,而在不太适宜条件下则属DeeveyⅢ型,理论上30.63℃时周限增长率(λ)最大,达1.0628倍/天,该虫发育和繁殖的最适温区为28-30℃,最适相对湿度在80%左右。  相似文献   

12.
松毛虫狭颊寄蝇实验种群生态学研究   总被引:2,自引:2,他引:0  
松毛虫狭颊寄蝇(Carcelia matsukarehae)是松毛虫重要的寄生天敌之一。在控制松毛虫自然种群增长中起重要的作用。本文在15℃、18℃、22℃、25℃、29℃、32℃6个恒温。相对湿度为70%~85%,光照为12:12(L:D)的条件下研究了松毛虫狭颊寄蝇的生态学特性。结果表明,松毛虫狭颊寄蝇的世代发育起点温度是5.23℃。积温为523.73日·度。成虫寿命在没有补充营养的条件下为1.3~8.06d,喂以30%蜜糖水。寿命可以从9.63d延长到36.42d。成虫产卵的最适温度为236℃,每雌最大产量为86粒.种群增长最适温度22~25℃.以近似方法计算22℃和25℃下实验种群繁殖特征生命表参数。在22℃,R0、T0、rc和A值分别为24.89、37.33、0.086和1.089。在25℃时分别为20.01、32.38、0.09和1.10.22℃时种群最大LxMx出现在成虫羽化后第33~38天。25℃时的LxMx最大值出现在成虫羽化后第29~34天。  相似文献   

13.
Necremnus artynes is native to the Mediterranean region where it has been observed in greenhouses parasitising Tuta absoluta on tomato. In this study, we evaluated the suitability of the different instars of T. absoluta as hosts for N. artynes and the life-history traits of N. artynes at three different temperature regimes (20, 25 and 30°C) on third instar T. absoluta larvae infesting tomato. N. artynes females preferred third instar T. absoluta larvae for oviposition, whereas host-feeding was significantly higher on the second instar larvae. Duration of life stages was no different between sexes but was affected by temperature, being significantly reduced as temperature increased. Pre-imaginal survival also decreased with temperature and the percentage of females was ca. 70% under all temperature regimes. Adult longevity was 1.5-fold significantly greater at 25°C compared to 30°C with no differences between 20 and 25°C. Fecundity was estimated at 36.3±7.80, 51.8±10.65 and 52.1±10.03 eggs/female and host-feeding at 59.5±8.50, 71.6±12.07, 51.4±7.89 hosts/female at 20, 25 and 30°C, respectively, although these differences among temperatures were not significant. However, oviposition and feeding rate were significantly higher at 30 and 20°C, respectively. The estimated intrinsic rate of increase (r m) was significantly higher as temperature increased from 20 to 30°C and it was greater than those reported for T. absoluta on tomato, indicating the potential of N. artynes to control this pest.  相似文献   

14.
15.
Abstract:  We determined the influence of temperature on post-diapause development of overwintered Thecodiplosis japonensis Uchida et Inouye (Dipt., Cecidomyiidae) under various treatments (12, 15, 18, 21, 24, 27 and 30°C) in an effort to predict its spring emergence. Survival and developmental period for the overwintered larvae and pupae were significantly influenced by temperature. Linear and nonlinear regression models quantitatively described temperature-dependent development and survival of T. japonensis . The survival models exhibited right-skewed bell shape patterns for all stages, indicating a more detrimental impact on survival at high temperatures. Theoretical optimum temperatures with highest survival were 22.3, 24.0 and 24.0°C for the overwintered larvae, pupae and total post-diapause development (the larvae to adults) respectively. Pupal mortality was higher at all temperatures than larval mortality and the suitable range of temperature for pupae was narrower than that of larvae. The nonlinear Briere model estimated that optimum temperatures with the fastest development were 29.1°C for larvae, 27.6°C for pupae and 27.0°C for larvae to adults. In a linear model, the lower threshold temperatures were 5.1, 7.1 and 5.9°C for larvae, pupae, and larvae to adults respectively. A predictive degree-day model was developed using trap catches of T. japonensis adult emergence during 1991–1995. The model accounted for 84.6% of year-to-year variation in adult emergence and predicted accurately the median emergence time in 1996.  相似文献   

16.
The effect of temperature on egg development of the apple sawfly Hoplocampa testudinea Klug was studied under controlled conditions. Based on a linear model describing the relationship between temperature and developmental rates a thermal threshold of 6.9 °C and a thermal constant of 85 day-degrees were established. The experimental results were used to expand and parameterise an existing phenology model to include egg development and hatching of first instar larvae. The model thus became a valuable forecasting tool not only for adult emergence and the optimal monitoring period but also for egg hatch and the best timing of control measures against first instar larvae. The model was validated by comparing predictions with independent observations on egg-laying and subsequent hatching of first instar larvae under semi-field conditions.  相似文献   

17.
在15、19、22、25、28、31和35℃及RH80%的组合条件下,测定了菊小长管蚜的发育起点温度及有效积温,分析了温度与菊小长管蚜发育速率的关系.结果表明,菊小长管蚜各龄若虫的发育时间随温度的增加而缩短,4龄若虫的发育历时最长,平均为前三龄若虫历期的1.4倍.模拟分析表明,菊小长管蚜发育速率随温度的升高而加快,2、3龄若虫较1、4龄若虫对极端温度的忍耐性强,发育最适温度高.2、3龄若虫的极端温度忍耐值δ为6.70,最适发育温度为21.76℃,最高发育温度为40.97℃;1、4龄若虫极端温度忍耐值δ分别为4.70和4.50,最适发育温度分别23.76℃和22.49℃,最高发育温度为39.97℃和40.56℃;龄期越高,发育起点温度相对较低,发育所需的有效积温则越高.1~4龄若蚜的发育起点温度分别为6.93、5.02、4.58和4.46℃,有效积温分别为26.88、33.41、33.63和48.49℃·d^-1。  相似文献   

18.
Laboratory studies were conducted to assess the effect of temperature on the survival, development, fecundity, and longevity of Helicoverpa armigera (Hübner) at 11 constant temperatures ranging from 12.5 to 40 degrees C, as well as at five alternating temperature regimes (25-10, 30-15, 32.5-17.5, 35-20, and 35-27.5 degrees C) and under a photoperiod of 16:8 (L:D) h. H. armigera reared at constant temperatures did not develop from egg to adult (emergence) outside the temperature range of 17.5-32.5 degrees C. The alternating conditions expanded this range from 10 to 35 degrees C. The lowest developmental thresholds of the immature stages were estimated by a linear model and ranged from 10.17 (pupal stage) to 11.95 degrees C (egg stage) at constant temperature regimes and from 1.1 to 5.5 degrees C, respectively at alternating temperatures. The values of developmental thresholds estimated using the nonlinear (Lactin-2) model were lower than those estimated by the linear model for constant and alternating temperature regimes except for larval and pupal stages at constant temperatures. Mean adult longevity fluctuated from 34.4 d at 15 degrees C to 7.6 d at 35 degrees C. Females reared under all alternating temperature regimes laid more eggs than females reared at any, except the 25 degrees C, constant temperature treatment. The intrinsic rate of increase was highest at 27.5 degrees C, at both the constant and the corresponding alternating temperature regimes (0.147 and 0.139, respectively). Extreme temperatures had a negative effect on life table parameters.  相似文献   

19.
Inoda T 《Zoological science》2003,20(3):377-382
Mating season and embryonic development of the predaceous diving beetles, Dytiscus sharpi, (Coleoptera; Dytiscidae) were observed under artificial breeding conditions. Female and male adult insects started mating from November to March and gave first instar larvae mainly in April. When the mating was artificially delayed until February, first instar larvae appeared from the end of March to the middle of May. I also investigated the effects of temperature on larval development. Apparent hatchability of eggs was not affected by high temperature, however, their normal development after hatching was significantly interfered. Most of the first instar larvae kept at 20-25 degrees C from before hatching died within one day after hatching. By contrast, juveniles kept outdoors (7.0-20.9 degrees C) could develop at least until second instar larvae. Temperature >23 degrees C after hatching had no effects on larval development. From these observations, it was concluded that the reproduction strategy of Dytiscus sharpi, i.e. mating in late autumn and hatching in early spring would be the reasonable results of adaptation to the warm habitats where they are collected.  相似文献   

20.
Development times and survivorship of immature shore flies and longevity and reproduction of adult shore flies, Scatella tenuicosta Collin, reared on algae-infested filter paper, were studied at three temperatures (constant 20, 26, and 28.5 degrees C) through life table analysis. The development time for each individual life stage and the total time from egg to adult decreased with increasing temperature. Duration of the third (ultimate) larval instar ranged from 3.3 +/- 0.09 d at 20 degrees C to 1.4 +/- 0.04 d at 28.5 degrees C and was 1.7-1.9 times longer than the approximately equal first and second instars. Development of male and female shore flies from egg to adult needed an average of 14.5 +/- 0.13, 8.2 +/- 0.05, and 7.0 +/- 0.04 d at 20, 26, and 28.5 degrees C, respectively, and needed an estimated 154.4 +/- 1.2 thermal units (degree days). At these respective temperatures, adult females lived 21.8 +/- 2.2, 19.9 +/- 2.4, and 15.0 +/- 1.4 d and produced 379 +/- 62, 710 +/- 119, and 477 +/- 83 eggs during oviposition periods of 14.3 +/- 2.1, 15.0 +/- 2.2, and 10.8 +/- 1.4 d; daily lifetime egg production averaged 16.3 +/- 2.3, 33.5 +/- 3.8, and 29.7 +/- 3.5. Developmental stage-specific mortality was relatively low for all life stages at all temperatures, with maximum percent mortalities of 5.7% occurring in both the egg stage and in the third instar. The highest net reproductive rate (R(o)) was obtained for insects reared at 26 degrees C and was 329.6. The intrinsic rate of natural increase (r(m)) was highest at 28.5 degrees C and was 0.430. Generation time and doubling time of the population were shortest at 28.5 degrees C and were 12.4 and 1.6 d, respectively. Results suggested that 26 degrees C was near optimum for reproduction.  相似文献   

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