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1.
不同温度条件下三角新小卷蛾实验种群生命表   总被引:1,自引:1,他引:0  
在 16、20、24、28 和 32 ℃5 个温度条件下,观察温度对三角新小卷蛾(Olethreutes leucaspis Meyrick)各虫态生长、发育及存活的影响,组建三角新小卷蛾实验种群生命表。结果表明,在 16~28 ℃条件下,三角新小卷蛾各虫态及世代生活历期随着温度的升高而缩短。卵期、幼虫期、蛹期、成虫期及世代的发育起点温度分别为 4.92、3.91、8.54、11.14 和 4.30 ℃,有效积温分别为 55.8、194.4、167.7、49.9 和 544.9 日度。卵孵化率都在92 %以上。内禀增长力(r m )均大于 0,种群趋势指数(I)均大于 1,在 16~32 ℃温度下该虫种群呈增长趋势。 三角新小卷蛾发育适宜温度为 24~28 ℃。  相似文献   

2.
在不同温度条件下(24、26、28、30、32℃),建立丽草蛉(Chrysopa formosa Brauer)实验种群生命表,研究温度对丽草蛉实验种群生长发育及繁殖的影响。结果表明:丽草蛉卵期、幼虫期、蛹期、产卵前期和世代发育起点温度和有效积温分别为9.22、7.47、8.69、7.04、7.52℃和72.40、302.21、240.86、140.49、793.16日度。丽草蛉各虫态发育历期随着温度的升高而缩短;丽草蛉发育速率与温度为显著相关性;内禀增长率(rm)均大于零,种群趋势指数(I)均大于1,丽草蛉实验种群呈增长状态;在26、28、30℃时,丽草蛉内禀增长率(rm)及种群趋势指数(I)分别为0.095 0、0.116 3、0.113 9及48.363 5、66.610 0、48.069 3。26~30℃为丽草蛉种群生长的适宜温度。  相似文献   

3.
为大豆田间大造桥虫发生危害的预测和防控提供依据。以大豆为寄主食料,研究了22、25、28、31、34℃共5个温度处理对大造桥虫各虫态的发育历期、发育速率、存活率和成虫繁殖的影响,测算了各虫态的有效积温。结果表明:在22~31℃范围内,各虫态发育历期均随温度升高而缩短,且卵、幼虫、预蛹及蛹期的发育速率与温度呈显著正相关;34℃高温对卵发育有明显抑制作用,1~5龄幼虫可以正常发育,但6龄幼虫无法存活;卵在22~28℃时孵化率均在98%以上,幼虫及蛹的存活率均在28℃时最高。大造桥虫卵、幼虫和预蛹的发育起点温度分别为6.68,9.10和10.97℃,有效积温分别为88.96,333.41和33.97日·度。成虫单雌产卵量在31℃时最高为754.83粒,28℃时次之为726.28粒。  相似文献   

4.
温度对芒果小爪螨实验种群增长的影响   总被引:3,自引:1,他引:2  
在16,20,24,28,32℃条件下观察芒果小爪螨的发育、存活及繁殖情况。结果表明:芒果小爪螨世代发育历期在32℃时最短,为9.20d,16℃时最长,为29.07d。卵、幼螨、若螨、产卵前期及世代的发育起点温度分别为8.77,9.37,10.61,11.13,8.91℃,有效积温分别为93.46,30.29,44.96,14.24,191.83日度,在16~32℃,芒果小爪螨发育的速率及雌螨寿命与温度呈直线相关。世代存活率在24℃时最高,为89.6%,32℃和16℃时,分别降至69.1%和55.8%。雌螨产卵量在28℃时最高,达40.14粒/雌,在32℃时最低,为8.44粒/雌。卵孵化率、幼螨、若螨及世代存活率、雌螨产卵量等随温度的上升而呈抛物线趋势。净增殖率(R0)、内禀增长率(rm)、周限增长率(λ)等种群特征参数以28℃时最高,分别为27.3342,0.3957,1.4854。平均世代历期和种群加倍时间分别以32℃和28℃时最短,分别为7.5186d,1.7517d。种群增长指数以24℃时最高,28℃时略低,分别为24.88和24.45。芒果小爪螨对温度较敏感,24~28℃为芒果小爪螨种群增长的最适温度。  相似文献   

5.
在20、24、28、32、36℃不同温度条件下,观察温度对新菠萝灰粉蚧[Dysmicoccus neobrevipes(Beardsley)]生长、发育和存活的影响。组建相应温度条件下新菠萝灰粉蚧实验种群生命表。实验结果表明,在20~32℃温度范围内,新菠萝灰粉蚧各虫态的发育历期随温度的升高而缩短。若虫期、产虫前期和世代历期的发育起点温度为9.47、11.36、10.61℃;有效积温为531.29、748.35、1128.72日度。种群趋势指数(I)均大于1,内禀增长力(rm)均大于0,新菠萝灰粉蚧种群呈增长趋势。该虫发育适宜温度为24~28℃。  相似文献   

6.
稻水象甲的生物学特性   总被引:2,自引:0,他引:2  
描述了稻水象甲(Lissorhortrus oryzophilus Kusche)各虫态的形态特征及各龄历期。通过室内饲养和野外观察,研究了该虫的生物学特性:在长沙地区1年发生1~2代,以成虫越冬,幼虫在25士1℃温度条件下,完成一个世代的历期为48.2d,卵期7d,幼虫期30d,蛹期10d,成虫期30d左右。试验证明,在一定温度范围内,随着温度的升高,发育历期明显缩短。发育最适温度在22℃~25℃之间,卵的孵化率为84.2%,幼虫成活率为87.5%。但在高温条件下(〈32℃时),卵的孵化率和幼虫成活率相当低,并随着发育龄期增加死亡率增高。  相似文献   

7.
芒果毒蛾生物学特性研究   总被引:1,自引:0,他引:1  
通过室内饲养观察,测定室温下芒果毒蛾的发育历期,各龄幼虫的体长,各龄幼虫头壳宽度,成虫性比,雌虫产卵量;测定不同温度下,芒果毒蛾各虫态的发育历期,发育起点温度和有效积温等特性,研究结果表明;芒果毒蛾的发育历期为65.5d,雌幼虫的体长变化为0.3-4.5cm,头壳宽度变化为0.72-4.58mm;雄幼虫的体长变化为0.3-3.46cm,头壳宽度变化为0.7-3.62mm;成虫雌雄比为1:1.5;雌虫产卵量为300粒左右,世代发育起点温度为12.73℃,有效积温为715.22日度。  相似文献   

8.
采用室内外观察法和最小二乘法研究胶刺蛾(Chalcocelis albigutataSnellen)的生物学特性。结果表明:胶刺蛾以幼虫危害油茶叶片,老熟幼虫在叶面处结茧化蛹,每年11月中旬至次年4月上旬以第4代蛹越冬;幼虫共5龄,在25℃下,该虫的世代历期为(89.8±2.3)d;成虫具有正趋性,雌虫平均寿命5.8 d,雄虫平均寿命4.3 d,平均每雌产卵117.5粒,林间性比为1.32∶1(♀∶♂);不同温度对胶刺蛾各虫态及世代的发育有极显著的影响(P〈0.01),且发育历期均随着温度的升高而降低;胶刺蛾的卵、幼虫、蛹的发育起点温度分别为7.17、7.07、6.26℃,有效积温分别为87.09、650.19、508.0日度,世代的发育起点温度为7.17℃,有效积温为1373.77日度。  相似文献   

9.
结合田间调查和采用室内逐日观察法,在6个温度20、25、28、32、36和40℃,湿度75%的条件下,以银合欢种子为食料,对银合欢豆象在不同温度下的各虫态发育历期进行了系统的观察和研究。结果表明,银合欢豆象卵期、幼虫及蛹期的发育起点温度分别为10.50、9.52和12.79℃。在20~40℃条件下,各虫态的发育速率与温度呈抛物线相关,低温和高温都不利于其生长发育。  相似文献   

10.
为探明温度对大豆主要害虫豆卷叶螟生长发育的影响,以大豆叶片为主要寄主饲料,研究了19,22,25,28,31℃共5个恒温处理对豆卷叶螟不同虫态的发育历期、发育速率和存活率的影响。结果表明:在19~31℃范围内,随着温度升高,各虫态的发育历期均缩短,发育速率与温度呈显著正相关。豆卷叶螟卵、幼虫、蛹、成虫和世代发育起点温度分别为9.89,10.90,11.18,19.57和13.49℃,有效积温依次为75.16,193.39,98.59,48.34和431.04 d·℃。豆卷叶螟种群存活曲线属于DeveyⅢ型,表现为卵期的高死亡率。这些结果为豆卷叶螟的预测预报提供了基础参考数据。  相似文献   

11.
Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future.  相似文献   

12.
Résumé Fusarium culmorum et, dans une moindre mesure,F. avenaceum, F. sambucinum, Colletotrichum coccodes etCylindrocarpon sp. ont été isolés de tubercules entreposés en atmosphère contr?lée (AC) et atteints de pourriture grave. Des expériences d'inoculation de tubercules avec 10 espèces ou variétés fongiques et conservation en AC à 8 et 10°C ont montré que: 1) les champignons non pathogènes en atmosphère normale (ex.:Cylindrocarpon sp.) le devenaient en AC, 2) ceux qui étaient faiblement pathogènes en atmosphère normale étaient nettement plus virulents en AC (ex.:F. culmorum), 3) les espèces ou variétés virulentes en conditions d'air normales (Fusarium sulphureum etPhoma exigua var.foveata) ne provoquaient pas de pourriture plus grave en AC et leur activité pouvait même être légérement freinée.
Summary The extensive rotting of tubers which occurred during storage trials in controlled atmospheres has led to a mycological and pathological study of the rots. The most frequently isolated species wasFusarium culmorum althoughF. avenaceum, F. Sambucinum, Coletotrichum coccodes and aCylindrocarpon sp. were also present. Tubers of cvs Bintje and Ulla were inoculated with 19 isolates of 10 fungal species or varieties associated with rotting of stored tubers (Table 1). The tubers were incubated at 8 or 10°C in normal or controlled (2% O2:1% CO2, 2% O2:6% CO2, 2% O2:12% CO2, 6% O2:6% CO2) atmospheres and the extent of rotting was determined a month later (Tables 2 and 3 and Fig. 2). Species which were weakly virulent in a normal atmosphere (variousFusarium spp. andPhoma exigua var.exigua) were clearly more aggressive in the controlled atmosphere and this was especially evident in the case ofF. culmorum. Species ot pathogenic in a normal atmosphere under experimental conditions (Colletotrichum coccodes, Cylindrocarpon sp.,Phoma eupyrena) caused rotting in the controlled atmosphere. The two species which were virulent in a normal atmosphere (F. sulphureum andP. exigua var.foveata) were also virulent in the controlled atmosphere and in some cases the extent of rotting was even less. As a general rule, rotting caused by weakly virulent fungi was greater in both cultivars in the controlled than in a normal atmosphere.

Zusammenfassung Eine starke F?ulnis von in Kontrotrollierter Atmosph?re gelagerten Kartoffelknollen veranlasste eine mykologische und pathologische Untersuchung. Der am h?ufigsten isolierte Pilz warFusarium culmorum. F. avenaceum, F. sambucinum, Colletotrichum coccodes undCylindrocarpon sp. wurden ebenfalls bestimmt. Neunzehn St?mme von 10 Pilzsorten oder-Arten welche bei Lagerf?ulnis vorkommen (Tab. 1) wurden auf Knollen der Sorten Bintje und Ulla inokuliert. Die Lagerung wurde bei 8 oder 10°C under Normalbedingungen oder kontrollierter Atmosph?re durchgeführt (2% O2:1% CO2, 2% O2:6% CO2, 2% O2:12% CO2, 6% O2:6% CO2). Der F?ulnisgrad (Abb. 1) wurde nach einem Monat bonitiert. Die Ergebnisse sind in den Tabellen 2 und 3 dargestellt und in der Abb. 2 illustriert. Unter in Normalbedingungen nur schwach virulente Arten (verschiedeneFusarien undPhoma exigua var. exigua) waren deutlich aktiver in kontrollierter Atmosph?re. Dies was besonders der Fall fürF. culmorum. Pilze, die im Versuch unter Normalbedingungen nicht pathogen waren (Colletotrichum coccodes, Cylindrocarpon sp., Phoma eupyrena), haben unter kontrollierter Atmosph?re Sch?den verursacht. Hingegen werden die beiden unter Normalbedingungen sehr pathogenen Arten (F. sulphureum undP., exigua var.foveata), durch kontrollierte Atmosph?re wenig beeinflusst. Es wurde sogar in einigen F?llen eine gewisse Verringerung des F?ulnisbefalls beobachtet. Ganz allgemein haben die getesteten kontrollierten Bedingungen die Entwicklung der Pilzf?ulnis an beiden Kartoffelsorten gef?rdert, speziell durch Pilzarten, welche unter Normal-bedingungen wenig Sch?den verursachen.
  相似文献   

13.
The review of the 2016–2017 marine pharmacology literature was prepared in a manner similar as the 10 prior reviews of this series. Preclinical marine pharmacology research during 2016–2017 assessed 313 marine compounds with novel pharmacology reported by a growing number of investigators from 54 countries. The peer-reviewed literature reported antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral activities for 123 marine natural products, 111 marine compounds with antidiabetic and anti-inflammatory activities as well as affecting the immune and nervous system, while in contrast 79 marine compounds displayed miscellaneous mechanisms of action which upon further investigation may contribute to several pharmacological classes. Therefore, in 2016–2017, the preclinical marine natural product pharmacology pipeline generated both novel pharmacology as well as potentially new lead compounds for the growing clinical marine pharmaceutical pipeline, and thus sustained with its contributions the global research for novel and effective therapeutic strategies for multiple disease categories.  相似文献   

14.
SUMMARY

Vitamin A, iodine, and iron deficiencies affect large numbers of people worldwide. A deficiency of one or more of these micronutrients adversely affects the physical and mental abilities of humans. South Asia contains a high percentage of these individuals, not just because of its large population, but also the prevalence of deficiency is higher there than in many other parts of the world. The reasons for the high rates of deficiency in South Asia are many, but they include inadequate availability of micronutrient-rich foods, sub-optimal dietary habits, and high rates of infection. Across the region, national plans vary from (a) increasing availability of appropriate foods, (b) introducing new dietary behaviors, (c) improving health status, and (d) directly addressing deficiency through intervention programs. The extent to which each of the countries is making progress toward the goals of these plans can help in understanding the priorities for future efforts to address micronutrient malnutrition. This article discusses the adverse effects of micronutrient deficiencies in humans with special reference to South Asia.  相似文献   

15.
Summary

Within the last three decades, the rice-wheat cropping system has triggered, and with time, aggravated soil micronutrient deficiencies in the Indo-Gangetic Plains (IGP). This has largely been due to the shift from an earlier rice and wheat monoculture with low yielding, long duration indigenous varieties, to an intensive rice-wheat rotation cropping system with short duration modern high yielding varieties on the same piece of land. The problems related to micronutrient deficiency in the IGP are more due to the size of its available pools in the soil rather than its total contents and are greatly influenced by crop management, or rather its mismanagement. Deficiency of zinc is widespread in the IGP, but with the extensive use of zinc sulfate, zinc deficiency has reduced in some areas of the region. Meanwhile, the deficiency of Fe, Mn and B has increased in the IGP. Deficiency of Cu and Mo is location specific and can limit rice and wheat yields. The adoption and spread of the rice-wheat system in permeable coarse textured soils, particularly in the western IGP, not only caused iron deficiency in rice but also resulted in the emergence of manganese deficiency in wheat. In highly calcareous and acidic soils, boron is the next limiting micronutrient in crop production after zinc. Bumper rice and wheat harvests in the past decade, the declining use of organic manures in the region and except for the widespread use of zinc sulfate, a general lack of awareness amongst farmers on micronutrient deficiency problems has contributed to micronutrients limiting rice and wheat yields in the IGP. Approaches to alleviating micronutrient deficiencies include matching the crop removals of the micronutrients with its replenishments through their respective external carriers, supplementation through organic sources and mobilization/utilization through cultivation of micronutrient efficient crop cultivars. Identification of efficient micronutrient carriers and finding the optimum rate, mode and time of its application is important in ameliorating the micronutrient deficiencies. This article reviews the extent of micronutrient deficiency and discusses various management options available to reduce micronutrient deficiency induced crop yield reduction for rice and wheat in the Indo-Gangetic Plains.  相似文献   

16.
Plains rough fescue ( F estuca hallii) is an important forage grass species in western Canada. Seed for use in pastures and ecological restoration is in high demand but supply is limited because F. hallii is an erratic seed producer. Seed producers require an understanding of the factors that influence flowering and seed set in this species. The aim of this study was to assess the effect of irrigation and nitrogen fertilization on the flowering and growth of F. hallii in a native rough fescue prairie in Alberta, Canada. Irrigation had a strong positive effect on seedhead density, whereas fertilization had limited effects on growth and reproduction of F. hallii. These results demonstrate that under field conditions, available moisture is likely to be a key factor driving flowering and seed production in F. hallii.  相似文献   

17.
Marine biomass diversity is a tremendous source of potential anticancer compounds. Several natural marine products have been described to restore tumor cell sensitivity to TNF-related apoptosis inducing ligand (TRAIL)-induced cell death. TRAIL is involved during tumor immune surveillance. Its selectivity for cancer cells has attracted much attention in oncology. This review aims at discussing the main mechanisms by which TRAIL signaling is regulated and presenting how marine bioactive compounds have been found, so far, to overcome TRAIL resistance in tumor cells.  相似文献   

18.
Summary Morphological and biochemical parameters that could be involved in resistance to late blight were studied in non-infected and in infected potato hybrids resulting from a cross betweenSolanum phureja, resistant toPhytophthora infestans, and a susceptibleSolanum tuberosum. Some morphological differences between resistant and susceptible hybrids, indicating a positive correlation between stem diameter and phloem thickness in the stem and resistance toP. infestans, were observed. The lignin content in the leaves of the resistant hybrid rose upon infection byP. infestans. In the leaves of the susceptible hybrid, a diminution of the lignin content could be observed upon infection byP. infestans. In the same context, peroxidasic activity raised upon infection byP. infestans in both resistant and susceptible hybrids. Further characterization of the hybrid clones based on the polymorphism of peroxidases was attempted using isoelectric focusing.  相似文献   

19.
Potato is an important crop, grown worldwide. It suffers from many pests and diseases among which late blight, caused by the oomycete Phytophthora infestans, is the worst. The disease is still causing major damage in many potato production areas and control is only possible by applying fungicides frequently. The knowledge on the molecular biology and genetics of the interaction between the plant and the oomycete is developing rapidly. These are relevant fields of study, currently dominated by the discovery of many resistance genes and numerous effector proteins and the analysis of their specific mode of action. These studies may yield essential information needed for the development of durable resistance. The long-term and worldwide effort to breed for resistance so far has had little effect. A novel breeding approach may change this. It is based on cisgenic modification (CM) consisting of marker-free pyramiding of several resistance genes and their spatial and temporal deployment yielding dynamic varieties that contain potato genes only. It is envisioned that this CM approach with potato’s own genes will not only prove societally acceptable but may also result in simplifications in the legislation on use of the CM approach. Various parties in the potato research arena intend to cooperate in this novel approach in a number of developing countries where potato substantially contributes to food security. The use of resources such as land, water and energy improves when the effect of late blight is markedly reduced.  相似文献   

20.
In an experimental breeding scheme to improve late blight (Phytophthora infestans) and white potato cyst nematode (Globodera pallida) resistance of tetraploid potato over three generations of crossing and selection, 15 clones survived the final selection, and these were derived from 15 great-grandparents. There was no direct selection for resistance to Potato virus Y (PVY), but 14 out of the 15 great-grandparents were resistant to PVY and three had extreme resistance. Thirteen of the 15 descendants had PVY resistance and one extreme resistance. This was within the range expected for a random (unselected) sample from the genotypes of the great-grandparents. Hence, we found no evidence for any positive or negative association between PVY resistance and the attributes selected. The conclusion is that laborious selection is not required in every generation when many parents have PVY resistance, including some with more than one copy of a PVY resistance gene or resistance at more than one locus. However, in the future, determining the major virus resistance genes present in potential parents in each generation using diagnostic molecular markers would prevent susceptible × susceptible crosses being made and maximise the number of resistant × resistant ones.  相似文献   

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