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1.
《农业工程》2013,33(3):172-177
Under the global warming conditions, great attention has been paid to the effects of precipitation on ecophysiological characteristics in desert plants. Nitraria tangutorum is one of the dominant shrubs distributes in desert outside Minqin oasis, Gansu Province. The artificial simulated rainfall experiments were carried out in four consecutive years from 2008 to 2011, in an attempt to understand the mechanisms of the photosynthetic response in desert plant to the variation of future precipitation pattern. The water and photosynthetic physiological characteristics of leaves in N. tangutorum were examined from July 24 to 26 in 2011 under different simulated rainfall increase gradients (increased 0%, 25%, 50%, 75% and 100% of mean annual precipitation, respectively). We measured leaf traits that could reflect both leaf water status (e.g., leaf water content and leaf water potential) and photosynthetic physiology (e.g., maximum net photosynthetic rate). The results showed that leaf water content and leaf water potential of N. tangutorum increased with increasing rainfall. Leaf water content and leaf water potential of N. tangutorum in the 100% increased rainfall treatment were significantly greater by 8.51% and 12.07% than the control (0% increased rainfall treatment). But leaf dry matter content and specific leaf weight gradually decreased with increasing rainfall. Leaf dry matter content and specific leaf weight in the 100% increased rainfall treatment were significantly lower by 6.92% and 25.93% than the control. Leaf maximum net photosynthetic rate (Amax), apparent quantum yield (AQY) and light saturation point (LSP) increased with increasing rainfall, while light compensation point (LCP) gradually decreased with increasing rainfall. AQY in the 100% increased rainfall treatment was significantly greater by 70.00% than the control. However, there were no significant differences in LSP and LCP between different treatments. Amax, transpiration rate (Tr), stomatal conductance (Gs) in the 100% increased rainfall treatment were significantly greater by 81.91%, 166.07% and 110.47% than the control, respectively. On the contrary, water use efficiency (WUE) in the 100% increased rainfall treatment was significantly less 48.28% than the control. There were no significant differences in intercellular CO2 concentration (Ci) and stomatal limitation value (Ls) between different treatments. The correlation analysis showed that there were significantly positive correlations between leaf water content, leaf water potential, Tr and Gs. However, there were significantly negative correlations between leaf dry matter content, leaf specific mass and Tr, Gs, leaf water content and leaf water potential, suggesting that leaf gas exchanges were regulated by leaf water status. Therefore, N. tangutorum could adapt to the tendency of future increasing precipitation by the coordination of water physiology and photosynthesis.  相似文献   

2.
不同生态稻区覆膜旱作稻氮营养生理及抗逆生理特性探讨   总被引:4,自引:0,他引:4  
不同生态稻区生态环境和栽培管理方式不同,覆膜旱作稻氮营养生理和抗逆生理与常规水作稻有些异同,尤其是体内NO3--N和NH4+-N含量及分布差异很大.杭嘉湖平原区覆膜旱作稻生长前期受干热天气影响,其分蘖期、拔节期、孕穗期体内NO3--N含量较水作稻有不同程度的降低,而NH4+-N含量则极显著提高;金衢盆地覆膜旱作稻孕穗期体内NO3--N含量比常规水作稻高,根部NH4+-N含量则显著降低,茎基部和叶片NH4+-N含量有一定增加.正常气候条件下两生态稻区覆膜旱作稻孕穗期叶片硝酸还原酶(NR)活性和谷氨酰胺合成酶(GS)活性较水作稻均有不同程度的提高;丙二醛(MDA)、可溶性糖及脯氨酸(Pro)含量与水作稻相差不大,表明不同生态稻区的覆膜旱作稻可以通过不同的栽培管理模式,促进生长发育,达到高产目的.  相似文献   

3.
木麻黄逆境生理研究进展(综述)   总被引:2,自引:0,他引:2  
本文综述水分、盐分、重金属和酸雨等逆境条件对木麻黄生长发育及生理生化等方面的影响,指出木麻黄造林的主要逆境因素是水分和盐分,并对今后的研究工作提出建议。  相似文献   

4.
武夷山不同海拔高度土壤有机碳矿化速率的比较   总被引:6,自引:0,他引:6  
应用土壤培养法,比较分析了武夷山不同海拔高度土壤在25℃和60%田间饱和含水量条件下培养110 d有机碳矿化速率和矿化率的差异.结果表明:不同海拔高度土壤有机碳矿化速率随海拔高度的升高而加快,高山草甸(0.08 g CO2-C·kg-1·d-1)分别比亚高山矮林、针叶林、常绿阔叶林快14.3%、60.0%和166.7%,差异主要存在于0~10 cm.土壤碳矿化率以针叶林最高(16.6%),分别比亚高山矮林、常绿阔叶林、高山草甸高37.0%、67.6%和79.1%.土壤有机碳矿化速率和矿化率均随土层加深而递减,递减的幅度在不同海拔高度土壤间存在显著差异(P<0.05).研究结果揭示,土壤碳矿化速率和矿化比率随着海拔高度的变化而产生显著的变化.  相似文献   

5.
Food availability in the environment is often low and variable, constraining organisms in their resource allocation to different life‐history traits. For example, variation in food availability is likely to induce condition‐dependent investment in reproduction. Further, diet has been shown to affect ejaculate size, composition and quality. How these effects translate into male reproductive success or change male mating behavior is still largely unknown. Here, we concentrated on the effect of meal size on ejaculate production, male reproductive success and mating behavior in the common bedbug Cimex lectularius. We analyzed the production of sperm and seminal fluid within three different feeding regimes in six different populations. Males receiving large meals produced significantly more sperm and seminal fluid than males receiving small meals or no meals at all. While such condition‐dependent ejaculate production did not affect the number of offspring produced after a single mating, food‐restricted males could perform significantly fewer matings than fully fed males. Therefore, in a multiple mating context food‐restricted males paid a fitness cost and might have to adjust their mating strategy according to the ejaculate available to them. Our results indicate that meal size has no direct effect on ejaculate quality, but food availability forces a condition‐dependent mating rate on males. Environmental variation translating into variation in male reproductive traits reveals that natural selection can interact with sexual selection and shape reproductive traits. As males can modulate their ejaculate size depending on the mating situation, future studies are needed to elucidate whether environmental variation affecting the amount of ejaculate available might induce different mating strategies.  相似文献   

6.
反义寡聚核苷酸:生理学研究中的新工具   总被引:4,自引:0,他引:4  
唐宗湘  李葆明 《生命科学》1999,11(4):180-183
反义寡聚核苷酸(antisenseoligonucleotide,AS-ON)通常是指与体内某RNA或DNA序列具有互补顺序,并能通过碱基配对与互补链杂交,从而影响其转录或翻译过程的核酸片段。AS-ONs技术的近来应用为生理学研究开辟了一条新路,对将来了解基因的功能提供了一种新手段。本文综述了AS-ONs的设计策略、作用机理、修饰和导入方式等基本问题,旨在对AS-ONs的应用提供参考。  相似文献   

7.
The biochemical composition of larvae of Teredo navalis L. and Bankia gouldi (Bartsch) (Bivalvia: Teredinidae) was examined throughout larval development at 23°C and 30–32%. salinity in the presence of the phytoplankton food Isochrysis aff. galbana (clone T-ISO), during a delay of metamorphosis in the presence of food but absence of a wood substratum and during periods of enforced starvation. Newly released Teredo navalis larvae had a mean length (L) and height (H) of 89.3 and 76.1 μm respectively. The first appearance of pediveliger larvae at 212.1 μm L and 230.0 μm H occurred 27 days after release. Larval dry weight increased from 0.29 μg to 1.96 μg during this period. Newly formed straight hinge larvae of Bankiagouldi had dimensions of 62.8 μm L and 49.8 μm H. Metamorphically competent B. gouldi larvae had dimensions of 230.0 μm L and 282.9 μm H and were first observed 20 days after fertilization. Larval dry weight increased from 0.06 μg to 2.20 μg during this period. During enforced delay of metamorphosis the ash-free dry weight of Teredo navalis larvae decreased whereas the ash free dry weight of Bankia gouldi larvae increased. During the early period of shelled larval development both species showed similar decreases in lipid, protein and carbohydrate levels (μg·mg dry weight?1); however, this was reflected in a decrease in biochemical content (μg·larva?1) only in Teredo navalis. During enforced starvation the major proportion of both the weight and caloric losses were due to protein. Lipid also contributes significantly to these losses whereas the contribution of carbohydrate was small. Larval oxygen consumption rates were determined directly by manometry and indirectly by estimates of decrease in caloric content during periods of enforced starvation. Direct and indirect determinations for T. navalis are described by the relationships R = 1.16 W1.05 and R = 0.98 W1.24 respectively where R is the respiration rate in nl O2 · larva?1 · h?1 and W is dry weight inclusive of shell in μg. Direct and indirect determinations for Bankia gouldi are described by the relationships R = 1.37 W1.25 and R = 1.81 W1.25 respectively. When data for both assay procedures are combined for each species the relationships R = 1.10 W1.07 and R = 1.44 W1.18 are obtained for Teredonavalis and Bankia gouldi respectively.  相似文献   

8.
Scaphopods (tusk shells) are infaunal marine predators that occur at locally high densities in coastal and deep‐sea mud habitats, and as consumers of foraminifera they are important in carbon cycling. We investigated oxygen metabolism and burying behavior of the scaphopod Rhabdus rectius and its responses to altered temperatures. These are the first measurements of oxygen uptake rates for any member of this taxonomic class. In response to elevated temperatures, oxygen uptake rates increased, but the ability of animals to bury themselves in sediment was compromised. Female scaphopods were significantly larger than males and, when corrected for body mass, oxygen uptake rates were consistently higher for female individuals than for males. This is consistent with previous anecdotal observations of females in other scaphopod species being larger and potentially more active. In conditions of declining oxygen availability, individuals of Rhabdus rectius showed strong oxyregulatory ability by maintaining the same oxygen uptake rate displayed in normoxic conditions. The ability to maintain normal metabolic functioning even in conditions of oxygen limitation would benefit a species living in a benthic environment that may be prone to temporary or transient anoxic events. Yet the decrease in normal escape response in moderately elevated temperatures indicates these animals may be at risk from rising sea temperatures.  相似文献   

9.
杨桃果实采后生理研究(综述)   总被引:1,自引:0,他引:1  
概述了国内外对杨桃果实采后主要营养成分的分析、呼吸、乙烯释放、主要生理病害,并介绍了不同贮藏条件或处理对杨桃果实采后贮藏性影响的研究概况。  相似文献   

10.
黄鳝血液生理参数的研究   总被引:7,自引:0,他引:7  
报道了健康黄鳝血液的几项生理参数。结果 ,红细胞 2 .37× 10 12 L ,白细胞 4.16× 10 9L ,血栓球 6 1.6× 10 9L ,血红蛋白 134 .5 gL ,红细胞最大脆性 0 .35 % (NaCL溶液 ) ,血沉 1.0 5mmh ,凝血时间 1.75min。并将黄鳝的血液生理参数与其它几种鱼类作了对比分析  相似文献   

11.
试析世纪之交植物生理学研究的动向   总被引:2,自引:0,他引:2  
简要介绍了当今植物生理学研究中值得注意的四个动向,它们是从研究生物大分子到阐明复杂生命活动——基因组学、基因结构与功能的研究;实现生命整体性的重要环节——信号传递的研究;生命活动的能量和物质基础——代谢及其调节的研究;植物与环境(非生物和生物环境)的相互关系——生物的协同进化和适应的研究。  相似文献   

12.
柽柳的水分生理特性研究进展   总被引:71,自引:3,他引:68  
研究和了解柽柳的水分生理特性,是对柽柳合理利用和科学管理的重要前提。在对柽柳水分生理特性多年综合研究(P-V曲线、清晨水势及水势日变化和蒸腾速率)的基础上,对国内外研究柽柳水分生理特性的一些方法和手段进行了评述,以期尽快掌握柽柳的生态特性,为干旱、半干旱区域柽柳的恢复和保护提供一定的理论依据。  相似文献   

13.
Millions are rendered blind or exhibit visual impairment due to pathologies of the lens of the eye. Lens research therefore addresses the direct need to gain insights into the cellular and molecular basis of disease, but, moreover, serves as a valuable experimental system to answer fundamental biological questions. This themed issue showcases the scientific knowledge of the processes involved in the development, structure, ultrastructure, physiology and pathology of the lens and how this information has the potential to significantly further knowledge in various fields of research. The issue is divided into three main areas. Firstly, the lens is discussed as a developmental model for embryonic induction, as an elegant system for studying the role of growth factors in development, and for analysis of the molecular control and cellular basis of cellular differentiation. The genetic basis of disorders of lens development, including paediatric cataract (lens opacity), are also discussed in this section. Secondly, adult lens structure and ultrastructure are covered, as well as the lens as a model for homeostasis and solute exchange. Finally, the papers in the latter part of the special issue review lens pathology, including the lens as a model for normal and pathological ageing, vitreoretinal influences on lens function and cataract and the lens as a model for fibrotic disease. Overall, the articles highlight the lens as a continuing, very important and attractive model system for biologists working in many different research areas.  相似文献   

14.
15.
16.
孔子鸟(Confuciusornis)骨骼微观组织结构初步研究   总被引:3,自引:1,他引:2  
基于孔子鸟(Confuciusornis)股骨骨骼的微观组织结构与现生鸟类的相似性,认为孔子鸟具有较高而恒定的生长率,其新陈代谢可能已进化到相当高的水平,这种较高的代谢水平的起源要晚于鸟类的系统起源.鸟类骨骼内部的组织结构特征与骨骼外部的形态特征的进化是不同步的。孔子鸟等的祖先类型应是一生长速率较低而不恒定的、较原始的爬行动物。  相似文献   

17.
A study was conducted on bonefish Albula vulpes in The Bahamas to assess the utility of portable physiological diagnostic tools (i‐STAT analyser with E3+ ion and haematology cartridge, ACCU‐CHEK glucose meter and Lactate Pro lactate meter) for field physiology applications in remote locations. Physiological values derived from portable diagnostic tools were significantly related to values obtained from standard laboratory techniques [glucose (r2= 0·96), packed cell volume (PCV; r2= 0·33), Na+ (r2= 0·28), K+ (r2= 0·71) and Cl? (r2= 0·15)]. Actual values (i.e. intercepts), however, tended to deviate slightly between the two techniques. Nonetheless, these tools showed promise for documenting relative differences among fishes experimentally exposed to treatments inducing different levels of ‘stress’. These tools were then used to characterize the effects of different capture techniques on the stress response of A. vulpes. Albula vulpes captured in seines and then temporarily held in pens were physiologically sampled between 1 and 45 min postcapture to evaluate postcapture stress dynamics. Blood glucose and lactate as well as PCV and haemoglobin (Hb) increased rapidly after capture but stabilized at maximal values by c. 20 min postcapture. When angled, larger A. vulpes took longer to exhaust and land than did smaller individuals. In addition, there was a positive relationship between the magnitude of increase in lactate and the duration of the angling event, implying that anglers can reduce stress by minimizing the duration of the fight. Fish sampled before and after a simulated angling treatment displayed clear increases in blood lactate, K+, PCV and Hb, providing some of the first data on how individual A. vulpes respond to angling stress. In summary, this study revealed that techniques are now available for conducting field physiological studies on A. vulpes and possibly other species in remote locales, and that haematological and biochemical indicators of physiological disturbance vary with the intensity of the angling event.  相似文献   

18.
微弱发光分析技术应用实例(四)   总被引:7,自引:0,他引:7  
植物生理变化往往伴随着发光过程,探测这种发光过程,寻求其规律性,对于农业、林业科学研究具有重要意义.BPCL型微弱发光测量仪的样品室可以直接测量各种生物(植物、动物)体系的发光.超弱发光测量对于大豆种子生理变化敏感,有可能作为品种鉴定的手段之一.微弱发光动力学测量是具有应用前景的新方法,可用于多种植物的抗逆性研究.  相似文献   

19.
Studies of fish behaviour have demonstrated the existence of social interactions that result in dominance hierarchies. In environments in which resources, such as food, shelter and mates, are limited, social competition results in some fish becoming dominant and occupying the most profitable positions. This behaviour has been observed in natural environments and also in many laboratory‐based experiments. When two fish have been confined in a small tank, one of them usually has exhibited behaviour that suggests it is dominant over the other submissive animal. Physiological consequences of social interaction can be seen in both dominants and subordinates but are more extreme in the subordinate. However, this scenario is without doubt an artificial situation. Fewer experiments have been conducted using laboratory experiments that are more socially and physically complex than those experienced by dyads in tanks. In simple fluvial tanks, through which water is recirculated, the physiological responses of fish to social competition have generally been qualitatively similar to those recorded among dyads. However, when environmental disturbances, complex resource distributions, increase in water flushing, presence of predators and competing species of fish have been included in experimen‐tal designs, there have been fewer, diminished or no physiological dierences between dominant and subordinate fish. There have been very few studies of physiology in relation to dominance in natural habitats, and those that have been conducted suggest that under some circumstances hierarchies may cause less intense physiological responses than have been suggested based on results of laboratory studies in simple environments. Possible reasons for these variations are discussed. The need is identified for a well structured experimental approach to the investi‐gation of the causes and consequences of hierarchies if the ecology of wild fish is to be modelled eectively based on physiological processes. It is also suggested that the further development and application of techniques for monitoring physiologies of fish in the wild is important.  相似文献   

20.
激光诱变洋葱生理效应研究Ⅱ   总被引:4,自引:0,他引:4  
采用CO2和He-Ne两种激光的三种剂量,分别辐照两个洋葱品种的湿种子,采用生理生化的方法,从净同化率,净光合速率,呼吸速率,蛋白质含量等四个方面研究洋葱各处理的生物学效应。结果表明:He-Ne激光辐照洋葱的净同化率,净光合速率,呼吸速率,蛋白质含量的变异大于CO2激光辐照,采用He-Ne激光辐照洋葱容易从其变异后代中选择出高产,优质的优良变异株,进而育成符合育种目标的优良新品种。  相似文献   

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