The Transpiration rate of Abies georgei and the Correlation with Enviromental Factors

The transpiration rate of Abies georgei (20 years) was determined at sample plots on subalpine in Northwest of Yunnan Province. The result of annual change shows that the rate is from lower to higher monthly. The transpiration rate reached maximum value of 195.88 mgH20·gdw-1·h-1 in July, then, it decreases gradually in a open-grown sample leaf of the current year. The phenomenon of “noon-rest” shows that the curve for day change of transpiration rate is the form of double peaks. Statistical analysis proves that the variance of transpiration rate is influenced mainly by the environmental factors, particularly by temperature, relative humidity and light intensity. The correlations between transpiration rate and temperature, light intensity are positive and that between transpiration rate and relative humidity is negative. The variances of the transpiration rate on the elevations are different. The transpiration rate decreases with the increase of elevation in the natural forest area. Change is less in whole day at high elevation and light wave too. The rate of transpiration in clear cut over area is higher than in the area under deep canopy of a subalpine natural forest, they are 186.15 and 123.97 respectively Lastly, the correlation between transpiration rate and environmental factors and plant setting are discussed in this paper.     

On the Characteristics of Transpiration and Its Responses to Shade in Ginkgo biloba

With a CI-301PS portable photosynthesis system as a measuring device, a field study on the characteristics of transpiration and the responses of transpiration (E), stomatal resistance (R) and water use efficiency (WUE) to shade in Ginkgo biloba L. grown in Mt. Lushan was conducted. The results showed that with sufficient water in soil, the highest transpiration rate in a sunny summer day appeared in the afternoon. The WUE was maximum at about 8 a.m. and then decreased at noon remarkably. Different responses of E, R and WUE to shade were noticed which indicated that G. biloba was very suitable to the present climate. Moreover, the temperature of air, photosynthetic active radiation and R were the dominant factors affecting transpiration.     

光对水稻非光合组织谷氨酰胺合成酶同工酶表达的影响

以前的研究表明,高等植物叶绿体谷氨酰胺合成酶（GS2）受光调节,但叶片胞液GS（GS1）和非光合作用组织中的GS很少受光的影响,在本报道中,笔者运用GS活性染色和Western blotting研究了光对非光合作用组织水稻根GS同工酶表达的影响,在阳光的直接照射下以及在室内不同光照强度下,可以很清楚地观察到GSra和GS rb的活性带及其蛋白质带,但是,当用尼龙网档住阳光的直接照射下,GSrb的活性带和蛋白质带消失,当阳光被尼龙网遮挡住后,其光强度仍然比室内光照强度大得多,表明光照强度不是影响GSrb表达的主要因素,当分析生长在暗处以及生长在光／暗转换下的水稻幼苗根GS同工酶变化时,仍然可以观察到GSrb的在,在所有实验条件下,GSra都未发生明显变化,这些结果提示,光对GSrb表达的影响可能是由某些光谱相互作用所产生的未知因素造成的。     

干旱胁迫对4种植物蒸腾特性的影响

在温室条件下研究类芦等4种植物在干旱胁迫下的蒸腾特性。结果表明,在正常供水情况下,4种植物蒸腾速率和气孔阻力日变化规律明显;在干旱胁迫下,气孔阻力增大,蒸腾速率逐步降低,当水势下降到临界值时,气孔关闭,气孔阻力急剧增大,蒸腾速率降至最低。4种植物中,类芦的水分利用效率最高,其次为百喜草和香根草,五节芒最低。4种植物的抗旱力以类芦最强,百喜草和香根草其次,五节芒最弱。     

Effect of Stocked Fish on Rice Leaffolder Cnaphalocrocis medinalis and Rice Caseworm Nymphula depunctalis Populations in Intensive Rice Culture

It is often claimed that fish stocked in rice fields have a significant impact on the rice pest population. However, there is little experimental evidence for this. We used the data of six experiments to find out whether a polyculture of silver barb Barbodes gonionotus (Bleeker), common carp Cyprinus carpio (L.) and Nile tilapia Oreochromis niloticus (L.) has any effect on the population of rice leaffolders Cnaphalocrocis medinalis (Guenée) and rice caseworms Nymphula depunctalis (Guenée), two common pests in intensively cultured rice fields. Fish had no effect on the rice leaffolder population, but significantly lowered the number of rice caseworm adults and larvae. We concluded that fish have some effect on the arthropod pest population in rice fields, although, most probably, only on sluggish pests living in the water or on the water surface.     

茶树蒸腾特性的研究

茶树蒸腾速率和气孔导度因品种、叶位不同而异．抗旱性强的品种具有低的气孔导度;鱼叶的蒸腾速率和气孔导度接近或高于真叶．茶树叶片蒸腾速率夏、秋季最高,春季次之,冬季最低．在晴天,茶树蒸腾速率和气孔导度的日变化呈单峰型,以中午前后最高;其日变化与光量子通量密度、叶温、蒸汽压亏缺等因子显著相关;光量子通量密度对蒸腾速率和气孔导度影响较明显．     

Comparative Study on the Characteristics of Photosynthesis and Transpiration in Aneurolepidium chinense of Different Soil Types

The most striking difference in the characteristics of photosythesis and transpiration in Aneurolepidium chinense of different soil types was declined ratio of photosynthetic rate at light saturation point and maximum transpiration rate when the sufficient soil moisture became deficit. The declined range of photosynthesis in A. chinense of typical chestnut soil type was smaller than that of dark chestnut soil type and saline meadow soil type, but its declined range of transpiration was larger than that of the other two soil types. Therefore, using efficiency of solar energy and water of A. chinense of typical chestnut soil type was all higher at soil drought condition and adapitability itself to drought was stronger. These differences indicated that different edaphic ecotype of A. chinense can exist in natural condition.     

Effect of Tillage and Water Management on the Population Behaviour of Root-Knot Nematodes Meloidogyne Triticoryzae in Rice Crop

The effects of puddling and water regimes on hydraulic conductivity (cm/day) of soil and on bulk density (mg/m 3 ) during rice culture, soil physical characteristics of the experimental field population densities of plant-parasitic nematodes have been studied. Puddling reduced the bulk density of soil and decreased the hydraulic conductivity in the upper layers but not in the deeper layers of soil aeration was reduced due to high moisture levels retained in the puddled soil. Population density of M. triticoryzae declined in puddled soil. The invasion of the roots by the second-generation infective juveniles was reduced. The population density of the root-knot nematodes was higher in the non-puddled soil especially in unsubmerged condition compared to puddled and submerged soil. However, if the seedlings were already infected before transplanting and submergence, the nematode could survive well and reproduce within the aerenchyma of the root.     

不同氮素营养条件下内生真菌感染对黑麦草光合和蒸腾速率及生物量的影响

以黑麦草(Lolium perenne L)为实验材料,研究在不同氮素营养条件下内生真菌(Neotyphodium lolii)感染对其光合特性及生物量的影响.结果表明:1)整个实验中,内生真菌感染对黑麦草净光合速率、蒸腾速率以及水分利用效率均无显著影响,但在中氮和高氮水平时,感染种群的净同化累积值有超过非感染种群的趋势;2)在本实验的第一处理期和第二处理期,内生真菌感染对黑麦草绿色部分的干物质产量无显著影响,但在第三处理期感染种群的绿色部分的干物质产量显著高于非感染种群.     

Calcium Effect on the Process of Cold-Hardening of Rice Seedlings

Rice seedlings for cold-hardening were germinated from seeds treated with or without immersion in 30 mmol/L of CaCl2 solution. Change of membrane system protectivity in leaves at various periods (viz: following cold-hardening, chilling stress and on the 3rd day of recovery); the ratio of seedling survival and the ability of recovery were investigated. The results showed that cold-hardening increased the contents of endogenous antioxidants (the reduced form of glutathione, GSH; ascorhic acid, ASA), SOD activity and the content of heat stable protein in soluble protein. Cold-hardening combined with the CaC12 treatment of seeds enhanced the above-mentioned effects of cold-hardening, and obviously increased the activities of catalase (CAT) and peroxidase (POD). Both cold-hardening with or without the CaCl2 treatment reduced the declining degree of GSH, AsA content, the SOD activity and the heat stable protein content caused by chilling stress, augmented the increase in the level of GSH, AsA, CAT, SOD, POD and heat stable protein in the recovery periods. The CaC12 pretreatment especially had more effect on the level of heat stable protein, augmenting the A protein to rise to the level in normal seedlings. Furthermore, cold-hardened seedlings from seeds pretreated with CaClz grew faster and better in the recovery period of chilling stress than those from seeds without CaClz pretreatment. This promotive effect of CaC12 treatment on seeds prior to cold-hardening of seedling could be associated with an aug- mentation of membrane protectivity induced by the combined treatment.     

赤霉素对三个黑稻品种生长的作用

用 3个浓度的赤霉素对 3个品种的黑稻 (黑丰糯 ,黑粳 ,黑优粘 )的幼苗进行处理 ,结果表明 ,黑丰糯对GA的反应较为敏感 ,其生长的增加量与GA的浓度有近乎线性的关系 ,而黑粳及黑优粘对赤霉素处理的反应不明显。     

拟单性木兰不同季节断根和剪枝后蒸腾和光合特性的变化

在2005年春季、夏季和秋季,对10a生拟单性木兰(Parakmeriaomeiensis)进行断根和剪枝处理,模拟移栽,用LICOR-6400测定了植株叶片的蒸腾速率、光合速率等生理指标,探讨这些生理指标对不同季节移栽成活率的影响。结果表明,春季处理后叶片能迅速关闭部分气孔,蒸腾速率和光合速率都减小,两者最低时约为对照的60%,生理机能的减弱有利于维持地上、地下部分的平衡,因而最有利于植株成活。夏季处理后叶片气孔导度显著增加,光合速率和蒸腾速率也随之增大,最高时约为对照的2倍左右,此时,若主要依靠剪枝来降低水分消耗,很难保证水分代谢平衡,移栽成活率低。秋季处理后植株叶片气孔导度高于对照,光合速率和蒸腾速率也增加,但增加幅度相对夏季较小,前期最高约增加40%,此时移栽可以通过适当的剪枝和增加土壤水分含量等措施提高成活率。可见,与水分相关的生理机能的调节机制,决定了移栽后的成活水平,即处理后能迅速调节自身生理机能、减少水分消耗的植株,成活率就高,反之就低。     

农林复合系统中南酸枣蒸腾特征及影响因子

用热平衡法(Granier法)确定了南酸枣蒸腾量,研究了低丘红壤农林复合系统中南酸枣(Choerospondias axillaries)蒸腾的日变化特征、对复合利用方式及截枝处理的响应,并利用相关分析和多元逐步回归分析方法,探讨了影响蒸腾的因素.结果表明,蒸腾速率具有明显的早晚低、中午高的日变化特征,但在不同日期蒸腾速率日变化曲线存在一定差异,且在旱季晚间23:30后仍有茎流现象.南酸枣蒸腾主要受深层土壤水分的影响,与100 cm土壤深处的水势呈极显著正相关(R=0.737^**).农林复合,通过树木对深层水分的利用及微区域环境的改变,提高了植物蒸腾量40%～10%,为实现水分高效利用提供了可能.在影响蒸腾作用的气象因子中,光辐射强度、气温、地温是主要因子,而空气饱和水汽压差和风速次之.最后给出了依据气象因子估算茎流流速的统计模型.     

水分胁迫对入侵植物薇甘菊幼苗生长的影响

水分是影响薇甘菊(Mikania micrantha)生长的重要环境因子,但通过调控生长环境包括土壤水分和空气湿度来探讨这一入侵植物的适应能力的报道较少.本文通过设置2个水分梯度:处理Ⅰ土壤含水量30%～60%和空气相对湿度80%～90%,处理Ⅱ土壤含水量10%～20%和空气相对湿度20%～30%进行试验.结果发现土壤含水量在10%～20%且空气相对湿度在20%～30%时,水分胁迫能显著影响薇甘菊的幼苗生长和光合特性.胁迫条件下植株生长速率明显降低,最大净光合速率和最大量子效率分别是1.94 μmol·m-2·s-1和64.91 mmol·mol-1,比对照8.63 μmol·m-2·s-1和211.34 mmol·mol-1明显偏低.本文将空气相对湿度作为水分胁迫条件之一,阐述了空气相对湿度的增加能扩大薇甘菊的适生范围,并分析得出气孔限制可能是水分胁迫下薇甘菊生长受抑制的主要原因.     

水稻半胱氨酸蛋白酶抑制剂基因的克隆及其mRNA在水稻中的组成型表达

从40年代发现豆科植物中存在蛋白酶蛋白抑制剂以来,在动物、植物和微生物体内已发现普遍存在着多种类型的蛋白酶抑制剂(PI)。人们往往是为了研究某种蛋白酶的作用机制或出于某种应用目的去分离和研究PI的,对PI的真正生理功能尚不十分清楚。一般认为除防止体内不必要的蛋白降解作用、调节蛋白代谢及调节各种蛋白酶的生理活性外,很多植物的PI还具有抑制某些病源微生物及某些昆虫体内蛋白酶的作用,从而对植物有防卫功能。Hilder等和Johnson等已分别将属于丝氨酸蛋白酶抑制剂的豇豆蛋白酶抑制剂及马铃薯PⅠⅠ和PⅠⅡ基因转入烟草,结果转基因烟草对烟芽夜蛾(He-     

水稻花药培养植株后代的DNA变异

对籼稻圭６３０和粳稻０２４２８及其Ｆ１通过花药培养获得的８１个ＤＨ系进行了ＲＦＬＰ分析,有２８个探针揭示了ＤＮＡ变异。８１个ＤＨ系不同程度地发生了变异,并具有以下特点：（１）ＤＮＡ变异类型包括限制性片段长度的变化、９ＮＡ片段的丢失以及ＤＮＡ序列的扩增;（２）变异发生在籼稻圭６３０供体片段中的频率高于粳稻０２４２８,表现出基因型差异;（３）染色体组中第３、８、９和１０染色体较少发生变异,在其它染色体上均存在易变异位点;（４）在染色体的一些区段,相邻的探针均揭示了ＤＮＡ变异,表明在染色体上存在ＤＮＡ易变异区域;（５）变异位点和变异类型具有特异性,在同一位点不同的ＤＨ系中发生相同的变异。     

Effect of Photoperiodic Induction on the Transpiration Rate and Stomatal Behaviour of Debudded Xanthium Plants

In controlled-environment studies with debudded Xanthium plants,appreciable changes in stomatal activity and attendant ratesof transpiration were found to be associated with photoperiodicinduction. Leaves of plants kept on a 10-h inductive photoperiodafter removal of the apical and axillary buds grew at ratescomparable to those of similarly debudded plants kept on a 10-h-interruptednon-inductive photoperiod (consisting of an 8-h photoperiodand a 2-h interruption of the dark period). There was a large effect of leaf age on stomatal behaviour:the minimum stomatal resistance of leaves of non-induced plantsdecreased from about 5 s cm^–1 when the leaf was 25 percent of its final size to 1.6 s cm^–1 when almost fullyexpanded. Thereafter, it slowly increased with time. Superimposedon this age response was a marked effect of photoperiodic induction.The stomata on induced leaves opened more widely than thoseon non-induced leaves, the response being greatest with theleaves which were youngest at the time induction commenced.However, this ‘opening’ tendency was maintainedfor only a few weeks; thereafter, the stomata failed to openas widely. This later ‘closing’ tendency of stomataon leaves of induced plants progressed rapidly and in a basipetalsequence and presaged a necrotic form of leaf senescence whichdeveloped in the same sequence. The closing tendency on leavesof non-induced plants progressed slowly in an acropetal direction;leaves senesced in the same sequence with the familiar yellowingsymptoms. It is suggested that flower induction sets in train a sequenceof events which influence stomatal movement (and other processes)and inevitably leads to the death of the induced axis. Transpiration rates calculated from measurements of the physicalenvironments and stomatal resistances agreed well with thosemeasured.     

Changes in Stomatal Conductance,Transpiration and Water Use Efficiency of Ten Species Experienced in High CO2 Concentrations in Biosphere 2

The stomotal conductance, transpiration and water use efficiency (WUE) were measured using a LI-6400 portable photosynthesis system for 5 tropical rain forest species and 5 desert species in Biosphere 2, USA. All the species have experienced in very high CO2 ( > 2 200 μmol• mol- 1 ) for more than 4.5 years. The results showed that the stomatal conductance and transpiration of rain forest species decreased from ( 127.4 ± 65.6) and (2.04 ± 0.61 ) mmol• m- 2•s- 1 to (61.3 + 30.5) and ( 1.54 ± 0.65 ) mmol• m-2• s -1 respectively, while WUE increased from (2.90 ± 0.55) to (8.45 ± 2.71) μmol CO2 •mmo1-1 H2O, with CO2 increasing from 350 – 400 to 700 – 820 μmol• mol-l. For the desert species, stomatal conductance and transpiration decreased from respectively (142.8±94.6) and (2.09±0.71) mmol•m-2•s-1 to (57.7±35.8) and (1.36±0.52) mmolm-2•s-l, but WUE increased from (4.69 ± 1.39) to (9.68 ± 1.61) μmol CO2•mmo1-1 H2O, with the CO2 increase from 320 - 400 to 820 – 850 μtmol• mol- 1. The stomatal conductance, transpiration and WUE were less influenced by light intensity under high CO2 than low CO2 concentrations. Most rain forest species reached their light saturation points at light intensity of 500 μmol• m-2•s-1, while desert species at 1 000 μmol•m-2•s-1. Among different species, the desert C3 tree, Nicotiana glauca Grah., had the highest decrease in stomatal conductance and transpiration and the highest increase in WUE, by 78%, 69% and 310% respectively. The enhancement of increasing CO2 to the stomatal, transpiration and WUE of species with different photosynthesis pathway and life forms in Biosphere 2 could be concluded as: C3 species > C4 species, and desert C3 species > rain forest C3 species.     

Enhanced Treatment of Trace Pollutants by a Novel Electrolytic Cell

Continuous experiments were conducted to evaluate the electrolytic performance of a novel 3‐dimensional electrolytic cell consisting of granular Pt/Ti electrodes. The electric current efficiency to decompose indigotrisulfonate was approx. 96 %, while energy consumption was one to two orders of magnitude smaller than that for O₃ treatment. Furthermore, the cell was successfully applied to treat trace endocrine disrupting chemicals (EDCs) and chlorinated compounds. Energy consumption was in the range of 2 to 10 Wh/m³. From these results, it was concluded that the present electrolytic cell would be a feasible alternative to conventional oxidation processes in water treatment.