Ecophysiology and Survival of Acer pseudoplatanus L., Castanea sativa Miller. and Quercus frainetto Ten. Seedlings on a Reforestation Site in Northern Greece

Seedlings of three tree species (Acer pseudoplatanus L., Castanea sativa Miller. and Quercus frainetto Ten.) were planted on a field site in Northern Greece to investigate factors connected to planting failures. On several dates, for the first two growing seasons after planting (1997 and 1998), leaf water potential, chlorophyll fluorescence, gas exchange variables and seedling survival were determined. Q. frainetto seedlings exhibited the lowest values of leaf water potential (Ψ) for most of the season in both studied years. Seedlings of all species showed large reductions in Ψ the mid-summer in both years, with particularly low values in 1998. In both years, a sharp reduction in Ψ was observed at the beginning of July when all three species exhibited their lowest net CO₂ assimilation (A) rate by the end of July. In 1997, A recovered after the July depression to values even higher than those recorded in June. However, in 1998, only Q. frainetto and to a lesser degree C. sativa recovered from a similar July depression in physiological values. Species reached their highest A rates by the end of August in 1997 and in June during 1998. In general, stomatal conductance and transpiration rates paralleled the A patterns. In 1997, the seasonal course of effective quantum yield (ΔF/F_m), for all plant species followed a rise-and-fall pattern with a peak at the beginning of July. In 1998, ΔF/F_m values were relatively high in June, showed a deep depression during July and while Q. frainetto and C. sativa recovered afterwards, A. pseudoplatanus continued to exhibit very low values. This study showed that differences in mortality between species were due to differences in tolerance to water stress and the superiority of Q. frainetto was probably related to the fact that it was the only species native and adapted to the planting site     

Plant VOCs emission： a new strategy of thermotolerance

Plant leaves may emit a substantial amount of volatile organic compounds （VOCs） into the atmosphere, which include isoprene, terpene, alkanes, alkenes, alcohols, aldehydes, eters, esters and carboxylic acids. Furthermore, most of these compounds actively participate in tropospheric chemistry. Great progresses have been made in linking emission of these compounds to climate. However, the VOCs emission function in plant is still not clear. Recently, some evidence has emerged that the production and the emission of VOCs, such as isoprene and monoterpenes, which account for 80% of total VOCs, exhibit plant protection against high temperatures. These increases in VOCs emissions could contribule in a significant way to plant thermotolerance. This perspective summarizes some latest literatures regarding the VOCs emission-dependent thermoprotection in plant species subjected to high temperature stress, presents the achievement in studies concerning plant VOCs emission-dependent thermotolerance, and then exhibits the proposed mechanisms of such plant thermotolerance. Finally open questions regarding the plant VOCs emission were shown, and the future researches were proposed.     

3种芳香植物光合特性的比较研究

以香樟、白兰花和栀子花为试验材料,利用Li-6400型光合作用测定系统监测其叶片光合生理生态特性,并利用相关分析探讨了净光合速率和蒸腾速率与生理生态因子间的关系。结果表明:①白兰花叶片的净光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Cd)的日变化均呈不对称双峰曲线,具有明显的光合"午休"现象;香樟叶片的蒸腾速率(Tr)和气孔导度(Cd)的日变化呈单峰曲线,而净光合速率(Pn)的日变化均呈双峰曲线;栀子花叶片的净光合速率(Pn)和气孔导度(Cd)的日变化均呈不对称双峰曲线,蒸腾速率(Tr)的日变化呈单峰曲线;香樟和栀子花的光合"午休"现象不太明显。②3种芳香植物Pn、Tr、Cd和Ci的峰值出现时间不同步。③3种芳香植物的净光合速率日均值、气孔导度的日均值和蒸腾速率的日均值依次为白兰花>栀子花>香樟,但种间差异不显著;胞间CO2日变化中利用的CO2体积分数日均值依次为栀子花>白兰花>香樟,由此可见栀子花和香樟适应环境的能力比白兰花较强,生长发育稳定且易成活,在植物配置中应多利用栀子花和香樟。     

种植密度对辣椒DU01光合特性及产量的影响

以适于一次性采收的辣椒新品种DU01为试验材料,设置5个种植密度,对DU01的光合特性及产量构成因素等进行研究.结果表明,盛果期后,DU01的叶面积、气孔导度(Gs)、胞间CO2浓度(Ci)和蒸腾速率(Tr)随着密度的增加而降低,叶绿素a(Chla)、叶绿素b(Chlb)、类胡萝卜(Car)和总叶绿素(Chlt)含量随...     

Relationship between stomatal behavior and characteristics of photosynthesis and transpiration ofAdenophora lobophylla andA. potaninii at different altitudes

The photosynthesis and transpiration characteristics ofAdenophora lobophylla andA. potaninii, as well as stomatal behavior such as stomatal size, stomatal density, stomatal open and stomatal conductivity were measured at different altitudes. The relationship between the photosynthesis and transpiration characteristics and the stomatal behavior was analysed by correlation coefficient and path coefficient analysis with altitude changes. The results showed that the influences of stomatal behavior were not evident on the photosynthesis and transpiration characteristics ofA. Lobophylla, but evident on that ofA. potaninii. This study is supported by the National Natural Science Foundation of China (No. 39391500). Responsible editor: Zhu Hong     

烤烟配方肥增效剂对烤烟光合作用的影响初探

以烤烟K326为材料,探讨配方肥增效剂处理对烟草光合作用的影响。结果表明,增效剂处理能提高叶绿素含量,其中处理C叶绿素含量最高,对照最低;在减少肥料用量的情况下,增效剂处理对叶绿素含量影响不显著;增效剂处理对光合作用表现在增强了净光合速率(Pn),提高了水分利用率,降低了气孔导度(Gs)和胞间CO2浓度(Ci),蒸腾速率(Tr)差异不明显。     

密度对不同类型饲用玉米光合产物积累与转运的影响

对2种类型饲用玉米在不同栽培密度条件下光合产物生产和运转情况进行了研究。结果表明,青贮型玉米科多8号偏重于营养生长,其叶面积指数、干物质积累量大,二者随密度的变化其变幅较大;粮饲兼用型玉米陕单310偏重于生殖生长,其叶面积指数、干物质积累量较小,密度对其影响较小,耐密植。密度对2种类型玉米光合产物在器官中的分配比例及器官中光合产物的转运性能具有调节作用。科多8号和陕单310光合产物转移率较大的器官分别是叶片和茎秆。     

SO2对植物光合作用影响的研究进展

SO2对光合作用的影响一直是人们研究的热点。本文综述了SO2对光合色素、光合强度、叶绿素荧不光、电子传递、乙醇酸代谢和碳固定的影响，并对以后SO2的研究方向提出了展望。     

CO2, H2Oexchange and stomatal regulation of regenerated Camptotheca acuminata plantlets during ex vitro acclimatization

Introduction Micropropagation is an important tool for mass production of uniform plants because of its high efficiency, with good phytosanitary status and quality control. Considerable efforts have been directed to optimize the conditions for in vitro st…     

Photosynthetic Characteristics of Ash and Larch in Mixture and Pure stands

IntroductionDuringthepasttwodecades,studieshaverevealedthatgrowingash(Fnainusmandshurica)andlarch(LarlksPP.)togetherinaproperwaycanincreasetheproduc-tivityQfthestandsI"'}'-'].Theyieldimprovementmechanismsattributetotwoaspects,i.e.,theabovegroundandundergr…