作物高产性的光合碳同化生理限制因子分析

对影响作物高产的光合作用碳同化的生理限制因子进行了分析，提出内外因子结合考虑是提高作物的光合效率和产量的关键．     

UV-B辐射增强对野生绿豆幼苗生长的影响

以野生绿豆为试验材料,研究了不同辐照度（10μW／cm^2,20μW／cm^2）UV-B对野生绿豆幼苗生长及光合作用相关指标的影响．结果表明,UV—B处理抑制株高和生物量的增加,降低叶绿素含量和PSⅡ反应中心传递电子的能力,导致光合作用强度下降．作为一种保护性适应,UV—B辐射诱导了叶片的花青素和类胡萝卜素的合成,导致叶片的花青素含量和类胡萝卜素含量增加．上述抑制作用及诱导作用均具有剂量效应．     

Characterization of high-yield performance as affected by genotype and environment in rice

We characterized yield-relevant characters and their variations over genotypes and environments （locations and years） by examining two rice varieties （9746 and Jinfeng） with high yield potential. 9746 and Jinfeng were planted in two locations of Shanghai, China, during 2005 and 2006. The results show that there was a large variation in grain yield between locations and years. The realization of high yield potential for the two types of rice was closely related to the improved sink size, such as more panicles per square meter or grains per panicle. Stem and leaf biomasses were mainly accumulated from tillering stage to heading stage, and showed slow decline during grain filling. Meanwhile, some photosynthetic characters including net photosynthesis rate （Pn）, leaf area index （LAI）, specific leaf area （SLA）, fluorescence parameter （maximum quantum yield ofPSll, Fv/Fm）, chlorophyll content （expressed as SPAD value）, as well as nutrient （N, P, K） uptake were also measured to determine their variations over genotypes and environments and their relationships with grain yield. Although there were significant differences between years or locations for most measurements, SLA at tillering and heading stages, Fv/Fm and LAI at heading stage, stem biomass at heading and maturity stages, and leaf nitrogen concentration at tillering and heading stages remained little changed, indicating their pos- sible applications as selectable characters in breeding programs. It was also found that stem nitrogen accumulation at tillering stage is one of the most important and stable traits for high yield formation.     

构建C4水稻——一场新绿色革命的挑战

国际上正在探讨新绿色革命的突破口,企图在现有良好株型的基础上,提高叶片的光合效率,其中构建C4水稻可能是一条有效的途径.本文简述了转C4基因水稻的工作意义、技术途径、生理特点以及进一步研究的问题,为中国培育高光效超高产新品种提供参考.     

NaCl对二色补血草气体交换及非辐射能量耗散的影响

用不同浓度的NaCl处理泌盐盐生植物二色补血草幼苗,10天后测定叶片净光合速率、非光化学猝灭系数(MPQ)及其三组分的变化.结果表明:在较高盐浓度(200、400mmol/L NaCl)处理下,气孔限制因素是光合速率降低的重要原因.随着盐浓度的增加,NPQ逐渐上升,400mmol/L NaCl处理与对照差异极显著.较高盐浓度抑制了qT代表的保护机制,而qT和qI代表的保护机制则在逐渐增强,说明在不同盐浓度下二色补血草对光抑制的保护机制不同.     

干旱绿洲植物叶片光合作用特性及季节变化规律

针对西北干旱区绿洲经济作物葡萄树叶片光合作用特性及季节动态差异等相关问题,在甘肃省敦煌市南湖绿洲应用便携式光合作用-荧光测量系统GFS-3000,测定了无核白葡萄叶片的光合特性指标及相关生理、生态指标的季节变化.结果表明:6-9月的净光合速率随光照强度的增加整体呈先上升后平稳的趋势,最大净光合速率与表观量子效率季节变化规律一致,光补偿点和暗呼吸速率季节变化规律一致,净光合速率随CO_2分数的升高快速上升,而后增速缓慢并逐渐趋于稳定,最后出现下降趋势.最大净光合速率和羧化速率季节变化规律一致,单位叶面积氮质量与最大净光合速率表现出正相关关系.