摘　要： 论述钾营养胁迫下，作物根系形态、根系分泌质子能力、根系钾离子吸收动力学过程、作物光合作用的变化趋势及特点，为进行作物耐低钾筛选及培育耐低钾新种质资源提供理论基础。

大田试验研究了不同钾肥追施量对烤烟生长及产质量的影响.结果表明,随追钾量的增加,烟叶钾、总糖不断增加,烟碱则呈降低的趋势.烟碱、总糖、还原糖、钾、糖碱比及氮碱比与追施钾量成显著或极显著相关关系,总氮、氯及钾氯比与追钾量无显著相关性.说明不同钾肥追施量对烟叶烟碱、总糖、钾及糖碱比和氮碱比的影响较大,在所试土壤中氮磷钾最适宜施用比例为1:1:3,各项经济性状均达最大值,初烤烟叶内在化学成分相对比较协调.

研究了不同高效钾用量下,烟草现蕾期光合速率的日变化、生长发育 过程中各部位烟叶钾含量的变化,结果表明:对照和K2SO4处理都有“午睡”现象,与K2SO4相比,高效钾肥能更好地改善烤烟光合性能.移栽后60d 前,烟叶钾含量随钾肥施用量的增加而增加,此后,钾肥用量增至一定量后继续增施烟叶钾含量不增反而下降,这种现象先从K2SO4处理中出现,烟叶部位先从 中、上部叶开始；烟株根、茎钾含量在移栽30 d时随施钾量的增加而增加,其他测定时期均为先增后降.在整个生育期中,除对照在第60d、75 d时钾含量表现为根＞茎,其他处理在所有测定时期中均表现为茎＞根.

在大田施氮、磷水平相等的条件下，采用随机区组设计，研究了不同施钾量对烤烟品种“K326”不同生育时期农艺性状、经济性状、主要化学成分、缺钾症状表现和气候斑病发生状况的影响。结果表明，在烟株生长前中期，当施钾水平达到每公顷180kg以上时，株高增长显著变慢，而定型株高极显著增高；茎围、最大叶的面积、叶面积指数(LAI)在每公顷施用135kg钾以上的处理与CK之间的差异性达到极显著水平；小区产量，折合单位面积和产值以每公顷施钾180kg(处理4)最高，中上等烟比例和均价以处理5(施钾225kg·hm~(-2))居首位，这两种处理的产量、均价和产值与CK之间存在极显著性差异；烟叶中总糖和K_2O含量随施钾水平提高而上升，烟碱、总氮、蛋白质和氯离子含量则下降，施木克值、糖碱比和钾氯比也随之提高；缺钾症状随着施钾水平提高而减轻，到处理4已无缺钾症状；烟叶气候斑病病情指数也随施钾水平提高而下降。

 To understand leaf photosynthesis characteristics and its response to K starvation in oilseed rape, a field experiment was carried out on K-deficient soil with K deficiency (–K) and K supply (+K) treatments. Gas exchange, chlorophyll fluorescence and chloroplast ultrastructure were studied using winter oilseed rape cultivar Zheyou 601 during over-wintering period. Results showed that leaf net photosynthetic rate (Pn) decreased by 45.1% under –K condition. Although stomatal conductance (gs) was lower in –K treatment than in +K treatment, intercellular CO2 concentration (Ci) increased 66 μmol CO2·mol-1 . Limiting value of stomata (Ls) decreased by 45.7%. Thus the stomatal factor changes were not the main reason for Pn decrease under –K condition. Further evidences from chlorophyll fluorescence measurement showed that both photosystem II (PSII) maximum photochemical quantum yield (Fv/Fm) and PSII actual photochemical quantum yield (ΦPSII) were declined under -K treatment, which indicated that PSII reaction center was damaged. In addition, K deficiency affected chloroplast ultrastructure of leaves. In K deficient plants, chloroplast length decreased significantly (with the average of 15.6%). Chloroplast thickness and distance from chloroplast to cell wall increased by 26.9% and 56.1%, respectively. In conclusion, the non-stomatal factors, e.g. damaged PSII reaction center and chloroplast ultrastructure alteration inhibited leaf Pn under K deficiency.

为了明晰缺钾胁迫下光合速率下降的主导因素及其作用机制，在田间条件下设置正常供钾处理（+K）和缺钾处理（–K），采用气体交换和叶绿素荧光联合测定技术以及透射电镜技术，研究缺钾胁迫时越冬期甘蓝型油菜品种浙油601的光合特性及叶绿体超微结构。结果表明，缺钾胁迫时叶片光合速率下降了45.1%。尽管缺钾胁迫下叶片气孔导度（gs）明显降低，但其胞间CO2浓度（Ci）增加了66 μmol CO2·mol-1，气孔限制值（Ls）减小了45.7%，说明气孔因素并非缺钾胁迫下油菜叶片Pn下降的主要原因。进一步的叶绿素荧光参数测定结果表明，缺钾胁迫导致油菜越冬期叶片PSII潜在光化学效率（Fv/Fm）和实际光化学效率（ΦPSII）显著下降，说明光系统II反应中心受损；并且缺钾胁迫下油菜叶片叶绿体的长度降低了15.1%、叶绿体厚度增加了22.7%、叶绿体到细胞壁的距离增加了56.1%。由此可见，缺钾胁迫下越冬期油菜叶绿体结构改变及光系统反应中心受损等非气孔因素导致叶片光合速率下降。

Spring wheat is one of the main grain crops in Heilongjiang province of China. The annual planted area is about 0.2 million hectares. The yield and quality of the spring wheat in the province is below the medium level in the country. So it is an urgent problem to enhance the yield and the quality. Potassium is not only the essential nutrient for crops growth and development, but also an important element in quality formation. The aim of the paper is to study the effect of potassium on the physical characteristics, yield and quality of spring wheat, and to provide technical support for high yield and high quality and high efficiency fertilization for wheat production in Heilongjiang province. The methods of pot culture and field experiment were adopted to study the effect of potassium on the physiological characteristics, yield and quality of the spring wheat. There were 5 treatments for the pot culture experiment and the rate of potassium (K 2 O) was 0, 0.05, 0.10, 0.20, 0.50 g/kg. The samples of the second leaf from the top of the wheat plants at the stages of three-leaf and jointing and the samples of the flag leaf at the stages of blooming, filling and maturing were collected for the determination of chlorophyll content, photosynthesis rate and the activity of nitrate reductase. The result of pot experiment showed that potassium could increase the chlorophyll content in the leaves. With potassium application, the chlorophyll content in the leaves increased by 0.51, 0.37, 0.75, 0.55 and 0.28 mg/g from three-leaf stage to maturing stage respectively compared to the control, on average. Among these, the optimum rate for the increase of chlorophyll content was K 2 O 0.10g/kg. With potassium application the rate of photosynthesis increased by 0.44, 1.87, 2.11and 1.49 μmol/(m 2 s)from jointing stage to maturing stage respectively compared to the control, on average. Among these treatments, the optimum rate of potassium for photosynthesis was K 2 O 0.20g/kg. Potassium also showed a good effect on the activity of nitrate reductase of the spring wheat. With potassium application the nitrate reductase activity(NRA) increased by NO 2 - 17.7, 17.6, 21.9, 23.9 and 13.5 μg/(gh),FW from three-leaf stage to maturing stage respectively compared to the control, on average. Among these treatments, the optimum rate of potassium for NRA was K 2 O 0.20g/kg.The field experiments were conducted in the main region of spring wheat production in Heilongjiang province. The soils for the experiments were black soil and planosol. There were 5 treatments with 3 replications. The rate of potassium was (K 2 O): 0, 22.5, 37.5, 52.5 and 82.5 kg/ha. The experimental result showed that potassium had a significant effect on the yield and quality of spring wheat. On the view point of yield and quality, the optimum rate of potassium for wheat in Heilongjiang province was K 2 O 37.5-52.5 kg/ha, the yield increased by 3.8%-18.1%, the average was 9.9%. Appropriate rate potassium application could improve wheat quality, especially on the processing quality. Compared the treatments of potassium with control, the protein content increased by 0.36 percent, wet gluten content by 2.33 percent, sedimentation value by 3.07mL, time of stability by 4.13 min, the maximum resistance by 10.2 EU, the extensibility by 1.4cm and the bread volume increased 10.4mL, on average. Potassium application could affect the components of protein in wheat. Compared the treatments of potassium with control, aibumine content increased by 0.14 percent, globumine content by 0.13 percent, glutenine content by 0.39 percent and prolamine content decreased by 0.42 percent.

采用盆栽和田间试验方法研究钾对春小麦生理特性、产量和品质的影响。盆栽试验设5个处理,于三叶期和拔节期采植株倒二叶,于开花期、灌浆期和蜡熟期采植株旗叶测定叶绿素含量、光合作用速率和硝酸还原酶活性。结果表明,适量的钾肥能提高小麦叶片叶绿素含量和光合作用速率,增加硝酸还原酶活性,延缓叶片衰老。田间试验在黑龙江省小麦主产区黑土和白浆土上进行。试验设5个处理,于收获期测产,并取子粒样品进行品质分析。试验结果表明,黑龙江省春小麦钾的适宜用量为(K 2 O)37.5～52.5kg/hm 2 ,施钾平均增产9.9%;适量的钾肥能提高小麦品质,尤其是对加工品质效果显著。

摘　要： 采用Li-6400光合仪测定了中绥12杨的光响应数据.分别采用直角双曲线模型、非直角双曲线模型、直角双曲线修正模型及指数模型对光响应曲线进行拟合,以探讨几种模型对中绥12杨的适用性并介绍在DPS数据处理系统中的操作步骤.结果表明,直角双曲线、非直角双曲线及指数模型得到的最大净光合速率大于实测值;直角双曲线和非直角双曲线模型得到的光饱和点远小于实测值;应用指数模型时（假设0.9Pnmax或0.99Pnmax所对应的光强为Isat）则无法求解光饱和点;直角双曲线修正模型拟合得到的各项光合参数均与实际相符,是中绥12杨光合光响应的最适宜模型.

摘　要： 利用直角双曲线修正模型和非直角双曲线模型拟合了三叶鬼针草、水稻和冬小麦的光响应曲线并进行了对比研究。拟合结果表明：非直角双曲线模型可以很好地拟合植物不出现净光合速率随光强增加而降低的光响应曲线,但得到的最大净光合速率大于实测值。此外,该模型不能很好地拟合植物净光合速率随光强的增加而降低的光响应曲线,且最大净光合速率低于实测值。直角双曲线修正模型则可以拟合植物在不同生境下的光响应曲线,且拟合得到的光合参数与实测值符合,这为研究植物在不同生境下的光合特性提供了一个更有效的工具。

Light responsive curve models have been widely used in plant physiological studies. However, most of the researchers emphasize their study aims, ignoring the practicability of the used models to their special plant materials. In this paper, 7 different light responsive curve models were compared to investigate the fitted effects using birch( Betula platyphylla Suk.) and larch( Larix gemelinii (Rupr.)Rupr.). The fitted results using the different models for the same species were different. Furthermore, the fitted results using the same model for the leaves of different parts of the same species were different also. These results indicated that it is necessary to consider the practicability when a model is used to a selected plant species and the optimal model is essential to ensure the accuracy of the estimated physiological parameters.

光响应曲线研究方法被广泛应用在植物生理的研究中，但是在应用光响应模型拟合光响应数据时，往往只考虑到研究的目的，很少考虑到模型是否适用于所研究的植物。本文通过采用7个不同的光响应模型对白桦叶片和兴安落叶松针叶光响应曲线数据拟合的比较，发现不同模型对同一种植物光响应曲线的拟合结果存在着差异，同一模型对同种植物不同部位叶片光响应曲线的拟合效果也不同，所以在研究植物的光响应时，应考虑到所选光响应模型对该种植物的光响应情况的描述是否恰当。根据具体情况选择最佳模型，以最大限度地保证估测生理指标结果的精确性。

Compared between two analysis methods of the photosynthetic light-response curve data，the non-rectangular hyperbola model was found to be more objective to calculate the photosynthetic parameters and simulate the photosynthetic light-response curve when the data were processed by the nonlinear statistical regression function of SPSS software and combined with linear regression in the low light period. Binomial regression curve could simulate photosynthetic light-response curve data，but it could not calculate apparent quantum yield(φ) and explain that net photosynthetic rates (Pn) predicted declines quickly when photosynthetic photo flux density(PPFD)excesses the light-saturation point.

通过对光响应曲线数据两种分析方法的比较，发现使用二项式回归来拟合光响应曲线，不能计算表观量子效率且无法解释光强超过光饱和点后，模型预测的光合速率很快下降等问题；而运用非直线双曲线模型结合SPSS软件的非线性回归，并在低光阶段辅以直线回归作补充，能较客观地计算光响应曲线相关参数并绘制出拟合图形。

Aims Our objective is to compare a new photosynthetic light-response model with the non-rectangular hyperbola, rectangular hyperbola, and Prado-Moraes model in fitting data and obtaining the maximum net photosynthetic rate and the light saturation point. Methods We measured the light-response of photosynthetic rate of winter wheat ( Triticum aestivum ) under the same chamber CO 2 concentration and different air temperatures in North China Plain using a gas analyzer Li-6400. The measured data were simulated by the new photosynthetic light-response model and the non-rectangular hyperbola, rectangular hyperbola and Prado-Moraes models, respectively. Important findings The new photosynthetic light-response model shows advantage over the non-rectangular hyperbola, rectangular hyperbola, and Prado-Moraes models in fitting data on the maximum net photosynthetic rate and the light saturation point. The main photosynthetic parameters calculated by the new one were very close to the measured data ( R 2 =0.999 4 and R 2 =0.998 7). Results showed that the apparent quantum was not an ideal indicator to assess the light use efficiency of plants. We suggest the apparent quantum yield be replaced by the quantum yield at the light compensation point due to the unity of the quantum yield for any C 3 plant species under certain environmental conditions.

用美国Li-Cor公司生产的Li-6400光合作用测定仪控制CO 2 浓度和温度, 测量了华北平原冬小麦( Triticum aestivum )的光响应数据。分别用C 3 植物光响应新模型、直角双曲线模型、非直角双曲线模型和Prado-Moraes模型拟合这些实测数据, 分析了由直角双曲线模型、非直角双曲线模型和Prado-Moraes模型拟合这些数据得到的最大净光合速率(The maximum net photosynthetic rate)远大于实测值, 而光饱和点(Light saturation point)远小于实测值的原因。结果表明, 由C 3 植物光响应新模型拟合的结果与实测数据符合程度最高( R 2 =0.999 4和 R 2 =0.998 7); 表观量子效率(Apparent quantum yield)不是一个理想的表示植物利用光能的指标, 建议用植物光响应曲线在光补偿点处的量子效率作为表示植物光能利用的指标。

讨论了光合作用对光响应新模型的一些特性.用新模型拟合超级杂交水稻新组合-Ⅱ优明86和丹参的光响应数据,并与用非直角双曲线模型、直角双曲线模型和二项式回归方法拟合结果进行了比较.结果比较表明:该模型不仅能处理植物在光抑制条件下的光响应问题,而且还能处理植物在低光强条件下的光响应问题.在光补偿点附近这两种植物的光合速率对光强的响应是非线性的.

摘　要： 为了寻求研制优质、高效、环保的烟草控释肥料所需的参考依据,采用田间试验研究了控释肥和烟草专用复合肥对烤烟光合特性、产量与质量及氮钾利用率的影响。结果表明：（1）当施氮量由90 kg/hm2提高到150 kg/hm2时,烤烟产量和产值均显著增加,上等烟比例和均价略有下降,各叶位烤后烟叶全钾含量提高或显著提高,烟碱含量显著提高,总糖与还原糖含量显著下降;（2）与烟草专用复合肥相比,控释肥可提高烤烟旺长期以后的叶片叶绿素含量,提高旺长期烟叶净光合速率、气孔导度、胞间CO2浓度,但对蒸腾速率无明显影响;（3）与烟草专用复合肥比较,控释肥能使烤烟产量提高3%-7%,产值提高9%-16%,各叶位烤后烟叶全钾含量提高或显著提高,烟碱含量变化不明显,总糖与还原糖含量降低。（4）控释肥有利于提高烤烟氮肥、钾肥利用率,在施氮90 kg/hm2和150 kg/hm2条件下氮肥利用率分别提高21.1和8.7个百分点,施钾180 kg/hm2和300 kg/hm2条件下钾肥利用率分别提高9.4和8.6个百分点。可见,控释肥可改善烤烟中后期光合特性,增加产量与产值,改善烤后烟叶品质,提高氮钾利用率。