罗甸小米核桃叶绿素含量测定方法研究

研究了直接浸提法与Arnon法从罗甸小米核桃叶片中提取叶绿素的效率,并比较了两种方法的优劣。结果表明：用丙酮、乙醇浸提法提取叶绿素的效率比丙酮、乙醇Arnon法高,以乙醇与丙酮体积比1∶1的混合溶液为浸提剂时,叶绿素浸提效率最高;分别在温度50℃、料液比1∶50、浸提5 h的条件下浸提效果最好;在温度为50℃、液料比为1∶40的条件下提取6.5 h,叶绿素的提取效率最高,且3个主要因素对浸提结果影响次序依次为：浸提温度〉浸提时间〉浸提料液比。     

Comparative stomach contents and growth of the juvenile black rockfish Sebastes inermis reared in illuminated and unilluminated cages

ABSTRACT:   The principal objective of the present study was to determine the positive effects of artificial illumination on the juvenile black rockfish Sebastes inermis by comparing stomach contents and growth between juveniles exposed to light and those maintained in the absence of light. The major prey items of juvenile black rockfish in illuminated cages were: copepods (% IRI  = 62.6); amphipods (% IRI  = 36.7); and polychaetes (% IRI  = 0.3), whereas those in unilluminated cages were: copepods (% IRI  = 93.3); amphipods (% IRI  = 6.1); and polychaetes (% IRI  = 0.4). The specific growth rates of the juveniles reared in illuminated cages (0.67%) were significantly higher than those juveniles maintained in the unilluminated cages (0.27%).     

Protein, carbohydrate, lipid and chlorophyll a content in Isochrysis aff. galbana (clone T-Iso) cultured with a low cost alternative to the f/2 medium

Growth, proximate composition and chlorophyll a content was estimated in static cultures of Isochrysis aff. galbana (clone T-Iso) to compare the quality and quantity of the biomass produced with an agricultural fertilizer medium versus f/2 medium. Culture of microalgae was done with controlled temperature, air flux of 4.5 l min⁻¹, salinity of 33‰ and an irradiance of 110±3 μmol m⁻² s⁻¹. Daily samples from the cultures were taken to estimate cellular density, proximate composition and chlorophyll a content during 7 days. Mean cellular density from samples with f/2 medium and with agricultural fertilizer were similar (no significance at P≤0.05), and mean growth rates of 0.62 and 0.61 doubling per day, respectively. Maximum similar values of protein content of 7.3 and 7.6 pg per cell were estimated on the 5th day in f/2 and agricultural fertilizer medium, respectively. Carbohydrate and lipid content decreased during the first 5 days corresponding to the exponential growth in both experiments. Higher content of carbohydrate (no significance at P≤0.05) was found in both media during the first 2 days, after 4 days the carbohydrates reduced three times theirs concentrations. Generally lipid contents in the cultures with agricultural fertilizer were significantly higher (P≤0.05) than f/2 medium. The chlorophyll a content increased exponentially during the culture, and its concentration was similar in both experiments. In conclusion, the cellular density and the biochemical constituents were similar when using either media. This fertilizer can be used in the production of I. galbana (T-Iso) employed in aquaculture.     

厚层基材喷射植被护坡的水分常数分析

根据中国科学引数据库2004年的期刊引证报告，《水土保持通报》2003年总被引频次为526次(2002年，342次)，全国排名第288位(2002年，369位)，在全国农业类期刊中排名第13位(2002年，21位)；影响因子为O．417(2002年，O．37)，全国排名第437位(2002年，395位)，     

基于图像处理的烘烤过程中烟叶含水量检测

【目的】量化烘烤过程中烟叶形态变化的数值特征指标,实现烘烤过程烟叶水分含量的无损检测。【方法】以密集烤房中不同烘烤阶段的烟叶为研究对象,先利用图像处理技术提取鲜烟叶及烘烤过程中烟叶图像的颜色特征（红分量（R）、绿分量（G）、蓝分量(B)）及纹理特征(纹理能量、纹理熵、纹理惯性、相关度),以其为输入指标,分别建立烘烤过程中烟叶含水量的BP神经网络模型和基于遗传算法的最小二乘支持向量机预测模型。用建立的2个模型对烘烤过程中烟叶含水量进行预测,并比较其预测精度。【结果】烟叶图像颜色特征R、G、B分量表现出变黄期剧烈上升,定色前期缓慢上升并达到最大值,定色后期至烘烤结束逐渐下降的变化趋势;纹理能量和相关度呈现出变黄前期减小,变黄后期增大,定色及干筋期逐渐减小的趋势;纹理熵、纹理惯性表现出变黄前期增大,变黄后期减小,定色及干筋期逐渐增大的趋势。以烟叶颜色和纹理特征值作为输入变量,建立了烘烤过程中烟叶含水量的BP神经网络预测模型和基于遗传算法的最小二乘支持向量机预测模型,其预测平均绝对误差分别为0.037 4和0.017 0,预测误差标准差分别为0.048 5和0.020 0,前者预测精度略低于后者,但2个模型均可以满足烘烤过程中烟叶水分含量实时检测的需要。【结论】图像处理技术可以精确量化烘烤过程中烟叶的形态特征变化;利用建立的BP神经网络模型和基于遗传算法的最小二乘支持向量机模型可以实现对烟叶含水量的精确估测。     

壳寡糖席夫碱对感染烟草花叶病毒烟株叶绿素含量的影响

测定5种壳寡糖席夫碱3个浓度对烟草花叶病毒的抑制效果,结果显示,壳寡糖席夫碱对烟草花叶病毒(TMV)具有一定的诱导抗病效应,其中100μg/mL的3,5-二氯水杨醛壳寡糖席夫碱药剂的效果最好。并用该药剂对豫烟5号进行处理,测定了其对烤烟叶片中叶绿素含量变化的影响。结果表明,壳寡糖席夫碱可以有效诱导烟草抗烟草花叶病毒活性,处理后的烟草叶片中的叶绿素和胡萝卜素含量较阳性对照有较大的提高。     

早播下不同类型小麦品种叶片光合及籽粒灌浆的差异

为给安徽麦区旱播条件下小麦品种类型选择提供依据,通过2年多点(蒙城、阜南、濉溪)试验,比较分析了早播下不同类型小麦品种的叶片光合性能及籽粒灌浆特性。结果表明,早播下冬性品种烟农19和济麦20的叶片叶绿素含量最高,半冬性品种皖麦52和周麦22次之,偏春性品种豫麦70-36和周麦23最低。冬性品种叶面积指数和群体干物重显著高于偏春性品种。相同类型小麦品种间叶绿素荧光参数Fo、Fm、Fv/Fm、ETR和ΦpsII差异皆不显著,但冬性与偏春性品种间差异显著。冬性品种平均灌浆速率高于偏春性品种,穗数、穗粒数、千粒重和产量皆以冬性品种最高,其中蒙城点冬性品种烟农19产量比偏春性品种豫麦70-36和周麦23分别增加了37.6%和38.4%,济麦20的产量分别比豫麦70-36和周麦23增加了37.5%和38.3%。     

Responses of Contrasting Rice （Oryza sativa L.） Genotypes to Salt Stress as Affected by Nutrient Concentrations

The study was conducted to investigate the effects of applying different concentrations of the macronutrients K+,Ca2+,and Mg2+on the responses of contrasting rice(Oryza sativa L.)genotypes under salt stress.A solution culture experiment was conducted in a phytotron at the International Rice Research Institute(IRRI),under controlled temperature and humidity and natural sunlight.When subjected to salt stress of 100 mmol L-1 using NaCl,the salt tolerant genotypes FLA78 and IR651,accumulated less Na+and maintained lower ratios of Na+/K+,Na+/Ca2+,and Na+/Mg2+than the sensitive genotypes IR29 and Azucena.These tolerant genotypes also had higher concentrations of K+in their shoots and greater root and shoot biomass and green leaf area.Tolerant genotypes also maintained much lower concentration of Na+and lower and more favorable ratios of Na+/K+,Na+/Ca2+,and Na+/Mg2+in their active and developing tissues.Salt tolerance and shoot and root growth of both tolerant and sensitive genotypes were enhanced considerably when higher concentrations of Ca2+and Mg2+were applied in culture solution.The concentration of Na+and the ratios of Na+/K+,Na+/Ca2+.and Na+/Mg2+ in shoots also declined significantly.The beneficial effects of higher calcium were greater than that of magnesium and application of higher concentration of K+seems to have minor effects.Responses to salinity in rice can therefore be considerably enhanced through proper nutrient management,by increasing the concentrations of nu～ient elements that have favorable effects such as Ca2+and Mg2+Calcium is particularly more effective than both magnesium and potassium,and can be applied at relatively larger quantities in salt affected soils.     

Restoration ecology of coastal lagoons: new methods for the prediction of ecological trajectories and economic valuation

相似文献   

除草剂对黄芩叶片光合特性及叶绿素荧光参数的影响

试验采用随机区组设计,在黄芩幼苗期喷施骠马、精喹禾灵、收乐通、烟嘧磺隆和世玛等除草剂。研究了5种除草剂对黄芩幼苗光合作用相关的叶绿素、净光合速率、气孔导度、胞间CO2浓度以及荧光参数的影响。结果表明:按5种除草剂的推荐浓度处理后,叶绿素含量与CK相比分别下降了12.29%、14.29%、5.44%、27%、40.53%;净光合速率分别下降了11.68%、17.32%、16.5%、40.1%、52.5%;而荧光参数则表现出喷施骠马、精喹禾灵、收乐通后各项指标下降或升高的幅度小于喷施烟嘧磺隆、世玛各项指标的变化。除草剂对黄芩叶的光合和叶绿素荧光特性的影响表现出明显的剂量效应,即除草剂剂量越大,对黄芩叶片光合和叶绿素荧光特性的影响就越明显。由此得出结论:骠马、精喹禾灵、收乐通推荐剂量0.75kg.hm-2、0.6kg.hm-2、0.6kg.hm-2是比较安全的,而烟嘧磺隆、世玛推荐剂量1.52kg.hm-2、0.35kg.hm-2已对黄芩产生药害。