不同光合途径植物红砂和珍珠猪毛菜幼苗对氮沉降及降水变化的光合响应

氮素和水分是影响植物光合特性的重要因素,而不同光合途径植物对水、氮的响应能反映出植物与环境的关系。为探究氮沉降和降水变化对C₃植物和C₄植物生长方式的影响,以C₃植物红砂（Reaumuria soongorica）和C₄植物珍珠猪毛菜（Salaola passerina）为研究对象,利用盆栽试验,设置不同氮沉降水平（0 g·（m²·a）^-1,4 g·（m²·a）^-1,8 g·（m²·a）^-1）和不同降水处理（W-30%,W,W+30%）,比较两种植物单生和混生下的光合色素、光合气体交换参数和叶绿素荧光参数等的差异。结果表明：水氮耦合使红砂和珍珠猪毛菜光合能力均增强,且在降水增加30%和施氮量8 g·（m²·a）^-1时达最大;红砂的叶绿素、净光合速率分别最大可增加3.63倍、1.19倍,珍珠猪毛菜最大分别增加0.95倍和1.13倍。二者混生显著提高红砂的光合能力,而珍珠猪毛菜的竞争加强,氮水耦合可显著减弱竞争强度,说明在未来氮沉降和降水增加环境下,有利于红砂-珍珠猪毛菜混生群落的发展。     

铅胁迫对滇白前生长、光合作用及叶绿素荧光的影响

为探讨铅胁迫对滇白前（Silene viscidula）生长、光合作用和叶绿素荧光的影响,本研究采用盆栽试验,对不同铅胁迫下（0,600,1 200,1 800,2 400和3 000 mg·kg^-1）滇白前的生长指标（株高、叶宽、萌条数和根长）、光合指标（根系活力、叶绿素含量、净光合速率、气孔导度、蒸腾速率、胞间二氧化碳浓度）和叶绿素荧光参数（初始荧光、最大荧光、可变荧光、最大光化学效率、潜在活性）进行了测定。结果表明：滇白前初始荧光,胞间二氧化碳浓度随铅浓度增大呈先降后升的趋势,生长指标、光合指标和叶绿素荧光等其他参数随处理浓度升高呈先升后降的趋势;除初始荧光,胞间二氧化碳浓度外,中、低浓度（≤ 2 400 mg·kg^-1）铅处理下,滇白前生长指标、光合指标和叶绿素荧光等其他参数显著高于或略低于对照（0 mg·kg^-1）,而在高浓度（3 000 mg·kg^-1）处理下,这些指标都小于对照。滇白前对铅具有较强的耐性,能用于土壤铅污染修复。     

新型光合菌肥的肥效及增产机理研究

通过田间微区试验,对新型固体光合菌肥在蔬菜作物上的肥效及增产机理进行了研究,结果表明:这种光合菌肥不但可以提高茄子、辣椒和番茄的产量,而且还能降低茄子、辣椒番茄的坏果率。叶面喷施2￣3次光合菌肥,对茄子和辣椒有明显的增产作用,茄子的产量比对照增加39.03%￣43.21%;辣椒的产量比对照增加17.33%￣27.86%。喷施对番茄增产作用不明显。光合菌肥灌根处理对茄子和辣椒不仅没有增产作用,反而还会引起减产。但灌根对番茄增产作用明显,番茄的产量比对照增加11.06%￣15.34%,并且产量有随施用量增加而增加的趋势。此外,茄子、辣椒、番茄用光合菌肥灌根能显著增加耕层土壤中有效氮、磷、钾和铁、锰、铜、锌的含量。     

Effect of Temperature Hardening on Growth, Carbohydrate and Protein Levels in Three Grain Crops

The effect of seedling pretreatment at different temperature levels and periods of exposure on growth, pigments, carbohydrates and proteins was studied in three grain crops; sorghum, wheat and barley at different stages of growth. Greater shoot-dry weights were obtained in sorghum with exposure for 15 hrs at 40 °C in the flowering, in wheat for 2 hrs at 10 and 40 °C in the fruiting and in barley for 15 hrs at 0 °C in the flowering stage. Increased root-dry weights were achieved by wheat with exposure for 4 and 15 hrs at all levels even at 0 °C in the flowering and for 15 hrs at 40 °C in the fruiting stage. Chl_a and Chl_b were more responsive in sorghum to higher temperature pretreatments than either wheat or barley. In sorghum the temperature extremes (0 and 50 °C) had resulted in a substantial reduction of Chl_a, and Chl_b in the fruiting stage. Lower and higher temperature-pretreatments had resulted in total available carbohydrate reduction in shoot and root of sorghum and wheat at the early stage, but the reverse was true later in flowering. In contrast, lower and higher temperature pretreatments had increased shoot-protein in sorghum and wheat in the vegetative and in sorghum in the flowering stage. Root-protein was more responsive to low temperature-pretreatments in sorghum and barley during the fruiting stage.     

Biochemical and Physiological Changes of Three Watermelon Cultivars Infested with Fusarium oxysporum f. Sp.niveum

The dynamic changes in membrane permeability, activities of disease-related enzymes, and contents of pathogenesis-relevant chemical compounds and photosynthetic pigments in root cells of three watermelon cultivars were studied after inoculation with Fusarium oxysporum f. sp. niveum at seedling stage. The results showed that the capacity of self-regulating and returning to normal status of cultivar Kelunsheng (resistant) was greater than that of a susceptible cultivar, Zaohua, in terms of malonaldehyde (MDA) content, relative conductivity, and activity of superoxide dismutase (SOD) and catalase (CAT). The resistant cultivar maintained a higher activity of dehydrogenase, higher content of vitamin C(Vc), and relatively lower content of soluble sugar than the susceptible cultivar. The content of soluble protein was higher in the resistant cultivar than that in the susceptible one at day 1 after inoculation. The capacities of the resistant cultivar to inhibit chlorophyll deterioration and maintain a higher carotenoid content were significantly stronger than those of the susceptible cultivar.     

再生水对3种紫花苜蓿光合特性及产量的影响

为节约城市清洁水源,扩大再生水的利用力度,确保紫花苜蓿的稳产,以3种紫花苜蓿为研究对象,探讨了不同灌溉水源下紫花苜蓿的叶片光合色素含量、光合及叶绿素荧光特性、生长季内的累积干草产量及累积植株生长高度.试验采用2种水分处理:清水灌溉和再生水灌溉.研究表明:使用再生水灌溉后,3种紫花苜蓿的叶片光合色素含量及其光合作用能力均没有受到影响;四季旺的株高没有显著变化,但其干草产量明显增加;WL 323HQ的干草产量和株高均没有显著变化;阿尔冈金的干草产量和株高均显著降低.     

辣椒制品中苏丹红色素的快速检测方法

提出快速定性、定量测定辣椒制品中苏丹红色素的薄层色谱-扫描法。试验确定展开剂成分比例,在V(石油醚)∶V(丙酮)∶V(乙酸乙酯)=100∶3∶4的条件下,利用薄层色谱法可使辣椒制品中的天然色素与苏丹红色素在高效硅胶板上完全分离,比较检测样品与苏丹红色素标准品的Rf值和斑点颜色即可定性判断食品中是否含有苏丹红色素。用扫描仪扫描展开后的样品获得色素斑点图像,应用BandScan软件测定苏丹红Ⅰ、Ⅱ、Ⅲ、Ⅳ标准样品的总灰度,以苏丹红点样量(μg)为横坐标x,总灰度值为纵坐标y,进行线性回归,定量测定辣椒制品中的苏丹红含量。试验结果表明,苏丹红Ⅰ、Ⅱ、Ⅲ、Ⅳ扫描值的相对标准差分别为1.01%、1.91%、0.68%和2.59%,说明本方法精密度很好。本方法分离效果好、灵敏度高,且经济、操作简便,适用于辣椒及其制品中苏丹红色素的定性定量测定。     

两优培九抽穗期倒二·倒三叶片光合膜部分光能转化特性的研究

[目的]在光合膜水平上对两优培九倒二、倒三叶的光能转化特性进行研究,进一步探讨功能叶倒二、倒三在抽穗期的生理变化,以揭示不同衰老程度叶片的光合功能。[方法]以抽穗期的两优培九为材料,测定倒二、倒三叶的叶绿素、类胡萝卜素、可溶性蛋白和可溶性总糖含量以及类囊体膜PSⅠ、PSⅡ电子传递活性、类囊体膜室温吸收光谱、类囊体膜室温发射光谱等指标。[结果]倒二、倒三叶的叶绿素和类胡萝卜素含量随采样时间的延长而下降;可溶性蛋白含量、可溶性总糖含量都下降,但倒三叶下降幅度比倒二叶大;PSⅠ电子传递活性都在不断下降,PSⅡ电子传递活性则先上升后下降;类囊体膜室温吸收光谱都是先上升后下降,两者的室温发射光谱则是先下降后上升。[结论]功能叶倒三在抽穗期的生理变化比倒二更明显,叶片的光合功能比倒二叶弱,衰老比倒二叶快。     

茶多酚双液相氧化制取茶色素参数研究

对茶多酚双液相酸性氧化制取茶色素的参数进行了研究,结果表明:除了搅拌速度和供氧外,茶多酚浓度、温度、氧化剂浓度、酯比例、反应时间和pH值均对茶色素中茶黄素(TFs)和茶红素(TRs)的形成有较大影响。相对低的茶多酚浓度、低的温度、低的氧化剂浓度、低的酯比例、短的反应时间和低的pH值有利于TFs的形成。在茶多酚浓度、温度、氧化剂浓度、酯比例、反应时间高值和pH低值时可取得较高的茶色素得率。     

高产棉花光合特性的初步研究

光照充足，而且照射时间长，是南疆棉区气候生态条件的一个重要特点。棉花光合速率较高，光合时间较长，光合产物形成与积累较多，可能是其高产的主要生理原因。棉花群体内部透光性有很大的差别，叶面积增形分布较伞形分布合理。通过棉田涓光系数的测定，在高密度栽培条件下，叶面积仍以3．0－3．5为宜。能否将叶面积系数3．5（封行期）作为南疆高产棉田群体高限的参考指标，尚须进一步研究。