水杨酸对盐胁迫下辣椒种子萌发及幼苗生长的影响

该试验对NaCl胁迫下生长的辣椒幼苗进行水杨酸(SA)处理,分别采用浸种法和水培法在种子萌发期和幼苗期进行研究,以期研究外源SA对盐胁迫下作物生长的缓解作用,降低盐胁迫对作物的伤害,提高中、轻度盐碱地的利用率。结果表明:盐胁迫会抑制辣椒种子的萌发和幼苗生长,当SA浓度为0.15 mmol·L~(-1)时,种子的发芽势、发芽率等最高,缓解盐胁迫的效果最佳;利用外源水杨酸对盐胁迫下的辣椒苗进行生长调控,叶片的净光合速率(Pn)、气孔导度(Gs)显著降低,细胞间隙CO_2浓度(Ci)持续升高,表明SA可以缓解盐胁迫对植物的抑制作用,提高叶片光合作用的效率,同时与NaCl处理相比,叶绿素含量在第3、6、9天分别增加51%、34%、40%,这表明SA可以缓解盐胁迫对辣椒幼苗的生长抑制,促进叶片叶绿素的合成,保护其光合作用,维持植物的正常生长。     

GABA和CaCl_2复配对盐碱胁迫下番茄幼苗生长、叶绿素荧光参数和活性氧的影响

γ-氨基丁酸(GABA)对增强作物抗逆性发挥了重要的作用,而内源GABA的合成与胞内Ca~(2+)浓度相关。本试验以盐敏感型番茄品种中杂9号为试材,采用表型差异显著的盐碱胁迫浓度(60 mmol · L~(-1) NaCl + 60 mmol · L~(-1 )NaHCO_3),研究单独添加GABA和CaCl_2及两者复配组合对盐碱胁迫下番茄幼苗生长、叶绿素荧光和活性氧等指标的影响。结果表明:外源GABA和CaCl_2单独处理和复配处理均可提高盐碱胁迫下番茄的株高、茎粗、根长、根数生长速率,且幼苗鲜质量和干质量也明显上升;叶色指数显著提高,叶绿素荧光参数也得到明显改善;同时,外源GABA和CaCl_2单独处理和复配处理还降低了盐碱胁迫下番茄叶片活性氧的积累。与单独处理相比,复配处理SA + Ca6 + GABA5对于盐碱胁迫伤害的缓解效果更好,说明外源CaCl_2的添加对于GABA增强植物耐盐碱能力有促进作用。     

不同CaCl_2浓度对低温胁迫下豇豆幼苗生理指标的影响

为研究CaCl_2对蔬菜低温胁迫的缓解效应,以豇豆幼苗为试验材料,在10℃低温处理条件下用不同浓度(0、5、10、20、40 mmol·L~(-1))CaCl_2喷施豇豆幼苗叶片。结果表明,喷施CaCl_2能普遍提高豇豆幼苗生物量、相对含水量、光合色素含量、脯氨酸含量、可溶性糖含量及抗氧化酶活性,降低其相对电导率及丙二醛含量。且10 mmol·L~(-1)CaCl_2处理后,豇豆幼苗各部分生物量、光合色素含量达到最大,超氧化物岐化酶活性较对照增加99.6%、过氧化氢酶活性较对照增加29.49%,且相对电导率、丙二醛含量分别较对照降低62.07%、36.15%。因此,CaCl_2能够缓解低温胁迫对豇豆生理生态的影响,且浓度为10 mmol·L~(-1)的CaCl_2效果最好。     

重金属铬(Cr~(6+))对三色堇种子萌发及叶绿素含量的影响

以三色堇种子为试材,采用水培法,研究了不同浓度的Cr~(6+)胁迫对三色堇种子萌发及幼苗生长的影响,以期明确重金属铬对三色堇幼苗的危害及作用机制,为后续研究提供一定的参考依据。结果表明:发芽势和发芽率均在0～5.0mg·L~(-1) Cr~(6+)处理浓度范围内呈上升趋势,在5.0～80.0mg·L~(-1)范围内呈下降趋势;在0～80.0mg·L~(-1) Cr~(6+)处理浓度范围内,随着Cr~(6+)浓度的升高,三色堇幼根长度显著降低,幼芽长度先上升后下降,在2.5mg·L~(-1)时达到峰值;在0～5.0mg·L~(-1) Cr~(6+)处理浓度范围内能够使三色堇子叶中叶绿素a、叶绿素b和叶绿素总量上升,在5.0～40.0mg·L~(-1)范围内叶绿素a、叶绿素b和叶绿素总量下降。     

6-BA和GA3对NaCl胁迫下铁皮石斛幼苗生长及可溶性糖含量的影响

以铁皮石斛为试材,在NaCl胁迫下,研究了6-苄氨基腺嘌呤(6-BA)和赤霉素(GA3)对铁皮石斛幼苗生长、色素及可溶性糖含量的影响。结果表明:2.0mg·L~(-1) 6-BA可以显著提高NaCl胁迫下铁皮石斛幼苗根的生长率,而4.0mg·L~(-1) GA3则显著的提高其根的生长率,但二者均降低铁皮石斛茎的生长率;2.0mg·L~(-1) 6-BA则可以降低叶绿素b含量,而4.0mg·L~(-1)6-BA则可以提高叶绿素的含量,且不同浓度6-BA对叶绿素a和类胡萝卜素的含量无显著性影响;2.0mg·L~(-1) GA3均可以提高叶绿素a、叶绿素b和类胡萝卜素的含量,而6.0mg·L~(-1) GA3则降低叶绿素b含量;4.0mg·L~(-1) 6-BA和6.0mg·L~(-1) GA3均可以提高可溶性糖含量。因此,添加适当浓度的外源植物激素可以促进铁皮石斛中可溶性多糖的合成与积累。     

IAA和SA对盐胁迫下萝卜幼苗生理特性的影响

以萝卜为试材,研究了不同浓度的吲哚乙酸(IAA)和水杨酸(SA)(0、0.3、0.6、0.9、1.2、1.5mmol·L~(-1))对NaCl胁迫下萝卜幼苗生理特性的影响。结果表明:NaCl胁迫下萝卜幼苗的各项生理指标都发生了显著变化。经适宜浓度的吲哚乙酸和水杨酸处理后,萝卜幼苗的还原糖含量、脯氨酸含量、丙二醛含量和相对电导率显著降低,叶绿素含量显著升高,对盐害有一定的缓解作用。但是浓度过高,又会形成新的胁迫伤害。其中,IAA的最佳浓度为0.9mmol·L~(-1),SA的最佳浓度为0.6mmol·L~(-1)。     

外源H_2S处理对盐碱胁迫下垂丝海棠幼苗生理特性的影响

【目的】研究外源喷施硫化氢(H_2S)对盐碱胁迫下垂丝海棠幼苗光合及生理特性的影响。【方法】采用盆栽试验法,对8叶龄垂丝海棠幼苗共设6个处理,即清水浇灌(CK_1)、盐碱胁迫处理(CK_2)、盐碱胁迫+0.1 mmol·L~(-1)NaHS喷施处理(T_1)、盐碱胁迫+0.2 mmol·L~(-1)NaHS喷施处理(T_2)、盐碱胁迫+0.3mmol·L~(-1)NaHS喷施处理(T_3)、盐碱胁迫+0.4mmol·L~(-1)NaHS喷施处理(T_4),测定各处理的叶绿素含量、光合特性、荧光参数、抗氧化酶活性、相对电导率及渗透调节物质含量,并进行相关与主成分分析。【结果】随盐碱胁迫时间的延长,叶绿素a(Chl a)、叶绿素b(Chl b)、叶绿素a+b(Chl a+b)、净光合速率(P_n)、气孔导度(G_s)、蒸腾速率(T_r)、初始荧光(F_0)、光化学淬灭系数(q P)均呈下降趋势;胞间CO_2浓度(C_i)、调节性能量耗散(Y(NPQ))、非调节性能量耗散(Y(NO))、相对电导率(REC)均呈上升趋势;脯氨酸(Pro)、超氧化物歧化酶(SOD)、过氧化物酶(POD)均呈先升后降的趋势;相比CK_2,外源H_2S处理下各指标的上升和下降均有所减小,并具有浓度效应,呈现出随浓度升高先上升后下降的趋势;胁迫30 d时,各处理组的REC相比对照分别下降了22.16%、37.92%、20.92%、13.54%;Pro分别降低了17.99%、24.48%、16.58%、8.39%,表明H_2S处理具有浓度效应。T_2处理下Chl a、Chl b、Chl a+b、P_n、G_s、T_r、F_0及q P下降最少,且显著高于CK_2,低于CK_1;Y(NPQ)、Y(NO)、REC上升幅度最大;Pro、SOD、POD变化最明显。相关性分析结果表明,P_n与G_s、T_r、F_0、q P呈正相关,P_n与REC、C_i、Y(NO)、Y(NPQ)呈负相关。对上述指标标准化进行主成分分析,提取特征值1的2个主成分,其特征值分别为14.783和2.781,方差贡献率分别为82.128%和15.452%,累计方差贡献率达到97.58%。依据主成分得分排序,外源H_2S对垂丝海棠盐碱胁迫缓解能力由高到低为:CK_1T_2T_1T_3T_4CK_2。【结论】0.2 mmol·L~(-1)的外源H_2S可更好改善盐碱胁迫下垂丝海棠的光合能力、提高抗氧化酶活性、增加生物膜的稳定性,从而起到缓解盐碱胁迫的作用。     

三种肥料增效剂复配对樱桃番茄生长和品质的影响

以"金玲珑"番茄品种为试材,研究了复硝酚钠、DA-6、α-萘乙酸钠3种肥料增效剂复配后结合水肥一体化对连栋温室樱桃番茄生长和果实品质的影响。结果表明:3种肥料增效剂复配结合水肥一体施用,各处理与对照相比,均能促进樱桃番茄的株高,尤其是在生长前期,其中8mg·L~(-1)复硝酚钠+4mg·L~(-1)α-萘乙酸钠的处理对株高促进作用最明显,5mg·L~(-1) DA-6+8mg·L~(-1)复硝酚钠的处理次之。8mg·L~(-1)复硝酚钠+4mg·L~(-1)α-萘乙酸钠的处理对樱桃番茄的基部茎粗有明显促进作用,对樱桃番茄坐果数、坐果率、单果质量的影响差异性较小,对产量没有影响。各处理对樱桃番茄的维生素C含量有明显的增加,其中5mg·L~(-1)DA-6+4mg·L~(-1)α-萘乙酸钠,5mg·L~(-1)DA-6+8mg·L~(-1)复硝酚钠,8mg·L~(-1)复硝酚钠+4mg·L~(-1)α-萘乙酸钠相比较对照分别提高35%、119%、139%。     

水杨酸对番茄幼苗抗高温胁迫能力的影响

以"辽园多丽"番茄品种为试材,在高温(35℃/25℃)胁迫下研究了30、60、90、120mg/L水杨酸(SA)处理对番茄叶片叶绿素、可溶性糖、可溶性蛋白质,脯氨酸及丙二醛含量和对番茄幼苗抗高温胁迫能力的影响。结果表明:番茄幼苗叶片叶绿素、可溶性糖、可溶性蛋白质及脯氨酸含量均随着SA处理浓度的增大而增加,而丙二醛(MDA)含量则表现为先降低后增高。SA对高温胁迫的缓解作用受其浓度的影响,以90mg/L效果最好。     

不同浓度磷对茄子叶片光合及荧光特性的影响

为探求不同浓度磷对茄子幼苗光合、荧光特性的影响,采用水培方法,在Hoagland's基本营养液(CK)基础上,设置4个低磷处理。结果表明,对照的叶绿素和类胡萝卜素含量显著高于其他处理。净光合速率(P_n)、蒸腾速率(T_r)、气孔导度(G_s)随着浓度磷的增大不断增高,在0.60 mmol·L~(-1)磷含量时达最大值,且与其他处理差异显著。不同浓度磷处理下最大光化学效率(Fv/Fm)均值相近,说明在不同浓度磷处理下茄子叶片均能保持较高活力。综合分析表明,0.60 mmol·L~(-1)浓度磷即可满足茄子正常生长对磷的需求。     

Effects of sensor spatial resolution on landscape structure parameters

We examined the effects of increasing grain size from 20 m to 1100 m on landscape parameters characterizing spatial structure in the northern Wisconsin lake district. We examined whether structural parameters remain relatively constant over this range and whether aggregation algorithms permit extrapolation within this range. Images from three different satellite sensors were employed in this study: (1) the SPOT multispectral high resolution visible (HRV), (2) the Landsat Thematic Mapper (TM), and (3) the NOAA Advanced Very High Resolution Radiometer (AVHRR). Each scene was classified as patches of water in a matrix of land. Spatial structure was quantified using several landscape parameters: percent water, number of lakes (patches), average lake area and perimeter, fractal dimension, and three measures of texture (homogeneity, contrast, and entropy). Results indicate that most measures were sensitive to changes in grain size. As grain size increased from 20 m using HRV image data to 1100 m (AVHRR), the percent water and the number of lakes decreased while the average lake area, perimeter, the fractal dimension, and contrast increased. The other two texture measures were relatively invariant with grain size. Although examination of texture at various angles of adjacency was performed to investigate features which vary systematically with angle, the angle did not have an important effect on the texture parameter values. An aggregation algorithm was used to simulate additional grain sizes. Grain was increased successively by a factor of two from 20 m (the HRV image) to 1280 m. We then calculated landscape parameter values at each grain size. Extrapolated values closely approximated the actual sensor values. Because the grain size has an important effect on most landscape parameters, the choice of satellite sensor must be appropriate for the research question asked. Interpolation between the grain sizes of different satellite sensors is possible with an approach involving aggregation of pixels.     

基于DSP的果树形态结构参数检测

根据仿形喷雾的作业要求,开发设计了一套基于DSP的果树形态参数检测系统,可以对果树图像进行实时采集和处理,并快速计算出果树的部分形态结构参数。主要介绍检测系统的软件设计和果树形态参数的检测计算。经实验验证,系统对果树最大冠幅和高度的检测相对误差分别在-2.51%～0%和-3.0%～1.7%范围内,同时郁密度检测也基本上能够反映出果树的实际稀密程度。     

苹果四倍体品种叶绿素荧光参数的日变化

以同源四倍体品种天星、烟嘎1号和对应的二倍体品种富士、烟嘎1号为试材,研究了苹果四倍体品种叶绿素荧光参数的日变化规律.结果表明,初始荧光(Fo)、最大荧光(Fm)、PS Ⅱ原初光能转化效率(Fv/Fm)、PSⅡ的潜在光化学效率(Fv/Fo)、以吸收光能为基础的光合性能指数(PI)均存在明显的日变化.其中Fm、Fv/Fm...     

几种果树水分生理指标的比较研究

以盆栽２年生苹果、杏、桃和葡萄为试材，研究了水分逆境对果树水分关系的形响及差异。从正常灌水（田间持水量８０％）所测定的萎蔫点相对合水量（ＲＷＣｐ）、萎蔫点水势（ψｗｐ）和总体原初渗透压（ψｚ０）判断， ４种果树抗旱性的顺序是：杏、桃＞苹果＞葡萄。干旱下测定的 ３种参量所反映的结果与上述一致。４种果树正常灌水处理弹性大小的顺序是：苹果＞杏＞葡萄＞桃，最大体积弹性模量（Ｅｖ０）分别是：３８．７、４４．９、５１．７、５５．６ＭＰａ。干旱条件下使苹果、杏弹性变差，葡萄、桃弹性增大。Ｅｖ０分别是：７１．７６、９０．６７、５４．０８和４０．４８ＭＰａ，说明ＣＫ弹性好坏不能反映对长期干旱的适应性。弹性系数与膨压（ψｐ）成显著直线正相关，说明弹性越好（Ｅｖ０越小），维持ψｐ能力越强，有利于气孔开张、维持光合。Ｅｖ０小者（苹果、杏）， Ｅｖ０随ＲＷＣ降低而缓慢降低，细胞伸缩范围大。 水分协迫下，苹果、各具有明显的渗透调节作用，苹果ψｗｐ和ψｚ０分别比ＣＫ下降０．５和０．４ＭＰａ，杏分别下降 ０． ６１和 ０． ５９ＭＰａ，葡萄只具有微弱的渗透调节能力，ψｗｐ和ψｚ０分别下降 ０． １６和 ０． １３ＭＰａ，桃无渗透调节能力。多一位处理使     

Responses of eggplant to drought. II. Gas exchange parameters

Transpiration and net photosynthesis of eggplant (Solanum melongena L.) cultivar ‘Claresse’ were measured at decreasing leaf water potential (ψ_leaf). Attached single leaves were used in an open system and 6 levels of irradiance were applied. Mesophyll resistance to diffusion of Co₂ (r'_m) and stomatal resistance to diffusion of water vapour (r_s) were calculated from the gas exchange rates. As ψ_leaf declined, transpiration and photosynthesis decreased due to stomatal closure and an increase in r'_m in the case of photosynthesis. For the same degree of water stress, photosynthesis was maintained better in egg-plant than in other vegetable plants cited in the literature. Twenty four hours after the severely stressed plants were rewatered, gas exchange rates had not recovered completely. This was due to an after-effect of stress on the stomates, and to additional direct effects of drought on the photosynthetic system.     

Early growth habit and vigour parameters in olive seedlings

Fruit tree growth habit and vigour are important traits for orchard management and production, yet are difficult to select for in breeding programs because the parameters for their evaluation are complex, and their expression often requires sufficient plant size and development, entailing valuable time. Thus, in olive (Olea europaea L.) breeding, as for other fruit crops, it is critical to define growth habit and vigour parameters with selection potential, and to determine the earliest age at which they can be measured. Furthermore seedling growth habit traits are important in themselves, particularly in their relation to juvenile period length and management. To explore these issues we evaluated a series of new and standard growth habit parameters during the first year of growth in a population of unpruned olive seedlings originating from six different crosses. The influence of plant age on growth habit traits was determined by comparing measurements at two or three different times. Both parent genotype and plant age significantly affected the vigour and growth habit of the olive seedlings, and 9 months was the most appropriate age for evaluating seedling growth parameters. ‘Picual’, ‘Arbosana’ and ‘Sikitita’ were shown to be promising cultivars for use as genitors, because of their tendency to produce offspring with desirable growth habit traits such as high vigour, weeping habit and low lateral shoot number. From among the 17 parameters studied, based on parent influence and the absence of correlation among parameters, five were identified which best described olive seedling growth habit: Primary Shoot Top Diameter, Primary Shoot Conicity, Secondary Shoot Number, Secondary Shoot Insertion Angle and Longest Secondary Shoot Internode Length.     

Model parameters to describe the development of marketable yield of Brussels sprouts

A model, in three parts, describes the growth of Brussels sprout buttons, the wastage through unacceptable quality and the size distribution of the buttons. Some of the model parameters are assessed to establish whether they vary between cultivar and site. The rate of button growth is described in relation to thermal time above a base of -5°C and is independent of cultivar and site. A single parameter describes the time trend in the loss of yield through unacceptable quality. The yields of quality buttons in specific size ranges are described by a normal distribution where the mean represents the mean diameter of buttons and the standard deviation the spread of button sizes. The mean and standard deviation parameters are cultivar and site dependent. The standard deviation parameter is well related to the number of buttons per stem; the relation appears to be independent of site and variety. The model enables the marketable yield to be simulated using only simple and easily understood parameters. A sample simulation is presented.     

不同栽培基质对吊兰气孔参数的影响

通过对营养液水培、陶粒浇灌营养液、珍珠岩浇灌营养液、蛭石浇灌营养液、土培5种栽培条件处理下吊兰气孔参数的研究,结果表明,试验中所观察的吊兰叶片气孔呈圆型或椭圆型,保卫细胞半月形。靠近叶尖和叶中部位的气孔分布较叶缘和叶基的多,叶基部位气孔分布相对较少,从叶基到叶尖气孔密度逐渐增大,表现为：叶尖〉叶中〉叶基。不同栽培基质中吊兰叶片中段下表皮气孔参数相比较：土培处理的叶片中段气孔指数最大为41．63％,极显著地高于蛭石浇灌营养液、营养液水培、陶粒浇灌营养液处理;土培单个气孔面积最小,为896．98μm^2,极显著地低于蛭石浇灌营养液、营养液水培、陶粒浇灌营养液处理。     

Changes in parameters of cell senescence in carnation flowers after cold storage

The effects of cold storage on vase life, ethylene (C₂H₄) production, and parameters of cell senescence, were measured in flowers of spray carnation (Dianthus caryophyllus L.), cultivar ‘Pink Royalette’. Storage for 6 or 12 days at 2°C led to a reduction in the subsequent vase life at 20°C. In addition, storage caused a reduction in the time between the rise in ethylene production and the end of vase life. That is, cold storage increased the sensitivity of the petal cells to endogenous C₂H₄.Normal aging of flowers for 6 days at 20°C led to decreased capacity of petals to take up [¹⁴C] sucrose, decreased activity of membrane ATPase, increased membrane microviscosity and decreased membrane phospholipid content, relative to the levels in fresh flowers. However, cold storage of flowers for 6 days at 2°C caused opposite changes in the levels of these senescence parameters (measured at constant temperature). It was concluded that cold storage does not simply lead to a slow rate of senescence, but has other effects on cell properties.