干旱胁迫对丹参幼苗气体交换特征和保护酶活性的影响

以大叶型丹参(SA)和小叶型丹参(SI)为材料,设置了对照正常供水(CK)、轻度干旱胁迫(LD)、中度干旱胁迫(MD)、重度干旱胁迫(SD)4个处理,研究了不同程度干旱胁迫对丹参叶片气体交换特征与保护酶的影响.结果显示:(1)干旱胁迫下2个丹参品种叶片的净光合速率(Pn)、蒸腾速率(T.)、气孔导度(Gs)都有不同程度...     

氯化胆碱对干旱胁迫下玉米幼苗叶片膜结构保护机制的研究

用300 m g/L氯化胆碱(CC)浸种与叶面喷施相结合作预处理,然后用15% PEG- 6000 模拟干旱胁迫。发现CC在干旱条件下可减缓CAT、POD活力和类胡罗卜素含量的降低, 特别是改变了SOD活力在干旱胁迫下通常呈波浪式变化的规律, 使其在实验条件下一直呈上升趋势。这些可能是膜结构得到保护, 从而使膜脂过氧化产物MDA 产生及细胞电解质渗漏都明显减少的主要原因。     

邻羟基苯甲酸对干旱胁迫下杉木幼苗保护酶的影响

为研究干旱胁迫下杉木自毒物质邻羟基苯甲酸(SA)对杉木幼苗的毒害作用,采用不同浓度的聚乙二醇(PEG-6000)模拟干旱处理,通过水培方法研究干旱胁迫下不同浓度杉木自毒物质邻羟基苯甲酸(SA)对杉木幼苗保护酶的影响.结果表明:在轻度(-0.3MPa)、中度(-0.5MPa)干旱胁迫下,随SA浓度增加超氧化物歧化酶(SOD)活性先降后升再下降,但重度(-0.7MPa)干旱胁迫下,SOD活性直线下降;过氧化物酶(POD)活性则表现为在轻度干旱胁迫下先降后升,中度和重度干旱胁迫下总体呈下降趋势.     

干旱胁迫对小麦叶片核糖核酸酶活力及合成的影响

干旱协迫下，抗旱（陕合６号）与干旱敏感（郑引１号）小麦品种叶片中的核糖核酸酶活性均有所增加，增加幅度与其相对含水量变化呈显著负相关。１４Ｃ－Ｌｅｕ掺入后，样品粗提液经ＰＡＧＥ分离并染色，发现干旱处理叶片的两个低分子女（１２ｋＤ、１７ｋＤ）具ＲＮａｓｅ活性的蛋白质的放射性掺入总量低于对照，但占总蛋白的放射性比例高子对照，证明干旱胁迫下存在ＲＮａｓｅ的从头合成（ｄｅｎｏｖｏｓｙｎｔｈｓｉｓ）。讨论了胁迫下ＲＮａｓｅ活性增加的原因。     

冬季干旱胁迫下黄土高原三种常绿树种叶片渗透调节物质变化研究

用盆栽试验研究冬季在水分胁迫条件下三种常绿树木渗透调节物质的变化特征。研究结果表明：在冬季适宜土壤水分（田间持水量的70％）和严重干旱（田间持水量的30％）2种土壤水分条件下，侧柏、女贞和小蜡渗透调节物质变化呈现出一定的变化规律。在相同生长期内渗透调节物质含量水分胁迫（30％）高于正常供水（70％）。侧柏与女贞和小蜡相比，叶片水势低，可溶性糖和K^＋含量较高，脯氨酸含量差异不显著。渗透调节物质含量在12月和1月最高。运用水势、可溶性糖含量和K^＋含量评价三个树种对干旱和低温适应强弱的顺序依次为侧柏，女贞和小蜡。黄土高原造林过程中可根据生态环境条件和实际用途进行树种选择。     

干旱胁迫下2种香蕉幼苗叶片和根的主要渗透调节物质的变化

本文研究了不同干旱胁迫下抗旱性不同的帝王蕉和粉蕉幼苗叶片和根系的可溶性蛋白质和可溶性糖主要渗透调节物质的含量变化。结果表明：2种香蕉幼苗叶片可溶性蛋白质和可溶性糖含量随着干旱胁迫程度的增加而显著增多;根系可溶性蛋白质和可溶性糖含量并未持续上升,而是重度胁迫低于中度胁迫,但仍高于对照和轻度胁迫。干旱胁迫后,除帝王蕉根系可溶性糖含量外,帝王蕉根系可溶性蛋白质、粉蕉根系可溶性蛋白质和可溶性糖含量在3个胁迫程度下增加幅度均大于叶片增加幅度,且粉蕉较帝王蕉更能适应干旱胁迫环境。本文将为香蕉抗旱品种选育和栽培提供一定的理论依据和实践意义。     

不同倍性菘蓝对干旱胁迫的耐受能力及保护性酶的响应机制

为了比较不同倍性菘蓝对干旱胁迫的耐受能力及其体内保护性酶的响应机制,在MS培养基中加入不同浓度的甘露醇模拟干旱胁迫处理,观测不同倍性菘蓝种子的萌发和幼苗生长状况,测定幼苗中丙二醛及脯氨酸含量,同时对其地上部分保护性酶SOD、POD和CAT进行测定。种子萌发、幼苗生长以及丙二醛和脯氨酸含量的测定结果均表明,四倍体菘蓝较二倍体菘蓝对干旱胁迫的耐受能力强。对其体内保护性酶的研究结果表明,随着甘露醇浓度的增加二倍体和四倍体菘蓝中SOD、POD和CAT三种保护性酶均呈现先增加后降低的趋势,各甘露醇浓度下四倍体中的SOD、POD和CAT三种保护性酶活性均高于二倍体,说明在干旱胁迫下四倍体菘蓝对活性氧的清除能力高于二倍体菘蓝,部分解释了四倍体菘蓝较二倍体菘蓝对干旱胁迫的耐受能力强。     

干旱逆境下不同品种水稻叶片有机渗透调节物质变化研究

通过聚乙二醇 (PEG)模拟水稻短期干旱胁迫研究表明 ,干旱胁迫条件下 4个水、陆稻品种叶片中可溶性有机渗透调节物质如游离氨基酸总量 (TFA)、脯氨酸 (Pro)和可溶性糖 (SS)含量及Pro/TFA比值变化上具有种间一致性 ,均呈显著上升趋势 ,且巴西陆稻的变化较为明显 ;可溶性渗透调节物质适宜作为水稻抗旱能力筛选的参考指标。     

Ce对UV- B胁迫下油菜幼苗光合与保护酶的影响

UV—B辐射增强对植物生理、生化和生长发育的影响，国内外已有大量报道，这为科学评价UV—B环境植物学效应奠定了基础。与此交臂的是，稀土（RE）用于酸雨、重金属、臭氧及农药污染防治等方面的工作也已初见端倪。本文初步考察了RE对UV—B辐射胁迫下植物光合与保护酶功能的影响，旨在为RE农用拓展及环境污染防治提供依据。     

干旱胁迫对紫金牛叶片碳氮代谢的影响

以盆栽紫金牛2年生扦插苗为试验材料,以常规灌水为对照,研究了轻度干旱、中度干旱、重度干旱处理对紫金牛叶片碳氮代谢相关物质含量及酶活性的影响。结果表明,随着处理时间的延长和干旱胁迫程度的加剧,紫金牛叶片中的可溶性糖、可溶性蛋白质和游离氨基酸含量逐渐升高,淀粉和叶绿素含量显著降低,胁迫程度越严重,变化幅度越大。轻度干旱胁迫下紫金牛叶片的酸性转化酶(AI)、中性转化酶(NI)、蔗糖磷酸合成酶(SPS)、蔗糖合成酶(SS)活性与对照相比均没有显著变化,而中度和重度干旱胁迫处理的AI、NI、SPS、SS活性显著降低。紫金牛叶片的硝酸还原酶(NR)和谷氨酰胺合成酶(GS)活性随着干旱胁迫程度的加重均呈先上升后下降的变化趋势,而谷丙转氨酶(GPT)活性呈上升的变化趋势。由此可知,紫金牛可通过增加渗透调节物质的含量来增强其耐旱性,具有较强的抗旱能力,轻度和中度干旱条件下紫金牛能够在一定时间范围内有效地抵御严重干旱所造成的胁迫。     

干旱胁迫下硅对番茄叶片光合荧光特性的影响

【目的】研究干旱胁迫下不同硅水平对水培番茄(Lycopersicon esculentum)叶片气体交换参数和叶绿素荧光参数的影响,为番茄生产合理增施硅肥提供理论依据。【方法】以“金棚1号”番茄为试验材料,采用Hoagland营养液进行了水培试验。聚乙二醇(PEG-6000)模拟干旱条件进行预处理,筛选出适于本研究的PEG-6000干旱胁迫水平为1%; 之后以Na2SiO3·9H2O为硅源,以不添加PEG-6000和Na2SiO3·9H2O的Hoagland营养液为CK0,研究了1% PEG-6000模拟干旱胁迫条件下,Hoagland营养液中分别添加Na2SiO3·9H2O 0(CK)、 0.6(T1)、 1.2(T2)、 1.8(T3)mmol/L,对番茄幼苗叶片色素含量、 水分状况、 气体交换参数及叶绿素荧光参数的影响。【结果】随干旱胁迫时间延长,不同硅水平处理的番茄叶片相对含水量(RWC)、 光合色素含量、 净光合速率(Pn)、 气孔导度(Gs)、 最大光化学效率(Fv/Fm)、 实际光化学效率(ΦPSⅡ)、 光化学淬灭系数(qP)等均持续下降,非光化学淬灭系数(NPQ)逐渐上升,气孔限制值(Ls)先升高后降低,细胞间隙二氧化碳浓度(Ci)先降低后升高,但不同硅水平处理番茄叶片相关参数降低或升高的幅度存在显著差异。在处理第12 d时,0.6、 1.2 mmol/L硅水平处理的番茄叶片RWC较不施硅对照(CK)分别提高18.03%、 30.25%,叶绿素含量分别增加64.56%、 88.24%,Pn分别增加48.78%、 131.71%,ΦPSⅡ分别增加31.68%、 62.70%,qP分别增加18.92%、 40.54%,NPQ则分别降低9.54%、 13.35%。但1.8 mmol/L的硅水平处理12 d时相关参数除NPQ外,均较对照(CK)显著降低,如叶片RWC、 叶绿素含量、 Pn、 ΦPSⅡ和qP分别降低了17.53%、 21.79%、 21.95%、 10.16% 和5.41%。【结论】 1% PEG-6000模拟干旱胁迫条件下,Hoagland营养液添加1.2 mmol/L Na2SiO3·9H2O显著改善了番茄叶片的水分状况,降低了光合色素的降解,提高了叶片色素光化学效率,减轻了光抑制程度,有利于维持较高的光合速率。     

Oxidant related biochemical traits are significant indices in triticale grain yield under drought stress condition

Two separate experiments, one as drought stress conditions and the other one as the normal irrigation conditions based on randomized complete block design with three replications were implemented to examine 20 triticale (Triticoseclae wittamack X) genotypes of which 19 genotypes have recently been generated by crossing different parent lines and the other one was Javaniloo, a common cultivar. Based on the results of different statistical techniques and comparing relationships among traits for normal irrigation and stress condition, enzymatic antioxidant could be used as criteria for screening tolerant genotypes of triticale. On the other hand, it is pointed out that superoxide dismutase are the most important criteria to achieve higher tolerant genotypes through indirect selection. Furthermore, hydrogen peroxide and malondialdehyde content having high relationship with rain yield are also the different possible criteria for screening triticale genotypes for water stress conditions in which genotypes with lower content of these traits could be screened.     

甜菜碱对干旱胁迫下棉花幼苗生理特性的影响

以新疆广泛种植的棉花品种新陆早18号为试材,通过测定棉花幼苗体内脯氨酸、可溶性糖和丙二醛（MDA）的含量及抗氧化酶包括超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和过氧化物酶（POD）的活性,研究叶面喷施不同浓度甜菜碱（Glycine betaine,GB）对干旱胁迫下棉花幼苗生理特性的影响。结果表明,干旱胁迫下,与对照相比,脯氨酸、可溶性糖、MDA含量及SOD和POD活性都显著提高,喷施甜菜碱后促进脯氨酸和可溶性糖含量进一步提高,酶活也显著升高,同时有效抑制了丙二醛含量的增加,CAT活性受干旱胁迫及甜菜碱的影响较小。研究表明喷施低浓度甜菜碱在一定程度上可以缓解干旱胁迫对棉花幼苗的伤害。     

利用高光谱估测干旱胁迫下接菌根菌大豆叶绿素含量

该研究旨在利用高光谱遥感动态监测干旱胁迫下接种菌根植物生长状况,为菌根技术在旱区农业中的推广提供一定的理论基础。以盆栽大豆为对象,在不同接种丛枝菌根时期采用高光谱遥感技术监测不同干旱胁迫下接菌和不接菌处理大豆叶片的叶绿素含量变化,对比分析了3个水分梯度下及同一水分梯度下接菌和不接菌处理的大豆地上部分干质量、叶绿素含量和叶片光谱在可见光和近红外区域的响应特征差异,建立了大豆叶绿素含量与多个光谱变量的估测模型。研究结果表明:接菌第45天和第64天,同一水分梯度下接菌大豆地上部分干质量优于不接菌处理,且其叶绿素含量也高于不接菌,这些差异在叶片光谱曲线特征中同样得以反映,接种菌根在一定程度上可以缓解干旱胁迫对植物生长的影响;基于多元线性逐步回归方法建立的一阶微分模型能较准确地估测干旱胁迫下接菌大豆的叶绿素含量,其模型决定系数和预测检验决定系数分别为0.90和0.84,具有较高的精度和良好的预测能力。     

PEG-induced drought stress effects on soybean germination parameters

Abstract

As a result of global climatic changes, water deficiency is threatening food production for the increasing population worldwide, especially drought-sensitive crops, to which soybean belongs, by suppressing yield potentials. Drought stress can inhibit sown seeds’ germination and manipulate germination parameters. A controlled, two-stage experiment was conducted to investigate the effects of drought stress, induced by PEG (polyethylene glycol), on some germination parameters of two soybean cultivars; ‘ES Mentor’ and ‘Pedro’, in Debrecen, Hungary in 2018. At the first stage, 5 PEG concentrations; 10, 15, 20, 25, and 30%, besides control (0% PEG), were applied to each cultivar in 3 replicates. Results showed that both cultivars could not germinate when 25 and 30% of PEG were applied. Significant differences among PEG concentrations, between cultivars and their interaction were recorded. Based on these results, the second stage consisted of 6 PEG concentrations; 2.5, 5, 7.5, 10, 12.5 and 15% (besides control), also in three replicates. For both cultivars, germination ratio (GR) and root elongation (RE) decreased as the PEG concentration increased. Both germination energy (GE) and ultimate germination (UG) decreased, whereas mean period of altimate germination (MPUG) and percentage inhibition increased with increasing water stress. ‘ES Mentor’ could maintain higher (GR) than ‘Pedro’ under all PEG concentrations except 15%, whereas (RE) was lower under all concentrations. It was concluded that ‘ES Mentor’ can germinate better under different water deficiency levels; however, germinated seeds of ‘Pedro’ can tolerate relative water stress better, as the roots could elongate deeper searching for available water.     

干旱胁迫条件下加工番茄对喷施甜菜碱的生理响应

以新疆广泛种植的加工番茄屯河8号为材料,通过盆栽和田间试验,测定了加工番茄叶片中叶绿素、可溶性蛋白、脯氨酸、可溶性糖和丙二醛含量以及抗氧化酶 [超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、过氧化物酶（POD）] 活性和加工番茄产量,研究了干旱胁迫下加工番茄对叶面喷施不同浓度甜菜碱的生理响应。结果表明,干旱胁迫下喷施低浓度甜菜碱对加工番茄抵御干旱有一定的作用。干旱胁迫下喷施甜菜碱后,有效抑制了叶绿素和可溶性蛋白含量的下降,协同增加脯氨酸和可溶性糖的含量,抗氧化酶活性也显著增强,膜脂过氧化程度减弱即丙二醛含量下降,田间试验各生理指标的含量变化与盆栽结果相类似,干旱胁迫下喷施甜菜碱促进了加工番茄产量的增加。     

氯化钾对干旱胁迫下马铃薯根系生理及形态的影响

以马铃薯品种"大西洋"为材料,研究了6个钾肥施用量(以K2O计):CK(0 g/株)、C1(1.2 g/株)、C2(2.4 g/株)、C3(3.6 g/株)、C4(4.8 g/株)、C5(6.0 g/株)对2个干旱胁迫程度[轻度干旱胁迫("轻旱,D1")、中度干旱胁迫("中旱,D2")]和正常灌溉下马铃薯根系生理和形态发育特征的影响。试验结果显示,根系生理方面,干旱胁迫下增施钾肥可不同程度地增强马铃薯根系抗旱性。各处理马铃薯根系含水量、地下部分干重、根冠比表现为D1D2,除根冠比在各施肥处理间无显著差异外(P﹥0.05),以上指标均以C3处理效果最为显著(P0.05)。各处理马铃薯根系超氧阴离子产生速率、丙二醛含量表现为D2D1,且C2处理下降幅显著(P0.05)。根系活力、过氧化氢酶和超氧化物歧化酶活性分别在C1、C2、C3处理及以下表现为D2D1,此后相反;过氧化物酶活性整体上表现出D2D1的变化趋势。以上指标在C2处理下效果显著(P0.05)。根系形态方面,整体上看,钾肥作用下马铃薯总根长、根直径、根表面积、根体积增加,根尖数减少。各处理下马铃薯根直径、根表面积、根体积表现为D1D2,总根长、根尖数分别在C2、C3处理及以下表现为D2D1,此后相反;干旱胁迫下根系各形态指标对钾肥增施量的响应较为复杂,整体表现为"轻旱高钾促进,中旱低钾促进"的变化趋势。产量方面,干旱胁迫导致薯重降低,增施钾肥提高了马铃薯单株总薯重,以C3处理增产效果最显著(P0.05)。综合以上分析认为,钾肥的施入应充分考虑当地土壤水分状况并依此制定合理的施入量,这样才有利于马铃薯根系抗性的提高和形态的建成。     

Evaluation of bread wheat (Triticum aestivum L.) genotypes for yield and related traits under drought stress conditions

ABSTRACT

Drought is a major factor threatening crop production worldwide. Developing wheat varieties that are adapted to drought prone environments is a sustainable strategy to improve wheat production and productivity. The aim of this study was to evaluate and select bread wheat genotypes for yield and yield components, and for stability under drought stress and non-stress conditions. One hundred and twenty genotypes were evaluated at five test sites in the 2018/19 cropping season using a 10 x 12 alpha lattice design with two replicates. The level of drought stress was imposed using different sowing dates (early planting representing non-stressed, while late planting as drought stressed conditions) following the onset of the main rain at each site. Grain yield and yield components were recorded, and drought indices were calculated for each genotype. Among the drought tolerance indices, GMP, MP, HM, STI and YI were found to be the most suitable for predicting drought tolerance because they had significant and positive correlations with yield under drought stress and non-stress conditions. Rank sum analysis identified the most drought tolerant genotypes as ‘YS-34', ‘YS-85' and ‘YS-82’. The selected wheat genotypes are useful genetic resources for future drought tolerance breeding programmes in Ethiopia or similar agro-ecologies.     

Responses of cucumber (Cucumissativus L.) to ozonated water under varying drought stress intensities

This study explores the effect of drought stress and ozone on cucumber. A factorial experiment with complete randomized design was carried out in a greenhouse. Experimental treatments were drought stress, including three levels 100% (control), 80%, and 60% of the field capacity (FC) and three ozone concentrations of 0, 0.5, and 1 ppm. The drought stress (80% and 60% of the FC) significantly reduced fruit length, weight, and yield, leaf area, and number of fruits. Across the levels of drought stress, the statistical analysis showed significant increments in the fruit weight with the increasing in the ozone concentrations. An enhancement in the total suspended solids values was obtained with the increase in the drought stress level. The height, dry, and fresh weights of plant decreased with the increase in the drought stress level. The highest leaf area, dry, and fresh weights were observed in the 0.5 ppm ozone and 100% FC.