不同耐盐性小麦胚芽鞘伸长对NaCI胁迫的响应

以100mmolL^-1NaCI处理耐盐小麦品种德抗961和盐敏感品种鲁麦15各2d，测定其胚芽鞘相对伸长速率及渗透调节能力。结果表明，NaCl处理抑制小麦胚芽鞘的伸长，其相对伸长速率最大值减小，生长最快的时间推后，但胚芽鞘最终长度没有改变；NaCI胁迫使小麦胚芽鞘渗透势下降，德抗961渗透调节能力强于鲁麦15；NaCl胁迫使小麦胚芽鞘Na^＋、脯氨酸、总可溶性糖含量明显增加，德抗961增加幅度大于鲁麦15；NaCl胁迫下，德抗961胚芽鞘伸长明显好于鲁麦15，其具有较强渗透调节能力是原因之。因此，一定浓度NaCl处理下小麦胚芽鞘的长度可作为耐盐筛选的有用指标。     

盐胁迫下不同小麦品种芽鞘生长的研究

室内模拟盐胁迫条件,对耐盐性不同的4个品种萌发期的芽鞘长度进行测定,结果表明,在不同浓度的盐胁迫下,耐盐性不同的小麦品种芽鞘长度差异明显,且耐盐性强的品种明显高于不耐盐的品种;通过测定不同部位的渗透调节能力后发现,盐胁迫下耐盐品种不同部位的渗透调节能力均高于不耐盐品种,且芽鞘的调节能力最高.     

利用SOM聚类分析及主成分分析方法鉴定小麦品种萌发期耐盐性

为了研究不同小麦品种萌发期的耐盐性,为小麦萌发期耐盐性鉴定提供快速、准确的鉴定方法和理论依据。本研究以40个冬小麦品种为试验材料,通过主成分分析法(PCA)与神经网络自组织映射(SOM)聚类分析法,研究盐胁迫对40个小麦品种萌发期各项形态指标的影响。主成分分析法结果表明,发芽势、发芽率、最长根长、第一片叶长及胚芽鞘长在PCA下载荷量最大;根据SOM聚类分析结果,‘德抗961’等4个小麦品种属于高度耐盐品种,‘济麦22’等14个小麦品种属于耐盐性品种,‘济麦20’等16个品种属于中等耐盐性品种,‘鲁麦21’等6个小麦品种属于盐敏感性品种。发芽势、发芽率、最长根长、第一片叶长、胚芽鞘长能够作为萌发期小麦耐盐性筛选的主要评价指标,并且结合主成分、SOM聚类分析方法进行小麦萌发期耐盐性鉴定更为科学、方便。     

盐胁迫及其与La3+对不同耐盐性水稻根中抗氧化酶及质膜H+-ATPase的影响

用盐敏感的武运粳8号和强耐盐的韭菜青两个粳稻品种，比较了盐胁迫条件下根中抗氧化酶类和质膜H⁺-ATPase活性的变化以及La³⁺对其变化的影响。结果表明，两个品种根中SOD和APX活性无显著区别，但耐盐品种的CAT和POD活性强于盐敏感品种。盐胁迫不同程度地提高了两者抗氧化酶活性。La³⁺对其影响最显著的差异出现在高盐条件下（200~300 mmol L^-1 NaCl），对耐盐品种添加La³⁺可以提高上述4种酶的活力，而对盐敏感品种，La³⁺的作用不明显。对盐敏感品种，盐胁迫导致其质膜H⁺-ATPase活性持续下降，添加La³⁺明显提高其H⁺-ATPase活性，而对耐盐品种，盐胁迫导致其质膜H⁺-ATPase活性呈现先降后升的趋势，La³⁺对其活性影响不大。进一步分析表明，上述H⁺-ATPase活性变化及La³⁺对其影响均发生在转录水平上。据此推测，以上2个品种可能具有完全不同的盐胁迫响应机制。     

土壤水分胁迫下小麦叶片渗透调节与光合作用

在土壤水分胁迫过程中,抗旱性强的小麦品种昌乐5号、北农2号与抗旱性弱的品种济南13,鲁麦5号相比,渗透调节能力高0.41Mpa~0.604Mpa;相对含水量少降7%~8%;叶片水势少降0.40Mpa~0.41MPa。水分胁迫使叶片光合能力下降,抗早性强的品种与抗早性弱的品种相比,其下降的平均百分数为;光合速率前者比后者少降17%~22%;气孔导度     

盐胁迫下不同K~+吸收抑制剂对小麦根系K~+/Na~+比和质膜相关蛋白活性的影响

为了研究不同K~+吸收途径在小麦耐盐机理中的作用,以小麦耐盐品种沧6005(C6005)和敏感品种矮抗58(AK58)为材料,通过K~+吸收相关抑制剂和NaCl对幼苗进行根系处理,测定并分析了根系K~+、Na~+含量、比值和质膜K~+转运相关蛋白活性的变化。结果表明:与正常条件生长小麦相比,250 mmol/L NaCl处理7 d后,2种耐盐性不同的小麦根系中的K~+/Na~+比明显降低,同时与敏感品种相比,耐盐品种能保持较高的K~+/Na~+比;NaCl胁迫下,通过3种抑制剂处理对K~+含量及K~+/Na~+比值的影响发现,与钾离子通道和非选择性阳离子通道途径相比,小麦根系K~+吸收主要通过钾载体途径;当该途径被抑制时,沧6005的K~+/Na~+比下降幅度明显高于矮抗58,表明耐盐品种更依赖该途径;NaCl胁迫下,钾载体途径被抑制时,小麦根系质膜质子泵H~+-ATPase和H~+-PPase活性明显降低,且沧6005降低幅度相对更大;NaCl胁迫下,钾载体抑制剂处理,对沧6005质膜K~+/H~+转运蛋白的抑制作用明显强于矮抗58,进一步证明上述结果。研究表明,盐胁迫下小麦主要通过钾载体途径吸收K~+,耐盐品种沧6005对钾转运载体的依赖程度更高;高NaCl环境中,细胞质膜质子泵活性和钾载体活性的提高对于维持K~+/Na~+比具有重要作用。为深入解析小麦耐盐机理提供了理论依据。     

76份冬小麦品种（系）苗期耐旱性鉴定筛选研究

为了解不同冬小麦品种（系）的耐旱性,掌握冬小麦在轻度干旱胁迫条件下的胚芽鞘长度变化规律,缩短抗旱小麦品种筛选周期,以76份冬小麦品种（系）为试验材料,采用聚乙二醇（PEG-6000）模拟田间干旱胁迫,并对不同材料的胚芽鞘长度进行调查,运用聚类分析方法按遗传距离对所有材料进行分类。结果表明：不同品种（系）种子之间、同一品种（系）种子水处理与PEG处理之间胚芽鞘的长度均存在梯度的差异;加入聚乙二醇（PEG-6000）后,种子生长受到胁迫,胚芽鞘的生长速度比对照处理的生长速度减慢,胚芽鞘的伸长长度比对照处理的胚芽鞘长度短;经过PEG处理后的种子胚芽鞘长度明显低于在水中生长的种子。筛选出经PEG处理胚芽鞘长度高于对照洛旱7号的品种开麦1606和济麦22。与对照品种周麦36相比,胚芽鞘更长的品种有38个,胚芽鞘长度增幅1.39%～53.47%。根据胚芽鞘长度的变化,将76份小麦材料分为8类,类群IV胚芽鞘长度最长,可作为抗旱性小麦品种（系）。该结果可为抗旱品种的筛选和新品种选育及抗旱机制研究提供参考和基础材料。     

亚精胺浸种对玉米胚芽鞘抗渗透胁迫能力的影响

亚精胺(spermidine:Spd)浸种后,研究了渗透胁迫下,玉米品种农大108(抗旱性较强)和掖单13(抗旱性较弱)胚芽鞘的长度、相对含水量(relative water content:RWC)、相对电解质渗漏率(relative electrolyte leakage:REL)和鞘内Spd含量的变化.渗透胁迫第4天,抗旱性弱的掖单13玉米胚芽鞘的REL的上升幅度明显大于抗旱性强的农大108,其鞘内Spd含量的升幅则明显小于农大108;而农大108胚芽鞘的长度和RWC的下降幅度明显小于掖单13.Spd浸种处理,则明显抑制掖单13在胁迫条件下其胚芽鞘长度、RWC的下降和REL的增加,促进鞘内Spd含量的增加.这些结果表明,Spd浸种通过提高渗透胁迫下玉米(特别是抗旱性较弱的品种)胚芽鞘中Spd的水平,从而增强玉米胚芽鞘的抗渗透胁迫能力,促进其生长.     

甜菜碱浸种对棉苗耐盐性的影响

选用目前生产上主推的抗虫棉品种99B和鲁棉研28, 用400 mg mL^-1甜菜碱浸种, 及用含或不含0.4% NaCl的Hoagland营养液盆栽培养, 以研究其对棉花幼苗生理特性的影响。结果表明, 无论在盐胁迫还是非盐胁迫条件下, 甜菜碱浸种对棉花幼苗生理特性均有显著影响, 可促进棉花苗期叶片叶绿素合成, 降低叶绿素的a/b值, 增加叶绿素荧光动力学参数F_v/F_m、F_v/F_o、光合电子传递速率(ETR)和光系统Ⅱ的实际量子效率(Φ_PSⅡ)值, 从而提高棉花苗期叶片的光合能力; 并提高棉花苗期叶片和茎秆可溶性糖含量及叶片脯氨酸含量, 降低棉花苗期子叶相对电导率, 提高棉花苗期渗透调节能力, 缓解盐胁迫伤害; 同时还增强棉苗子叶硝酸还原酶活性, 促进棉苗氮素代谢。两种品种对甜菜碱的反应趋势一致, 但99B比鲁棉研28更敏感一些。     

水分胁迫条件下不同肥水类型小麦抗旱特性的研究

为了提高小麦抗旱性,本试验选用6个肥水类型不同的小麦品种,在聚乙二醇-6000(PEG-6000)水分胁迫条件下考察了不同小麦品种种子的萌发状况和小麦幼苗的生理生化变化,并在防雨旱棚池栽条件下对品种的抗旱性进行了鉴定。结果表明,不同肥水类型小麦品种随着水分胁迫时间的延长胚芽鞘长度、相对发芽率和硝酸还原酶活性均降低,可溶性糖含量和丙二醛含量均升高,根系活力呈现先略微升高再下降的趋势。与水浇地品种相比,旱地品种青麦6号、济旱5034和鲁麦21的胚芽鞘长度较长,相对发芽率、硝酸还原酶活性和根系活力相对较高且下降缓慢,可溶性糖含量较高且随胁迫时间延长增加的幅度大,丙二醛含量积累的速度较为缓慢。其中,胚芽鞘长度、相对发芽率、硝酸还原酶活性和根系活力与抗旱性鉴定指标抗旱指数存在极显著相关性,可以作为小麦抗旱性鉴定的早期指标。     

Jasmonic Acid Differentially Affects Growth, Ion Uptake and Abscisic Acid Concentration in Salt-tolerant and Salt-sensitive Rice Cultivars

Phytohormones play critical roles in regulating plant responses to stress. Here, we investigated the effects of salt stress and stress recovery by applying jasmonate to the two different rice (Oryza sativa L.) cultivars Dongjinchalbyeo (DJC, salt-tolerant) and Dongjinbyeo (DJ, salt-sensitive). Salt stress remarkably decreased the root length of plants even at low NaCl concentration (20 mm ). Salt stress led to a sharp increase in the concentrations of abscisic acid (ABA) in 20 and 40 mm NaCl, when compared with the control values. The concentrations of ABA in the salt-tolerant cultivar DJC plants progressively increased with increasing NaCl levels, whereas in the salt-sensitive cultivar DJ, they sharply decreased in all three parts of rice plants at 80 mm NaCl treatment. The decrease of jasmonic acid (JA) concentrations in salt-tolerant cultivar DJC was lesser than in the salt-sensitive cultivar DJ plants in the shoot. Post-application in the stressed plants with 30 μm JA at 24 and 48 h after NaCl treatment, recovered salt inhibition on dry mass production more effectively than application of JA at 48 and 24 h before salt stress, and during salt stress simultaneously. The uptake of Na decreased especially in the salt-sensitive cultivar DJ plants, whereas there was an increase in Ca and Mg levels and slight increase of K by JA application. Leaf water potential, leaf photosynthetic rate, and maximum quantum yield of photosystem II (PSII) also remarkably recovered when 30 μm JA was applied 24 h after the salt stress compared with the 40 mm NaCl-treated plants. These results clearly indicate that post-application with exogenous JA can ameliorate salt-stressed rice seedlings, especially the salt-sensitive cultivar rather than the salt-tolerant cultivar. This may change the balance of other endogenous plant hormones.     

盐胁迫及La3+对不同耐盐性水稻根中抗氧化酶及质膜H+-ATPase的影响

用盐敏感的武运粳8号和强耐盐的韭菜青两个粳稻品种,比较了盐胁迫条件下根中抗氧化酶类和质膜H＋-ATPase活性的变化以及La^3＋对其变化的影响。结果表明,两个品种根中SOD和APX活性无显著区别,但耐盐品种的CAT和POD活性强于盐敏感品种。盐胁迫不同程度地提高了两者抗氧化酶活性。La^3＋对其影响最显著的差异出现在高盐条件下（200-300mmolL^-1NaCl）,对耐盐品种添加La^3＋可以提高上述4种酶的活力,而对盐敏感品种,La^3＋的作用不明显。对盐敏感品种,盐胁迫导致其质膜H＋-ATPase活性持续下降,添加La^3＋明显提高其H＋-ATPase活性,而对耐盐品种,盐胁迫导致其质膜H＋-ATPase活性呈现先降后升的趋势,La^3＋对其活性影响不大。进一步分析表明,上述H＋-ATPase活性变化及La^3＋对其影响均发生在转录水平上。据此推测,以上2个品种可能具有完全不同的盐胁迫响应机制。     

胚芽鞘长度作为冬小麦抗旱性鉴定指标的研究

２０％ＰＥＧ－６０００（ｗ／ｖ）作渗透介质，室内模拟干旱条件，对７个旱性不同的冬小麦品种（系）萌发期的芽鞘长、芽长、根长进行了测定。结果表明：渗透胁迫下，抗旱性不同的冬小麦品种（系）芽鞘长、芽长、根长差异显著，以芽鞘长与抗旱性符合最好。芽鞘长与渗透调节能力关系密切。根据实验结果，建立了“冬小麦抗旱性鉴定筛选程序”。用此程序对１１ ３个冬小麦品种（系）进行了抗旱鉴定和系统聚类分析，效果良好。     

渗透胁迫和盐胁迫对荞麦硝酸还原酶及亚硝酸还原酶活性的影响

以盐敏感荞麦品种TQ-0808和耐盐荞麦品种川荞1号为试验材料,采用NaCl和等渗PEG-6000处理,研究渗透胁迫和盐胁迫对不同耐盐性荞麦品种硝酸还原酶(NR)及亚硝酸还原酶(NiR)活性的影响。结果表明,高浓度盐胁迫下盐敏感荞麦品种叶片NR及NiR活性显著降低,而耐盐荞麦品种降低幅度相对较小,且高浓度盐胁迫下盐敏感荞麦品种叶片NR及NiR活性的降低幅度明显大于渗透胁迫的,说明Na⁺毒害效应发挥了主要作用。另外,两个荞麦品种叶片NR活性高低与其叶片硝酸盐含量呈正相关。     

大豆苗期耐盐性的简便鉴定方法

盐胁迫是影响大豆产量的重要非生物胁迫因素,筛选耐盐种质资源对培育耐盐大豆品种具有重要的意义。本研究利用4个耐盐品种和4个盐敏感品种进行苗期耐盐性鉴定,以蛭石为培养基质,在大豆真叶展开时,分别用100、200和250 mmol L^–1的NaCl溶液处理,每2 d浇一次盐溶液,每天测定大豆真叶SPAD值。盐处理8 d后,分别取各品种的根、茎、叶,用原子吸收光谱仪测定其Na⁺含量。结果表明,用200 mmol L^–1 NaCl处理的耐盐品种和盐敏感品种表型差异明显,但叶片Na⁺含量差异不显著;用250 mmol L^–1 NaCl处理后,表型差异明显且叶片Na⁺含量差异显著。200 mmol L^–1和250 mmol L^–1 NaCl处理下叶片失绿明显,盐敏感品种叶片积累的Na⁺含量与SPAD值极显著负相关。本研究建立了一种以蛭石为基质,用200 mmol L^–1或250 mmol L^–1 NaCl处理,8 d即可进行大豆苗期耐盐性鉴定的简便方法,为大豆种质资源苗期耐盐性的大规模鉴定及耐盐品种选择和耐盐机理的研究提供了方法。     

Varietal Differences of Wheat and Triticale to Water Stress

Six wheat ( Triticurn aestivum L.) and ten triticale (x Triticosecale Wittmack) cultivars were screened for water stress tolerance during germination and seedling stages in the laboratory and growth chamber, respectively. Germinating seeds and hydroponically-grown seedlings were subjected to osmotic stresses of –0.3 and –0.6 MPa using polyethylene glycol M. W. 8000. Both species and cultivar differences were found among the tested genotypes for all the parameters analyzed in both germination and seedling tests. Germination stress index was lower for seed exposed to -0.6 MPa than for -0.3 MPa osmotic stress. A significant relationship was found among plant height, fresh weight and dry weight stress indices evaluated during the seedling test. The cultivars that grew taller under stress conditions had greater dry matter accumulation, as well as higher germination and water uptake stress indices indicating the reliability of height to predict cultivar performance under such conditions. The cultivars Stacy (wheat) and Eu 14/15 (triticale) had higher dry matter accumulation, higher water uptake and leaf water potential, greater height and better germination under stress conditions than the other cultivars tested. Conversely, the cultivars GA 781014 (wheat) and Am 4147 (triticale) performed poorly with respect to all the parameters analyzed. Based on results from germination and seedling tests, the cultivars Stacy and Eu 14/15 were selected for more stress studies in the greenhouse and field.     

PEG胁迫下春小麦萌发期抗旱指标的遗传力

为探索干旱胁迫对春小麦萌发期生长的影响,筛选春小麦萌发期抗旱性指标。以宁夏灌区和雨养区的2种粒色（红皮和白皮）40份春小麦的抗旱品系为试验材料,研究PEG-6000模拟干旱胁迫对胚根长、胚根数、胚芽鞘长和一叶长的影响。利用广义遗传力分析法,筛选春小麦萌发期抗旱性指标。胚根长的广义遗传力最高,均大于0.55,遗传力的控制程度稳定。雨养区的红粒种子胚根长的遗传力高达0.95;雨养区的红粒种子的胚芽鞘长的广义遗传力最高,达0.94,但其遗传力控制程度不稳定,最低遗传力仅为0.06;胚根数和一叶长的遗传力很低,且控制程度极不稳定。春小麦萌发期胚根长的广义遗传力最高,控制程度稳定。其次是胚芽鞘长,但其遗传力的控制程度不稳定。胚根长可作为春小麦萌发期的抗旱指标鉴定抗旱材料,以胚芽鞘的长度为参考值。     

水稻萌发和幼苗生长对外源物质调节的响应

为了明确水稻萌发期种子简易活力指数、胚根及幼苗株高等形态指标及对外源NaCl、IAA、CaCl₂调节的响应,本试验以盐敏感品种和耐盐水稻品种为试材,用发芽皿试验法,单因素LSD多重比较分析数据。结果表明,在0.1 mol/L NaCl胁迫下,与对照相比,4份材料的简易活力指数、胚根数、胚根长、株高分别低于对照21.9%~76.5%、20.0%~40.9%、14.6%~55.9%、23.9%~36.2%,均呈现显著差异。盐胁迫条件下外源添加IAA使盐敏材料简易活力指数提高2.6%和13.3%。而添加CaCl₂能使简易活力指数提高9.6%~24.8%,胚根长和株高提高7.1%~49.0%和14.7%~20.9%。经CaCl₂+IAA复合处理,简易活力指数、胚根数和株高分别提高6.9%~94.6%、2.1%~21.2%和9.9%~20.3%。水稻萌发和幼苗生长对外源物质的响应与基因型和形态指标相关。盐胁迫条件下,3项指标对外源CaCl₂处理的响应程度高于IAA处理。且CaCl₂+IAA复合处理能更有效抵消盐害对水稻生长的抑制作用。     

Responses of Some Newly Developed Salt-tolerant Genotypes of Spring Wheat to Salt Stress: 1. Yield Components and Ion Distribution

The degree of salt tolerance of two newly developed genotypes of spring wheat, S24 and S36 was assessed with respect to their parents, LU26S (from Pakistan) and Kharchia (from India). These four lines along with a salt-tolerant genotype SARC-1 and two salt-sensitive cvs Potohar and Yecora Rojo were subjected to salinized sand culture containing 0, 125 or 250 mol m^?3 NaCl in full strength Hoagland's nutrient solution. S24 produced significantly greater grain yield and had greater 1000 seed weight and number of tillers per plant than those of the other cultivars /lines. S36 was not significantly different from its parents in seed yield and yield components. SARC-1 was the second highest in grain yield of all cultivars/lines, but it did not differ significantly from LU26S and Kharchia in 1000 seed weight and number of tillers per plant. The greater degree of salt tolerance of S24 could be related to its lower accumulation of Na⁺ in the leaves and maintenance of higher leaf K/Na ratios and K versus Na selectivity as compared to its parents. S36, which was as good as its parents in growth, also had lower Na⁺ and higher K/Na ratios and K versus Na selectivity in the leaves at the highest salt level than those in its parents. SARC-1 did not differ from LU26S and Kharchia in ionic content or K/Na ratios and K versus Na selectivities of both leaves and roots. Both the salt-sensitive cultivars, Potohar and Yecora Rojo, had significantly greater leaf Na⁺ and Cl^? concentrations and lower leaf K/Na ratios and K versus Na selectivities than all the salt-tolerant lines examined in this study. From this study it is evident that improvement in salt tolerance of spring wheat is possible through selection and breeding, and pattern of ion accumulation is not consistent among the salt-tolerant genotypes in relation to their degree of salt tolerance.