盐碱胁迫对辣椒种子萌发的影响

研究了不同浓度的Na2CO3,和NaHCO3,对辣椒种子萌发的胁迫作用.结果表明,两种盐碱胁迫均可降低辣椒种子的发芽率,对发芽势的影响则均表现为随着浓度升高呈先升高后降低的趋势,对发芽起始时间没有影响.盐碱胁迫提高了辣椒芽苗膜的透性和丙二醛含量,芽苗体内的POD、SOD、CAT三种保护性酶活性均随着浓度升高呈先上升后降低的趋势.相同浓度下,Na2CO3,比NaHCO3,对辣椒种子萌发的抑制作用更强.     

盐碱胁迫下棉花幼苗对外源褪黑素的生理响应

新疆土壤盐碱化严重影响棉花种子的萌发及幼苗生长,本试验通过分析外源褪黑素对盐碱胁迫下棉花幼苗生长指标的影响,了解褪黑素对盐碱胁迫下棉花幼苗的调控效应;通过盆栽试验,分析了盐碱胁迫下喷施外源褪黑素对棉花幼苗生长、抗氧化酶活性及有机酸含量的影响。结果发现,在盐碱胁迫下,棉花幼苗的生长受到了抑制,过氧化氢与丙二醛含量显著增加,过氧化氢酶、超氧化物酶活性降低,有机酸含量提高。在盐碱胁迫下,施用外源褪黑素可缓解棉花幼苗的盐碱毒害症状,增加植株生物量。SOD、CAT的活性显著提高,H2O2与MDA的积累减少,从而减轻了盐碱胁迫对棉花的损害,提高了棉花苗期对盐碱胁迫的耐受性。     

褪黑素对低温胁迫下棉花种子萌发特性的影响

低温胁迫严重影响棉花种子萌发,为明确褪黑素对低温胁迫下棉花种子萌发的调控作用,本研究以海岛棉品种‘新海41号’为试验材料,分析不同褪黑素浓度处理对低温胁迫(15℃)下棉花种子的萌发特性、抗氧化酶活性、丙二醛(MDA)和过氧化氢含量影响。结果表明,低温下棉花种子发芽率、发芽势和发芽指数较常温对照分别降低17.41%、13.52%和74.96%,胚根长度降低40.35%,SOD、POD、CAT活性略有增高,MDA和H₂O₂含量有所增加。低浓度的褪黑素（10 μmol/L和20 μmol/L）处理显著增加了低温胁迫下棉花种子发芽势、发芽率、发芽指数以及胚根长度,增强抗氧化酶的活性,减少MDA、H₂O₂的产生,其中20 μmol/L褪黑素处理后,与低温对照相比SOD、POD、CAT活性分别上升3.53%、29.47%、3.45%,MDA和H₂O₂含量分别减少13.93%和8.08%。适宜浓度的褪黑素处理能有效缓解低温胁迫对棉花种子萌发的损伤,增强种子耐低温性,其中20 μmol/L褪黑素处理效果最好。     

褪黑素对盐胁迫下高粱种子萌发的缓解效应及生理机制

为了探究外源褪黑素影响高粱种子耐盐性的机理，本研究以粒用高粱品种晋杂2002的种子为试验材料，分析盐胁迫下褪黑素浸种对高粱种子萌发及生理特性的影响。结果表明，盐胁迫能明显抑制高粱种子萌发，增加相对电导率及丙二醛含量，使其干物质积累量减少；适宜浓度褪黑素浸种能缓解盐胁迫对高粱种子萌发的抑制作用。褪黑素浸种可通过提高高粱种子萌发过程中抗氧化酶活性，清除过量活性氧积累，减轻膜脂过氧化程度；增加渗透调节物质含量，维持细胞膨压，提高吸水能力；同时还可增加种子胚根根系活力，提高胚芽绿色部分光合色素含量，这些变化共同提高了高粱种子萌发期抵御盐胁迫的能力，促进其种子萌发及干物质积累；通过主成分分析法筛选出胚芽长度和可溶性糖含量两个指标可作为褪黑素缓解盐胁迫下高粱种子萌发的评价指标。     

烯效唑浸种对盐碱胁迫下藜麦农艺性状及生理特性的影响

为了探究烯效唑浸种处理对盐碱胁迫下藜麦幼苗生长的缓解效应,以陇藜1号为试验材料,采用盆栽法研究不同浓度烯效唑（0、15、30、45和60 mg/L）浸种处理对不同程度盐碱胁迫（CK 0 g/kg、轻度盐碱3 g/kg、中度盐碱5 g/kg、重度盐碱7 g/kg）下藜麦苗期（播种后28 d）农艺性状及生理参数的影响。结果表明,藜麦幼苗渗透物质含量、抗氧化酶活性及根系活力在轻度盐碱胁迫（3 g/kg）下均有所提高,以应对盐碱环境,缓解氧化损伤;根冠比和壮苗指数在中度盐碱（5 g/kg）处理下达到最大;藜麦幼苗农艺参数、光合参数、渗透物质含量、抗氧化酶活性及根系活力在重度盐碱胁迫下明显下降,丙二醛含量在重度盐碱胁迫（7 g/kg）下达到最大,说明盐碱程度的加深显著影响藜麦幼苗的生长。在同一盐碱水平上,低浓度烯效唑浸种处理后,藜麦幼苗的根冠比、壮苗指数、叶绿素含量、渗透物质含量、抗氧化酶活性和根系活力均显著升高,丙二醛含量有所下降,且浸种浓度在15 mg/L时缓解盐胁迫效应最为显著。     

外源腐胺对盐胁迫下菜豆种子萌发及抗性的影响

为了探究外源腐胺对盐胁迫下菜豆种子萌发的影响，本研究以菜豆品种‘P16028’为试验材料，设置蒸馏水对照(CK)、100 mmol/L NaCl处理(NaCl)以及NaCl处理条件下添加1 mmol/L Put浸种(NaCl+1 Put) 3个处理组，对其发芽势、发芽率、发芽指数及生理指标进行测定。结果表明：与CK相比，盐胁迫导致菜豆种子发芽势、发芽率、发芽指数显著降低，抗氧化酶SOD、POD、CAT均呈下降趋势，其O₂^-、MDA、可溶性蛋白、可溶性糖含量和脯氨酸含量上升，种子萌发受到抑制。而添加外源Put显著提高了盐胁迫下菜豆种子发芽势、发芽率、发芽指数，也提高了SOD、POD、CAT氧化酶活性，降低其O₂^-和MDA含量，提升渗透调节物质含量，提高菜豆对盐胁迫的抗性。由此可见，使用外源Put浸种可以缓解盐胁迫带来的伤害，提高菜豆种子的耐盐性，从而有效的促进菜豆种子的萌发。     

褪黑素与2,4-表油菜素内酯浸种对盐胁迫下荞麦发芽与幼苗生长的促进效应

土壤盐渍化是影响农作物种子萌发出苗以及生长发育的重要限制因素,探究外源激素对盐胁迫条件下荞麦种子萌发与幼苗生长的缓解作用具有重要意义。本试验以荞麦品种西农9976为材料,采用培养皿萌发和盆栽发芽2种方法,研究褪黑素(MT)与2,4-表油菜素内酯(EBR)浸种对不同盐浓度胁迫下荞麦种子萌发、幼苗生长、抗氧化酶活性、渗透调节物质的影响。结果表明,盐胁迫增加了荞麦种子和幼苗叶片丙二醛(MDA)含量、可溶性糖含量和抗氧化酶(SOD、POD、CAT)活性,降低了荞麦种子发芽势、发芽率和成苗率,使荞麦种子胚芽长度、胚根长度和幼苗高度显著下降。MT、EBR浸种荞麦种子可有效缓解盐胁迫危害,使荞麦种子发芽势、发芽率和成苗率较对照分别增加14.9%～33.3%、11.5%～27.3%和20.0%～46.2%,显著提高荞麦种子胚根长度、胚芽长度、胚芽鲜重和干重、幼苗高度、幼苗鲜重和干重,并显著增加荞麦种子和幼苗叶片中可溶性糖含量和SOD、POD、CAT活性,降低MDA含量。综上所述, MT和EBR浸种均能通过提高荞麦种子保护酶活性、减少活性氧积累、增加渗透调节物质含量,促进盐胁迫条件下荞麦种子发芽及幼苗生...     

壳聚糖浸种对干旱胁迫下苜蓿种子发芽的缓解作用

以苜蓿种子为试材,采用不同浓度壳聚糖溶液对苜蓿进行浸种处理,测定其对干旱胁迫下苜蓿种子发芽和幼苗生长的影响,旨在寻找苜蓿发芽阶段抗干旱胁迫的最佳浸种浓度。结果表明:随着壳聚糖溶液处理浓度的升高,干旱胁迫下苜蓿种子发芽率、发芽势、发芽指数、活力指数、苗高与根长均呈现先上升后下降的趋势。隶属函数综合分析表明,壳聚糖溶液浸种对干旱胁迫下苜蓿种子发芽能力的影响效果由大到小依次为:100 mg/L、50 mg/L、25 mg/L、150 mg/L、0 mg/L、200 mg/L,以100 mg/L的壳聚糖浸种处理对提高苜蓿种子发芽阶段抗干旱胁迫的效果最佳。     

淹水胁迫下褪黑素浸种对水稻幼苗生长的影响

为研究淹水胁迫下褪黑素浸种对长短中胚轴水稻幼苗期生理和生化性状的影响,采用不同浓度梯度的褪黑素(MT)处理,测定中胚轴长、胚芽鞘长、芽长、鲜质量、成活率等相关农艺性状,测定过氧化物歧化酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)的活性以及丙二醛(MDA)含量等生理生化指标。MT浸种对淹水胁迫下水稻生长的影响可分为低浓度缓解胁迫和高浓度加剧毒害;淹水处理下相比短中胚轴品种华航31、DH4040,长中胚轴品种鄂中4号、DH4038具有较高的成活率;在对4个品种添加10,100μmol/L的MT浸种处理时,华航31中MT浸种效果表现均是最好的,其中100μmol/L MT浸种处理在每个品种中均能显著提高幼苗的成活率。随着浓度提高到1 000μmol/L,对所有的品种均表现为抑制成活;MT浸种可降低MDA含量,提高POD、SOD、CAT活性,促进中胚轴长、胚芽鞘长、芽长、鲜质量等农艺性状,100μmol/L MT浸种处理效果最好;1 000μmol/L MT浸种也可以促进相关农艺性状提升并提高酶活性,但成活率显著下降。适当浓度的褪黑素浸种,能提高淹水胁迫下水稻幼苗活力和出苗率,显著降低淹水胁迫对水稻幼苗的毒害作用。     

3种草本植物种子萌发及幼苗初期对镉胁迫的生理响应

通过溶液培养探讨了不同浓度镉胁迫下,韭菜、凤仙花和紫云英种子萌发及幼苗初期叶绿素、丙二醛含量及抗氧化酶活性的变化.结果表明:低镉浓度(≤50 mg/L)促进种子萌发,中高浓度(≥100 mg/L)抑制种子萌发;发芽指数和活力指数均随着镉浓度增加而下降;当镉≥50 mg/L时,根长和芽长均与对照差异显著(p＜0.05),明显阻碍幼苗生长,且根比芽对胁迫敏感;高浓度镉明显阻碍叶绿素的合成;丙二醛含量及抗氧化酶活性均随着胁迫浓度提高呈先升后降的趋势,说明低浓度镉激活植物自身的保护系统发挥作用,高浓度镉抑制其发挥作用.     

外源褪黑素对低温胁迫下菜豆种子萌发及抗性的影响

为了探究褪黑素(Mt)对低温环境下菜豆种子的影响,本研究对菜豆种子进行低温处理(LT)和低温加褪黑素的处理(LT+Mt),并设置常温处理作为对照(CK),对同时期的各项生理指标进行测定。结果表明：Mt可以提高低温胁迫下的种子萌发率,但萌发率要低于对照;同时对渗透调节物质、O₂^-和MDA、抗氧化酶活性进行测定,发现低温增加了渗透调节物质的含量,当加入Mt后其含量进一步增加;低温处理后O₂^-和MDA的含量增加,当加入Mt后其含量明显降低,但是要高于对照;低温处理后抗氧化酶活性略低于对照,当加入Mt后其含量显著升高。研究表明外源Mt有效的减轻了低温对种子萌发的损害,从而促进种子萌发过程中抵御低温的能力。     

Correlations between the stability and adaptability statistics of popcorn cultivars

In plant breeding, correlations between the statistics of stability and adaptability of popcorn cultivars are not yet well understood. Therefore, the objectives of the present experiment was to investigate the correlations between s_di² \sigma_{\rm di}^{2} and b_i \beta_{\rm i} from Eberhart and Russell, ω_i from Wricke, \textS_\texti⁽¹⁾ {\text{S}}_{\text{i}}^{(1)} , \textS_\texti⁽²⁾ {\text{S}}_{\text{i}}^{(2)} and \textS_\texti⁽³⁾ {\text{S}}_{\text{i}}^{(3)} from Huehn, P_i from Lin and Binns and the rank-sum from Kang, and indicate the most reliable method for selecting popcorn cultivars. These statistics were estimated by data of crop yield from 19 Brazilian genotypes under 21 environments and popping expansion under 16 environments. The ω_i, \textS_\texti⁽¹⁾ {\text{S}}_{\text{i}}^{(1)} , \textS_\texti⁽²⁾ {\text{S}}_{\text{i}}^{(2)} , \textS_\texti⁽³⁾ {\text{S}}_{\text{i}}^{(3)} and s_di² \sigma_{\rm di}^{2} were positively and significantly correlated indicating that just one in these five statistics is sufficient for selecting stable genotypes although they were not correlated with the means of crop yield and popping expansion. The b_i \beta_{\rm i} was negatively and significantly correlated with P_i for crop yield indicating that the most adaptable genotypes tend to have the lowest estimates of P_i. Although P_i was not correlated with ω_i, \textS_\texti⁽¹⁾ {\text{S}}_{\text{i}}^{(1)} , \textS_\texti⁽²⁾ {\text{S}}_{\text{i}}^{(2)} , \textS_\texti⁽³⁾ {\text{S}}_{\text{i}}^{(3)} , or s_di² \sigma_{\rm di}^{2} statistics, it displayed positive correlation with the Index 1 (crop yield and popping expansion +  \textS_\texti⁽¹⁾ {\text{S}}_{\text{i}}^{(1)} rank) and Index 2 (crop yield and popping expansion + W_i) indicating that superior popcorn genotypes are also stable. Finally, both P_i and the rank-sum are useful statistics in breeding programmes where crop yield, popping expansion and stability are essential traits for selecting genotypes.     

玉米种子萌发期抗旱性鉴定方法及不同杂交种抗旱性比较研究

用PEG-6000高渗溶液模拟土壤水分胁迫的方法,比较了培养介质、浸种时间对不同粒质量类型玉米种子发芽率的影响,并采用砂培不浸种方式,研究了黄淮海地区近几年审定的32个玉米杂交种萌发期的抗旱性。结果表明:不同类型的玉米品种,在纸培模式下20%PEG渗透胁迫处理的发芽率均低于或等于25%,远低于砂培模式。砂培模式下,不浸种处理的发芽率总体好于浸种24 h和48 h处理。砂培不浸种方式下,渗透胁迫处理不同程度地降低了32个玉米杂交种种子的发芽率;大多数品种初生根条数低于对照,胚芽长和胚根长均减小,胚芽长比胚根长减小的程度大,胚芽干质量显著降低。     

Genetic and phenotypic parameters in common bean segregant populations from intra and inter-gene pool crosses of elite lines

This study aimed compare segregating populations of common bean (Phaseolus vulgaris L.) derived from intra and inter-gene pool crosses of elite lines by estimates of some genetic and phenotypic parameters. Four elite lines highly adapted to Brazilian conditions were used (ESAL 686 and BRS Radiante: Andean gene pool; BRSMG Majestoso and BRS Valente: Mesoamerican gene pool). Two intra-gene pool (“A”: ESAL 686 × BRS Radiante; “B”: BRS Valente × BRSMG Majestoso) and two inter-gene pool segregant populations (“C”: BRS Radiante × BRSMG Majestoso and “D”: ESAL 686 × BRS Valente) were obtained. The parental lines, the cultivar Pérola and fifty-five F_2:3 progenies of each population were evaluated in the rainy season 2010/2011, and afterwards (F_2:4) in dry season of 2011. Estimates of genetic variance ( $\hat{\sigma }_{G}^{2}$ ), heritability on a progeny mean basis ( $\hat{h}_{p}^{2}$ ), heritability realized ( $\hat{h}_{R}^{2}$ ) and gain expected from selection (GS) were obtained at joint analysis, in each population, for the traits number of days to flowering (DTF), 100 seed weight (100SW) and seed yield (SYD). It was observed that for all traits, inter-gene pool crosses (“C” and “D”) showed higher estimates of $\hat{\sigma }_{G}^{2}$ , $\hat{h}_{p}^{2}$ , $\hat{h}_{R}^{2}$ and GS than intra-gene pool crosses (“A” and “B”), which indicates more genetic variability. However, for SYD, the higher variability was associated to lower average of seed yield, showing that even utilizing adapted parents the inter-gene pool crosses are inferior to crosses between lines of the same gene pool.     

盐胁迫对膜荚黄芪种子萌发的影响

为了保护并开发膜荚黄芪,同时改良盐碱地,研究了3种不同盐（中性盐NaCl、碱性盐Na₂CO₃和复盐）对膜荚黄芪种子发芽率、发芽势、抗氧化酶活性、丙二醛含量、可溶性蛋白质含量和相对电导率的影响。结果表明,不同盐胁迫对膜荚黄芪种子的影响不同,随着盐浓度的增加,黄芪种子的发芽率和发芽势逐渐降低;低浓度的NaCl和复盐可提高抗氧化酶活性,Na₂CO₃处理随着其浓度增加对抗氧化酶活性的抑制作用增强;各处理均增大了丙二醛含量和相对电导率;NaCl和复盐处理降低了膜荚黄芪种子可溶性蛋白含量,Na₂CO₃处理的可溶性蛋白含量随盐浓度增加而增加,综合各项指标可得同等盐浓度条件下胁迫作用由强到弱为Na₂CO₃>NaCl>复盐。     

盐分胁迫下2-氯-6-(三氯甲基)吡啶浸种对棉种发芽及其生理特性的影响

通过设置0、80、120 mmol·L-1 3种NaCl浓度,研究了3种盐分水平下2-氯-6-(三氯甲基)吡啶浸种对棉种发芽的影响,分析了棉种萌发过程中可溶性蛋白、可溶性糖、抗氧化物酶及丙二醛含量对2-氯-6-(三氯甲基)吡啶浸种的生理响应.结果表明,盐分胁迫显著抑制了棉种的萌发,而2-氯-6-(三氯甲基)吡啶浸种能明显减轻盐分胁迫对种子发芽的抑制.在3个盐分水平(0、80、120 mmol·L-1)下,2-氯-6-(三氯甲基)吡啶浸种处理的发芽率、发芽势及种子活力指数均比清水浸种有显著提高,其增幅分别为11.5％～58.4％、16.8％～65.0％和42.9％～82.5％;同时,2-氯-6-(三氯甲基)吡啶浸种可显著提高棉种SOD、POD、CAT的活性,分别比清水浸种增加了57.2％～282.7％、8.3％～139.3％和6.4％～15.1％,且显著降低了电解质外渗率与MDA含量.在盐分胁迫下,利用4.1×10-3 mmol· L-1的2-氯-6-(三氯甲基)吡啶浸种可提高棉种抗氧化物酶活性,促进其萌发过程中可溶性有机物的转化,显著提高棉种发芽率和发芽势.     

Effects of Melatonin on the Antioxidant Enzyme Activities and Seed Germination of Cotton (Gossypium hirsutum L.) under Salt-Stress Conditions

[Objective] Cotton (Gossypium hirsutum L.) seed germination, in which melatonin plays an important regulatory role, is seriously affected by soil salinization. Cotton seed germination, antioxidant enzyme activity levels and other physiological indicators were analyzed to clarify the regulatory effects of exogenous melatonin on cotton seed germination under salt-stress conditions. [Method] The experiment was conducted in a greenhouse of Hebei Agricultural University in Baoding City, Hebei Province from 2018 to 2019 using Guoxin Cotton 9 as the material. The germination rate, germination potential, seed biomass after germination, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities, as well as the malondialdehyde (MDA) content, of cotton seeds were measured after exposure to different melatonin concentrations (0, 10, 20, 50 and 100 μmol·L^－1) and 150 mmol·L^－1 NaCl treatments. [Result] After germination, the germination rate, germination potential, radical length and seed biomass significantly decreased, as did the SOD, POD and CAT activities. However, the MDA content significantly increased under salt-stress conditions. Low exogenous melatonin concentrations (10 and 20 μmol·L^－1) increased the germination potential, germination rate and biomass of cotton seeds, and promoted the elongation of radicals; however high melatonin concentrations (50 and 100 μmol·L^－1) inhibited cotton seed germination and decreased seed biomass after germination. Low melatonin concentrations (10 and 20 μmol·L^－1) increased the SOD, POD and CAT activities and decreased the MDA content in cotton seeds. [Conclusion] Low melatonin concentrations could promote germination and improve the salt tolerance of cotton seeds, while high melatonin concentrations could inhibit their germination. A 20 μmol·L^－1 melatonin concentration is appropriate for regulating cotton seed germination under salt-stress conditions.     

贮藏时间对烟草品种红花大金元种子萌发和生理特性的影响

探讨烟草种子萌发和生理生化特性在不同贮藏时间的变化情况,为烟草种质资源保存和田间生产提供参考。以常温贮藏0~12个月的烟草品种“红花大金元”种子为试验材料,研究其萌发特性、抗氧化酶活性、渗透调节物质（脯氨酸、可溶性糖）、丙二醛（MDA）含量和相对电导率在贮藏过程中的变化。结果表明,种子的活力指数、发芽势、发芽率和发芽指数均随着贮藏时间的延长呈先升高后降低的趋势,贮藏6个月的种子发芽率最高,达到93.21%,贮藏12个月的种子基本失去萌发活性;随着贮藏时间的延长,超氧化物歧化酶、过氧化物酶和过氧化氢酶活性以及脯氨酸和可溶性糖含量整体上呈不断下降的趋势,MDA含量和相对电导率整体上呈不断提高的趋势。可见,烟草种子老化过程中,萌发能力先升高后降低,抗氧化酶活性整体下降,渗透调节物质消耗减少,细胞膜损伤加剧,在实际生产中,建议选择常温贮藏6个月内的种子。