混合盐碱胁迫对水稻种子萌发的影响

为探明混合盐碱胁迫对水稻(Oryza sativa L.)种子萌发的影响,采用纸上萌发法,用不同浓度的NaCl、Na2 SO、NaHCO3和Na2 CO3混合液对水稻种子进行萌发试验.结果表明:在混合盐碱胁迫下,水稻种子的发芽率、发芽势、发芽指数和活力指数均随盐浓度的升高和pH值增大呈下降趋势.低盐或低碱胁迫对水稻种子萌发影响较小,高盐或高碱胁迫下水稻种子萌发受到严重影响,水稻种子萌发主要受到盐浓度的影响,当盐浓度达200 mmol/L时,各盐组合水稻种子均不萌发.     

盐碱胁迫对小麦幼苗根系活力和苯丙氨酸解氨酶活性的影响

分别采用两种中性盐(NaCl和Na2SO4)和两种碱性盐(NaHCO3和Na2CO3)混合模拟不同浓度的盐碱胁迫条件,对龙麦26和克旱16两种不同基因型春小麦幼苗进行7d胁迫处理。分别测定叶片中苯丙氨酸解氨酶活性和根系活力,以探讨盐、碱两种胁迫下小麦根系对离子交换吸附能力的影响。结果表明:盐碱混合胁迫增强了小麦叶片的苯丙氨酸解氨酶活性,增加了根系活跃吸收面积,增大了根系活力。这3个指标受胁迫溶液离子浓度、pH值、碱性盐比例等多重影响,且品种间存在一定差异性。     

盐碱胁迫对小冰麦种子萌发和早期幼苗生长的影响

分别将两种中性盐(NaCl和Na2SO4)与两种碱性盐(NaHCO3和Na2CO3)均按摩尔比9∶1混合,在模拟出不同强度的盐碱胁迫条件。比较了盐碱胁迫对小冰麦种子萌发、早期幼苗生长及幼苗中Na+、K+离子含量的影响。结果表明,碱胁迫对小冰麦种子萌发的抑制作用明显大于盐胁迫,而碱胁迫对萌发的抑制可能是致死的。碱胁迫对早期幼苗生长的抑制作用也明显大于盐胁迫,尤其对幼根的抑制作用。碱胁迫明显破坏根的结构和功能,导致根活力急剧下降。盐碱胁迫均造成芽和幼根Na+含量上升而K+含量下降,Na+/K+也随之升高。但若两种胁迫相比,碱胁迫下Na+含量及Na+/K+比值上升幅度和K+含量下降幅度均大于盐胁迫。小冰麦的Na+、K+含量变化特点表明,碱胁迫造成的高pH干扰了根系选择性吸收K+、Na+的能力,而造成了植物体内Na+、K+不均衡,这可能是碱胁迫对小冰麦的伤害作用大于盐胁迫的原因所在。     

氯化钠和碳酸钠对芦笋的胁迫效应比较

对一年生芦笋幼苗用0、0.1、0.2、0.3mol/L的中性盐NaCl和碱性盐Na2CO3处理,检测芦笋对盐碱的耐受程度。结果表明:在两种盐胁迫下MDA含量、叶绿素含量及质膜透性的变化趋势基本相似,但碱性盐Na2CO3胁迫使MDA含量急剧上升,质膜透性也明显增加,叶绿素含量下降显著,表明碱性盐Na2CO3对芦笋破坏较中性盐NaCl严重。两种盐对渗透调节物质含量的影响上表现为碱性盐Na2CO3处理使脯氨酸、可溶性蛋白含量增加显著,中性盐NaCl处理使可溶性糖含量增加明显,说明芦笋可通过增加渗透调节物质含量提高对盐碱的抵抗能力。     

NaCl和Na2CO3胁迫对内蒙古河套灌区盐地碱蓬种子萌芽生理指标的影响

采用NaCl和Na2CO3胁迫不同时间,研究盐地碱蓬种子在萌发过程中对NaCl和Na2CO3的耐受能力,对比不同胁迫对盐地碱蓬正在萌芽种子的SOD、POD、MDA、可溶性糖、可溶性蛋白和游离脯氨酸等胁迫相关生理指标的影响.结果显示,盐碱胁迫下可溶性蛋白变化较为平缓,SOD活性呈现“先降后升再降”的变化趋势,POD、MDA、可溶性糖和游离脯氨酸含量呈现上升趋势.研究发现,盐地碱蓬萌发种子萌发对NaCl的耐受能力强于Na2CO3.     

盐碱胁迫对野生地肤种子发芽和幼苗生长的影响

将中性盐NaCl、Na2SO4和NaHCO3、Na2CO3两种碱性盐按不同比例混合,模拟出30种与天然盐碱土壤相似的条件,进行野生地肤种子发芽试验和幼苗生长情况检测等7项指标,结果表明:在混合盐碱胁迫作用下,地肤种子发芽受到明显抑制,发芽率、发芽势、发芽指数等指标呈下降趋势,并随盐碱度递增,下降程度逐渐增大,高盐高碱效应较单独高盐或高碱作用大;幼苗存活率和相对含水量在不同处理组间均呈下降趋势,而MDA和可溶性糖含量则随着盐碱度的升高逐渐上升,其中可溶性糖含量在低盐浓度(50、100 mmol/L)或低pH条件下,增加幅度小于高盐浓度(200、250 mmol/L)或高pH,两者具有明显的协同作用。     

温度与盐、碱胁迫交互作用对小麦种子萌发的影响

采用3种变温处理(10~20℃,15~25℃与25~35℃),并分别混合两种中性盐(NaCl∶Na2SO4=4∶1)与碱性盐(NaHCO3∶Na2CO3=4∶1)模拟盐、碱胁迫条件,探讨盐碱胁迫与温度交互作用对小麦种子萌发的影响。结果表明,随着盐碱胁迫浓度的增大,种子发芽率与发芽速率均不断下降,且在碱胁迫下下降幅度更大。盐胁迫下,15~25℃与25~35℃对种子发芽率影响无显著差异,并且在25~35℃下发芽速率更高,而碱胁迫下,15~25℃更有利于小麦种子的萌发。另外,无论是在盐胁迫还是碱胁迫下,10~20℃低温均对种子抑制效应最强。上述结果表明,盐、碱胁迫及与温度交互作用对小麦种子萌发的影响明显不同,由于碱胁迫具有高pH值对种子的伤害更大,小麦种子萌发期耐盐碱性在低温下会大幅下降。     

亚精胺对混合盐碱胁迫下桔梗种子萌发特性的影响

为明确桔梗种子萌发在混合盐碱胁迫下所受的影响,并寻求提高桔梗种子在盐碱胁迫条件下萌发力的方法,以桔梗种子为研究材料,将两种中性盐(NaCl, Na₂SO₄)和两种碱性盐(NaHCO₃,Na₂CO₃)按不同的比例混合,交叉模拟出20种不同的混合盐碱组合,研究混合盐碱胁迫对桔梗种子萌发的影响,并深入研究不同浓度亚精胺在筛选出的抑制最显著的混合盐碱浓度组合C(1∶9∶9∶1)胁迫下对桔梗种子各项发芽指标的影响。结果表明,混合盐碱胁迫对桔梗种子的发芽率、发芽势、发芽指数、活力指数及相对盐害率均有不同程度的影响,且通过相关性分析表明,盐碱浓度是抑制桔梗种子发芽的主导因素。施用外源性物质亚精胺后,低浓度亚精胺可促进桔梗种子在盐碱胁迫下的萌发,高浓度反而抑制,本研究中最适桔梗种子萌发的亚精胺浓度为0.5 mmol/L。本研究可为桔梗规范化种植过程中的盐碱地选择及提高桔梗种子耐盐性提供理论依据。     

盐碱胁迫对芸豆根际土壤微生物数量及酶活性的影响

为了探究芸豆根际微生态环境对盐胁迫的响应机制,以HYD和JW为试验材料,采用盆栽法,将2种碱性盐Na2CO3、Na HCO3按摩尔比1∶9混合,按混合后占土壤质量分数0(S0),0. 4%(S1),0. 8%(S2),1. 2%(S3)设计4个浓度梯度,研究不同程度盐碱胁迫对芸豆根际土壤微生物数量和土壤酶活性的影响。结果表明,在盐碱胁迫下,HYD在株高、根长和地上、下生物量等优于JW。在盐碱胁迫处理下根际土壤细菌、真菌和放线菌数量差异显著,细菌数量高于真菌和放线菌数量。两芸豆品种根际土壤脲酶、磷酸酶、过氧化氢酶活性与土壤微生物数量均在S1处理下达到最大值,且差异显著。在相同处理下,HYD的株高、根长和地上、地下生物量等生长特性与根际土壤微生物数量、酶活性均显著高于JW。相关分析表明,脲酶活性与细菌数量、真菌数量、放线菌数量和微生物总量呈显著或极显著正相关,磷酸酶活性与放线菌数量、过氧化氢酶活性与真菌数量均呈显著正相关。在盐碱胁迫条件下,p H值上升,微生物数量发生变化,导致酶活性改变,间接改变根际土壤微环境。一定量的盐碱胁迫有利于提高芸豆根际土壤微生物数量及酶活性,促进芸豆生长。     

人工模拟盐、碱环境对向日葵种子萌发及幼苗生长的影响

以向日葵品种白葵杂6号为试验材料, 中性盐NaCl和Na₂SO₄混合模拟盐胁迫、碱性盐NaHCO₃和Na₂CO₃混合模拟碱胁迫(两者摩尔比均为9∶1), 设计各6种处理。研究盐、碱胁迫下种子萌发及幼苗形成的相关生理表现。结果表明, 种子能够萌发并成苗的最高盐胁迫强度是pH 6.98, 电导率为1.311 dS m^-1(培养介质的pH和电导率); 碱胁迫强度是pH 9.71, 电导率为0.360 dS m^-1。在能够成苗的盐碱条件下, 随着盐胁迫强度的增强出苗率、成苗率下降, 出苗时间明显延迟; 而随着碱胁迫强度的增加, 成苗率下降, 出苗时间并不延迟。同时随着盐碱胁迫强度的增强, 幼苗的各项生理指标均下降, 下降幅度以碱胁迫明显大于盐胁迫。试验结果证明, 盐胁迫和碱胁迫对白葵杂6号种子萌发及幼苗形成的影响机制不同, 向日葵在这两个阶段对盐碱两种胁迫的耐受能力及响应特点也不同。这一结论进一步证实了盐、碱胁迫是两种性质不同的胁迫。     

混合盐胁迫对茶花凤仙种子萌发的影响

以茶花凤仙种子为试材,将NaCl、Na_2SO_4、NaHCO_3和Na_2CO_3按1∶1∶1∶1和0∶0∶1∶1两种摩尔配比人工模拟pH值分别为9.56和10.68的盐碱混合胁迫条件,探讨混合盐胁迫对其种子萌发指标的影响,明确种子萌发期对混合盐胁迫的耐受性。结果表明:2种混合盐胁迫处理下,茶花凤仙种子初始萌发时间滞后;与对照相比,种子发芽率呈现"低促高抑"现象,而发芽势、发芽指数和活力指数均随混合盐浓度的升高而逐渐降低。解除混合盐胁迫后,pH值为9.56处理下的茶花凤仙种子仍具有一定的萌发力,而pH值为10.68处理下的种子已完全失活。茶花凤仙种子萌发阶段对2种混合盐胁迫的耐盐适宜浓度分别为68.05 mmol·L^-1,60.53 mmol·L^-1,耐盐半致死浓度分别为119.59 mmol·L^-1,101.18 mmol·L^-1,耐盐极限浓度分别为202.07 mmol·L^-1,166.22 mmol·L^-1。     

混合盐碱胁迫对橡胶草种子萌发的影响

以野生橡胶草为研究材料,将中性盐(NaCl、Na_2SO_4)和碱性盐(NaHCO_3、Na_2CO_3)按不同比例和浓度配制成25组梯度混合盐溶液,采用室内培养法观察了混合盐胁迫对橡胶草种子萌发的影响。结果表明:随着盐浓度的增加,相对盐害率上升,发芽率、发芽势、发芽指数、活力指数和初生根长度均呈下降趋势;在相同盐浓度条件下,pH值高的混合盐对种子萌发的抑制作用更强;逐步回归分析表明,盐浓度是抑制种子萌发的主导因素,pH值的影响次之。     

Ionic Homeostasis and Expression of Na+ Related Genes of Cotton under Different Salt and Alkali Stresses

[Objective] Maintaining intracellular ion homeostasis is one of the important salt-tolerant mechanisms of crops. This study aims to analyze differences in response characteristics of cotton ionome and salt-tolerant gene expression under different saline-alkali stresses, which provides a basis for understanding the mechanism of salt tolerance and improving salt tolerance of cotton. [Method] Using Lumianyan 24 as the experimental material, three kinds of salt and alkali stress types (salt stress, alkali stress, and mixed salt-alkali stress) and two concentration gradients (low and high concentrations) were set under pot cultivation conditions. Meanwhile, non-saline-alkali stress treatment was set as control. The dry matter weight of cotton plants and root morphological parameters including root length, root surface area, and root volume were measured in this study. The concentrations of 13 elements such as P, Na, K, Ca and Mg in different organs of cotton plants were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The relative expressions of salt tolerance related genes GhDFR1, GhSOS1, GhNHX1 and GhAKT1 were determined by the quantitative real-time polymerase chain reaction method. [Result] 1) Salt and alkali stresses significantly inhibited cotton growth. The growth inhibition rate of cotton under mixed salt-alkali stress treatments (48.7%–57.9%) was significantly higher than that under salt stress (27.6%–49.9%) and alkali stress (21.2%–35.5%) treatments. Under salt stress and mixed salt-alkali stress treatments, both shoot and root growth of cotton were significantly inhibited, dry matter weight, root length, root surface area and root volume were significantly reduced, while root growth was less inhibited under alkali stress treatments. 2) Under three types of saline-alkali stresses, Na content and Mo content in different organs of cotton plant increased significantly, but N content in leaves and roots decreased. 3) Under salt stress treatments, the uptake of Ca, Mg, Fe, Mn and Zn in cotton was inhibited, and the ion balance was maintained by promoting the transport of these ions and P, K. 4) In addition to Ca, Mg, Fe, Mn and Zn, P uptake was also inhibited under alkali stress treatments, but K uptake and P, K, Ca, Mg, Fe, Mn and Zn transport were promoted. 5) Under mixed salt-alkali stress treatments, especially under high salinity and pH conditions, most of nutrients uptake was inhibited, and the transport capacity of Ca, Mg, Zn, Mn and Fe was reduced. 6) The relative expression of GhSOS1 and GhAKT1 genes increased significantly under salt stress treatments, but increased first and then decreased under alkali stress and mixed salt-alkali stress treatments. The relative expression levels of GhSOS1 and GhAKT1 genes under three types of saline-alkali stresses were alkali＞salt＞mixed saline-alkali stress. With the increase of soil salinity and pH value, the relative expression of GhNHX1 gene increased first and then decreased. The expression levels of GhNHX1 gene were salt＞alkali＞mixed salt-alkali stress. [Conclusion] Due to high salinity and pH value, mixed salt-alkali stress significantly inhibits cotton growth and ions uptake, which restricts the transport of P, K, Ca, Mg, Zn, Mn and Fe. The decrease of K and Na regulation ability leads to ions imbalance.     

短期NaCl与Na2CO3胁迫对紫花苜蓿种子萌发可恢复性的影响

探讨短期钠盐胁迫对紫花苜蓿种子萌发特性的影响。试验共设盐分类型、盐分浓度、温度及胁迫时间等4个因子,测定发芽率（势）等指标。结果表明：短期钠盐胁迫解除后,30℃发芽率最低,但温度无持续效应,前期温度仅影响前3天发芽,而不影响后期发芽;Na2CO3具有持久的抑制效应,各个测定指标均低于NaCl;随盐分浓度提高,发芽率逐渐降低,尽管250 mM显著抑制前3天发芽,但第5天该处理有显著恢复性萌发,表明盐分浓度为暂时性抑制效应;胁迫时间与盐分浓度效应类似,随胁迫时间延长,发芽率逐渐下降,30 h抑制前3天萌发,但胁迫解除后有较高的恢复萌发。     

基于灰色理论的食用型向日葵杂交品种主要性状分析

为改良河西地区食用型向日葵品种,采用灰色关联度分析法对8个食用型向日葵品种的10个农艺性状分别与产量、品质、发病率进行灰色关联度分析。结果表明生育期和茎粗是影响子实粗蛋白含量的主导因子；子实形状是影响子实粗脂肪含量的主导因子,同时子实的宽、长也是影响子实油酸、亚油酸含量的主导因子；子仁率和生育期是影响植株发病率的主导因子；百粒重和盘径是影响产量的主导因子。以上几个指标可以作为河西地区选择食用型向日葵品种的参考指标, 为科学合理的选择食用型向日葵品种, 保证食用型向日葵品质提供参考。     

混合盐碱胁迫对小麦种子萌发的影响

利用NaCl、Na2SO4、NaHCO3和Na2CO3四种盐模拟盐碱胁迫对小麦种子萌发的影响.试验表明,小麦种子在萌发过程中,受到环境pH值的直接影响不大,随着离子浓度的增加,以及碱性盐离子CO32-和HCO3-比例的升高,种子吸水能力减弱,生长量减少,发芽势、发芽指数和活力指数降低,种子发芽率降低.抗旱能力强的品种克旱16种子萌发忍耐盐碱胁迫的能力强于喜肥水的品种龙麦26.     

Vigour/tolerance trade‐off in cultivated sunflower (Helianthus annuus) response to salinity stress is linked to leaf elemental composition

Developing more stress‐tolerant crops will require greater knowledge of the physiological basis of stress tolerance. Here, we explore how biomass declines in response to salinity relate to leaf traits across 20 genotypes of cultivated sunflower (Helianthus annuus). Plant growth, leaf physiological traits and leaf elemental composition were assessed after 21 days of salinity treatments (0, 50, 100, 150 or 200 mM NaCl) in a greenhouse study. There was a trade‐off in performance such that vigorous genotypes, those with higher biomass at 0 mM NaCl, had both a larger absolute decrease and proportional decrease in biomass due to increased salinity. More vigorous genotypes at control were less tolerant to salinity. Contrary to expectation, genotypes with a low increase in leaf Na and decrease in K:Na were not better at maintaining biomass with increasing salinity. Rather, genotypes with a greater reduction in leaf S and K content were better at maintaining biomass at increased salinity. While we found an overall trade‐off between sunflower vigour and salt tolerance, some genotypes were more tolerant than expected. Further analysis of the traits and mechanisms underlying this trade‐off may allow us to breed these into high‐vigour genotypes in order to increase their salt tolerance.     

复合盐碱胁迫对韭菜种子萌发的影响

为了探讨复合盐碱对韭菜种子萌发的影响和韭菜栽培的盐碱适应能力,本试验采用不同浓度的氯化钠、硫酸钠、碳酸氢钠、碳酸钠混合液对韭菜种子萌发进行试验,来测定25种复合盐碱胁迫条件下韭菜种子的萌发率、萌发指数、胚轴长度和恢复萌发率等生长指标。结果表明：随着盐碱胁迫的增强,韭菜种子的萌发率、萌发指数均明显低于对照,但同一pH、不同盐浓度下种子萌发率的下降幅度要大于同一盐浓度、不同pH下的处理;将未萌发的种子转移至蒸馏水中复水后,高盐浓度和高pH最终萌发率只有最高萌发率的24.7%,延缓了种子的萌发,也抑制了一些低活力种子的萌发,萌发恢复率随着盐浓度的增加而增加;盐浓度、pH及其相互作用对韭菜种子萌发有抑制作用,其中盐浓度是决定性的主导因素。     

大棚辣椒营养生长的动态变化及其与温光因子的相关研究

以4个辣椒品系为材料,研究了塑料大棚栽培下辣椒营养生长的动态变化及温光对其营养生长的影响。结果表明：除了个别品系的根系体积指标外,其余各品系辣椒的营养生长指标间及与温光因子间相关显著或极显著;各指标与大棚温光因子间都有一个最佳的拟合曲线方程。