淋洗对盐胁迫下大豆生长和矿质营养基因型差异的研究

植物质外体是由细胞壁的纤维素和微晶体空间以及充满空气的细胞间隙组成 ,约占植物体积 5 %的空间。很久以来 ,质外体被认为是无生命的 ,与有生命的原生质相比很少引起研究者的兴趣 ,直到 80年代中期 ,由于研究技术的发展和研究的深入[1 ] ,对质外体的认识才发生根本性的转变 ,     

盐胁迫下大气CO2浓度升高对黄瓜幼苗生长、光合特性及矿质养分吸收的影响

采用营养液培养和开顶箱法,研究了盐胁迫下CO2浓度升高对黄瓜幼苗生长、光合特性及矿质养分吸收的影响。结果表明,黄瓜生长在80mmol/L NaCl下,其生物量、光合速率、气孔导度、蒸腾速率均显著下降,而胞间CO2浓度明显升高;CO2浓度升高可增加盐胁迫下黄瓜幼苗生物量,使光合速率、气孔导度、蒸腾速率升高。表明CO2浓度升高能减轻盐胁迫对光合功能的不利效应。80mmol/L NaCl可使黄瓜幼苗体内总N和K 的浓度降低,而使Na 浓度增加;CO2浓度升高具有提高盐胁迫下总N和K 浓度,降低Na 浓度的效应,说明CO2浓度升高可减轻盐胁迫的毒害作用,提高黄瓜幼苗生物量。     

硅对盐胁迫下黄瓜幼苗生长和矿质元素吸收的影响

采用幼苗水培实验,研究外源硅对盐胁迫下黄瓜幼苗生长过程中吸收某些矿质元素的影响。对植株地上部和地下部各元素的分析表明,盐胁迫条件下,外源硅有效调节了黄瓜根系对Na+、Ca2+、K+的吸收以及向地上部的转运。适量的硅降低了黄瓜根系从介质中吸收Na+量,并减少其向地上部的运输,而增加了植株体对K+、Ca2+的吸收和转运量,有效缓解了Na+对黄瓜植株体造成的盐胁迫伤害,保证了黄瓜幼苗的正常生长。在相同的处理条件下,盐分敏感品种的Na+在根系和地上部累积量都要比耐盐品种高,而K+的积累量却正好相反,这可能是耐盐品种减轻盐害的主要方式。对其它营养元素的研究表明,施硅抑制了对N素的吸收,对P素的吸收则影响不大。     

NaCl胁迫下甜瓜幼苗离子吸收特性研究

以厚皮甜瓜黄河蜜和薄皮甜瓜白沙蜜为试材,在人工控制条件下,研究了NaCl胁迫对甜瓜幼苗Na+、K+、Ca2+和Cl-吸收与分配的影响。结果表明,随NaCl浓度的增加,两个甜瓜品种各器官中Na+和Cl-含量均逐渐增加,K+含量逐渐减少,叶片中Ca2+含量逐渐降低,而根中的 Ca2+含量逐步增加;各器官中Na+/K+和叶片中Na+/ Ca2+逐渐增加;SK、Na 和SCa、Na逐步下降。NaCl胁迫下,黄河蜜叶片和茎中Na+ 积累和叶、茎、根中Cl-积累及K+ 、Ca2+ 降低幅度均明显低于白沙蜜;黄河蜜对K+ 和Ca2+的选择吸收和运输能力受胁迫的影响小于白沙蜜。表明厚皮甜瓜黄河蜜比薄皮甜瓜白沙蜜具有更强的耐盐性和盐适应性。     

基质栽培甜瓜矿质营养吸收规律的研究

以温室基质栽培的网纹甜瓜'甜甜1号'为试材,探讨了植株的干物质积累和矿质元素的吸收规律。结果表明,温室内基质栽培网纹甜瓜的生育期为100天,采收时植株总生物量为136g时,单株矿质元素的需求总量为11 09g。营养生长期和结果中期是植株干物质积累的两个重要时期(营养生长期1.27gplant-1d-1、结果中期2.19gplant-1d-1),应增施肥料,以满足植株快速生长的需要。甜瓜对矿质元素N、P、K、Ca、Mg需求的比例,营养生长期为41∶4∶32∶19∶4,结果中期为28∶5∶37∶25∶6。甜瓜的P需求量在结果前期最大(15 55mgplant-1d-1),N、K、Ca、Mg的需求量在结果中期最大,N为52.58mgplantd、K为82.33mgplant-1d-1、Ca为54.59mgplant-1d-1、Mg为12.42mgplant-1d-1。     

NaCl胁迫下作物对离子的吸收及分配

盐渍化土壤在世界上分布广泛,在我国也有很大的面积。为了开发利用盐渍化的土地资源,传统的治理途径是采用工程和农业措施相结合的方法。然而,近年来越来越多的研究表明,发掘利用现有的生物资源,应用现代生物技术,通过培育抗盐品种来提高植物抗盐性也是开发利用盐碱土的一个重要方面。本文通过对作物耐盐品种和盐敏感品种的比较,综述了盐胁迫下粮食、果树、蔬菜及棉花等作物对K+、Na+、Ca2+、Mg2+等离子吸收及分配的影响,并提出了进一步的研究方向。     

外源一氧化氮对镉胁迫下长春花质膜过氧化、ATPase及矿质营养吸收的影响

重金属污染已成为全球范围的主要问题之一,其中土壤镉（Cd）污染已成为当今社会普遍关注的问题。镉是植物生长发育的非必需元素,极小浓度即可产生较大危害。一氧化氮（NO）是一种氧化还原信号分子和活性氮（RNS）, 参与植物对重金属镉胁迫的应答。长春花（Catharanthus roseus）是我国广泛栽培的兼具园林绿化和抗癌药源等有重要价值的多年生草本花卉植物。为了解镉胁迫下外源NO 对园林地被植物生理响应的调控机制,采用盆栽试验研究了外源NO（硝普钠SNP）对镉胁迫下长春花幼苗生长、 活性氧代谢、 质膜ATPase酶和5'-核苷酸酶活性以及矿质营养元素吸收的影响。结果表明, 25 mg/kg 镉胁迫严重抑制长春花幼苗的生长,显著增加地上部和根系镉的富集量,抑制对大量元素和微量元素的吸收。施加0.45、 0.90、 1.80 mg/kg 的SNP显著降低镉从根系向地上部的转运,缓解因镉胁迫对钾（K）、 钙（Ca）、 镁（Mg） 和 铁（Fe）、 铜（Cu）、 锌（Zn） 吸收产生的抑制效应,降低镉胁迫的毒害作用,促进植物生长。镉胁迫下,丙二醛（MDA）含量和活性氧（O2和H2O2）水平显著升高。施加低浓度 SNP 能够显著缓解细胞质膜过氧化,降低硫代巴比妥酸反应产物（TBARS）堆积,且对抗氧化酶和ATPase酶具有相同作用。添加0.45、 0.90、 1.80 mg/kg 的SNP 可提高镉胁迫下长春花地上部和根系的抗氧化酶［过氧化氢酶（CAT）、 超氧化物歧化酶（SOD）、 过氧化物酶（POD）］活性与抗氧化物（还原型谷胱甘肽GSH）含量,诱导质膜H+-ATPase、 Ca2+-ATPase和 5-AMPase 活性提升到正常水平（对照CK）。添加1.80 mg/kg 的SNP对镉毒害的缓解作用最有效,而添加3.60、 7.20 mg/kg 的SNP的处理则无明显效果。     

蒸发脱湿过程中盐胁迫对苜蓿生长及矿质元素吸收运输的影响

用土壤溶液浓度ＮａＣｌ７５　～３２５　ｍｍｏｌ／Ｌ的中性盐对苜蓿　进行胁迫处理，研究苜蓿在土壤脱湿过程中，盐胁迫对其生长及矿质元素吸收运输的影响．　结果表明，ＮａＣｌ胁迫浓度的增加和胁迫时间的延长均使苜蓿的相对生长速率、含水量、累积　蒸散量、水分利用效率、Ｋ含量和Ｋ／Ｎａ值下降，但土体中的剩余水量却呈上升趋势．苜蓿生长　受到水分与盐分胁迫双重胁迫的影响．随ＮａＣｌ胁迫的增加，苜蓿的Ｎ素含有率变化不大，但积　累量显著减少；Ｋ＋、Ｃａ２＋的比吸收率（ＳＡＲ）显著降低，植株Ｋ＋、Ｃａ２＋含　量减少，而植株Ｎａ＋、Ｃｌ－的比吸收率ＳＡＲ显著提高，牧草体内Ｎａ＋、Ｃｌ－含量不断积　累增加，植株Ｋ／Ｎａ值降低．对Ｐ、Ｍｇ２＋的吸收在不同水盐条件下变化不一致．苜蓿根系　吸收钾钠离子后，向茎叶运输钾的选择性随ＮａＣｌ胁迫的不同而呈现出不同的趋势．     

高铝低磷胁迫对胡枝子生长及矿质元素吸收的影响

限制酸性土壤作物生长的最重要、最普遍的因子是Al3+ 的毒害和 P 的缺乏.本文用溶液培养试验研究两种不同生态型的二色胡枝子在高Al低P胁迫下的矿质营养元素积累情况.试验表明,江西胡枝子比河北胡枝子更耐低 P 低 pH 的生长环境,但两者间耐Al性无显著差异;100 μm/L Al 处理显著地抑制了两种胡枝子对 Ca 的吸收,降低了根系 Mg 的积累量,对植株的 K、P、Fe、Zn、Cu 含量没有显著影响;低 P 处理没有显著降低两种胡枝子对 Ca、K、Fe、Zn、Cu 和江西胡枝子对 Mg 的吸收,但是低 P 处理显著降低了河北胡枝子对 Mg 的吸收和转运.二色胡枝子植株吸收的 Al 主要积累在根部,地上部分Al含量仅是根系的1% 左右.     

低钾胁迫对水稻苗期矿质营养吸收和植物激素含量的影响

以水稻（Oryza sativa L.）受体N27（对照）和来源于N27的耐低钾基因型水稻N18和N19为材料。采用溶液培养技术研究了低钾胁迫对其苗期矿质营养吸收和叶片植物激素含量的影响。结果表明,在低钾胁迫下,水稻幼苗吸钾效率和钾利用效率以及植株钾转运率降低,但N18、N19的降低幅度小于N27。同时,低钾胁迫下N18和N19与N27相比具有较强吸收和运输钠、磷、镁、铁和钙的能力。低钾胁迫使水稻叶片IAA、GA1和ZR的含量以及IAA/ABA、ZR/ABA和GA1/ABA比值均降低,N18、N19的降低幅度小于N27,且具有较高的IAA、GA1和ZR的含量以及IAA/ABA、ZR/ABA和GA1/ABA比值;低钾胁迫下N18、N19叶ABA的含量增加幅度小于N27。水稻耐低钾特性与其矿质营养吸收能力和植物激素水平或植物激素间比例关系有关。     

盐胁迫下琯溪蜜柚苗木生理生化特性的变化研究

水培试验研究了不同浓度盐胁迫下琯溪蜜柚苗木生理生化特性的变化。结果表明,盐胁迫下溪蜜柚苗木根系活力、叶片相对含水量(RWC)、叶片细胞汁液pH、光合色素含量及氨基酸含量降低,大分子渗漏值及丙二醛(MDA)含量增加,且它们之间均呈显著和极显著相关性。琯溪蜜柚植株根系活力及叶片MDA含量对盐胁迫较敏感,根系活力下降可能是柚植株受盐胁迫后最早的伤害反应。     

Effects of salt stress on plant growth characteristics and mineral content in diverse rice genotypes

ABSTRACT

When rice is grown under moderate salinity (6?dS m^?1), yields are reduced by up to 50%. The development of salt-tolerant varieties is a key strategy for increasing yields. We conducted an experiment using a hydroponic system with ion components similar to seawater to determine useful parameters for assessing salt tolerance. Two-week-old seedlings were grown for 7 days on Yoshida hydroponic solution. The treatment group then additionally received an artificial seawater solution (electrical conductivity, 12 dS m^?1). After a 2-week period of salt stress, standard evaluation scores (SES) of visual salt injuries were assessed. The K, Na, Mg, and Ca contents were then determined in the roots, sheaths, and leaves of each plant. Following the SES results, we divided the 37 genotypes into four groups: salt-tolerant groups (STGs), moderately salt-tolerant groups, salt-sensitive groups (HSSGs), and highly salt-sensitive groups (HSSGs). In the control, STGs had the highest sheath K content (30.1 mg g^?1 dried weight [DW]), whereas HSSGs had the lowest (21.4 mg g^?1 DW). Sheath K was also highly and negatively correlated with SES. This suggests that sheath K may be useful for identifying salt-tolerant varieties under non-saline conditions. Plant growth was significantly affected under salt stress, but STGs had the smallest decrease in sheath DW. SES was significantly correlated with sheath and leaf Na, sheath K and Mg, and sheath and leaf Na/K and Na/Mg ratios. The results suggested that sheath K, Na/K, and Na/Mg may be useful indicators for genetic analyses of salt-tolerant varieties under salt-stress conditions. The salt-tolerant cultivars, KCR20, KCR124, and KCR136, are possible candidates for such studies because they had high sheath K content (31.19, 31.21, 29.44 mg g^?1 DW, respectively) under non-saline conditions and low SES (3.3, 3.6, 3.9, respectively), and low sheath Na/K (0.64, 0.52, 0.92, respectively) and Na/Mg ratios (2.96, 2.27, 3.03, respectively) under salt-stress conditions.     

Effect of grafting on the growth and ion concentrations of cucumber seedlings under NaCl stress

Abstract

To assess whether grafting raised the salt tolerance of cucumber seedlings by limiting transport of Na⁺ to the leaf and to test whether the salt tolerance of grafted plants was affected by the shoot genotype, two cucumber cultivars (“Jinchun No. 2”, a relatively salt-sensitive cultivar, and “Zaoduojia”, a relative salt-tolerant cultivar) were grafted onto rootstock pumpkin (Cucurbita moschata Duch. cv. “Chaojiquanwang”, a salt-tolerant cultivar). Ungrafted plants were used as controls. The effects of grafting on plant growth and ion concentrations were investigated under NaCl stress. Reductions in the shoot and root dry weights, leaf area and stem diameter of grafted plants were lower and concentrations of K⁺ and Cl^? in the leaves were higher than those of ungrafted plants under the same NaCl stress. The Na⁺ concentration and Na⁺/K⁺ ratio in scion leaves and in the stems of grafted plants were lower, whereas those in rootstock stems and roots were higher than in ungrafted plants under the same NaCl stress. Shoot and root dry weight, leaf area and stem diameter were negatively correlated with leaf Na⁺ concentrations and Na⁺/K⁺ ratio, but were positively correlated with leaf K⁺ concentrations. The Na⁺ concentrations and Na⁺/K⁺ ratio were lower, whereas the K⁺ concentrations in the leaves of grafted “Zaoduojia” plants were higher than those in grafted “Jinchun No. 2” plants under the same NaCl stress. The reductions in leaf area and stem diameter of grafted “Jinchun No. 2” plants were more severe than those of grafted “Zaoduojia” plants. These results indicate that: (1) the higher salt tolerance of grafted cucumber seedlings is associated with lower Na⁺ concentrations and Na⁺/K⁺ ratio and higher K⁺ concentrations in the leaves, (2) grafting improved the salt tolerance of cucumber seedlings by limiting the transport of Na⁺ to the leaves, (3) the salt tolerance of grafted cucumber seedlings is related to the shoot genotype.     

Seed vigor and boron and calcium nutrition influence oilseed rape germinability and seedling growth under salt stress

The beneficial effects of boron (B) and calcium (Ca) nutrition on pea seed germinability under salinity stress have recently been shown. However, nothing is known about the influence of seed vigor status on these results, especially in oilseed rape as an important oil crop worldwide. Therefore, an experiment was conducted to investigate the effects of seed vigor, boron and calcium nutrition on seed germinability, seedling growth, and some biochemical characteristics of oilseed rape seedlings under salinity. In spite of promotive effects of application of both boron and calcium nutrition on oilseed rape germinability and seedling growth, there was a more significant promotion on germination rate of high vigor seeds. Proline content and guaiacol peroxidase activity of seedlings were significantly increased by adding supplemental boron to the medium compared to the control. Finally, it can be concluded that boron and calcium nutrition would improve the salt tolerance capability of oilseed rape seedlings from vigorous seeds, at least in the early plant development.     

盐胁迫环境下接种根际促生细菌对碱蓬根际土壤微环境特征的影响

为探讨不同盐胁迫生境中接种根际促生细菌(PGPR)对碱蓬根际土壤微环境特征的作用效果,通过盆栽试验,研究了不同盐胁迫(轻度、中度、重度)及其接种蜡样芽孢杆菌(PGPR)对碱蓬根际土壤中根系分泌物含量、微生物数量、微生物多样性及根系吸收面积的影响。结果表明:与对照相比,轻度盐胁迫下碱蓬根系分泌物中的有机酸总量、氨基酸总量、微生物量碳和氮含量及根系总吸收面积变化较小,微生物数量和根体积、根系活跃吸收面积显著下降,而中度、重度盐胁迫使上述指标均明显下降,且降幅随着盐胁迫梯度的增加而增大;当接种PGPR后,碱蓬根系分泌物中的有机酸总量、氨基酸总量、微生物数量和微生物量碳、氮含量以及根系总吸收面积、活跃吸收面积均呈上升趋势,其中轻度盐胁迫接种PGPR处理的上述指标均最高,并显著高于其他处理,且有机酸总量、细菌数、根系总吸收面积和活跃吸收面积分别显著高于CK 14.57%、12.80%、8.33%和28.24%。此外,轻度盐胁迫接种PGPR处理的微生物多样性指数最高,依次为对照、轻度、中度和重度盐胁迫处理,这与微生物总量的变化规律一致;而中度或重度盐胁迫接种PGPR处理的微生物多样性指数与微生物总量的变化趋势不一致。综上,轻度盐胁迫(盐分含量10.0 g/kg)下接种蜡样芽孢杆菌能显著改善碱蓬根际土壤的微环境特征,其影响效果显著优于中度或重度盐胁迫下接种蜡样芽孢杆菌。     

外源亚精胺对盐胁迫下黄瓜幼苗活性氧代谢的影响

采用营养液水培，研究了盐胁迫下外源亚精胺(Spd)对抗盐能力不同的2个黄瓜品种幼苗叶片和根系内活性氧(ROS)水平和抗氧化酶活性的影响。结果表明，外源Spd降低了50 mmol/L NaCl胁迫下幼苗体内O^-.₂产生速率、H₂O₂和丙二醛(MDA)含量，提高了抗氧化酶SOD、POD和CAT的活性；与抗盐性较强的“长春密刺”品种相比，Spd处理对抗盐性较弱的“津春二号”品种效果更明显。表明外源Spd处理通过促进盐胁迫下植株体内抗氧化酶活性的提高，降低ROS水平，从而缓解NaCl对黄瓜幼苗的盐伤害。