节节麦小穗上不同粒位种子萌发对环境因子的响应

为明确节节麦小穗上不同粒位种子萌发对环境因素的响应差异, 采用培养皿法测定了小穗基部小花形成的第1粒种子(S1)和相邻上部位置小花形成的第2粒种子(S2)萌发对酸碱胁迫?盐胁迫和水分胁迫的响应?结果显示:S1和S2萌发均对pH要求不高, 但在供试pH为3~10时, S2的萌发速率大于S1?与S1相比, S2萌发具有较强的耐盐性, 在不同盐浓度下, S2发芽率相对较高, 而S1的发芽率随着盐浓度的升高显著降低?此外, 盐胁迫对S1和S2的萌发速率有一定影响, 两者的萌发速率均随着盐浓度的升高而降低, 但S2较S1萌发快?水分胁迫对节节麦S1和S2萌发均有抑制作用, 但S2萌发对水分胁迫的耐受性显著高于S1, 在渗透势为-1.28~-0.69 MPa时S1的发芽率达到最大发芽率的50%, 而S2在渗透势为-1.75~-1.56 MPa时发芽率达到最大发芽率的50%?此外, S1和S2的萌发速率均随着渗透势的下降而降低, 但S2的萌发速率大于S1?以上结果表明, 节节麦种子萌发过程中第2粒位种子S2比第1粒位种子S1更具有耐受环境胁迫的能力?     

恶性杂草马齿苋（Portulaca oleracea）种子萌发特性的研究

为了明确恶性杂草马齿苋种子的萌发特性,本文研究了温度、光照、pH、水势、盐分及土层深度对其种子萌发的影响。结果表明：马齿苋种子在光照L∥D=14 h∥10 h、温度白天32 ℃,晚上28 ℃的变温条件下萌发率最高,为92%。马齿苋种子萌发适宜的酸碱度范围较宽,在5相似文献   

盐和PEG模拟干旱胁迫对沙米种子萌发及幼苗生长的影响

研究不周浓度盐溶液(NaCl、MgSO4、盐渍土壤)和PEG模拟干旱胁迫对沙米种子吸胀、萌发和幼苗生长的影响,并观察胁迫解除后种子的反应.结果表明:随着NaCl、MgSO4和PEG浓度的升高,沙米种子吸胀率先升后降,种子萌发率呈现不同程度降低,盐渍土壤溶液对萌发率没有显著影响;对沙米种子萌发和幼苗生长的胁迫效应是NaC...     

不同环境因素对节节麦萌发的影响

节节麦Aegilops tauschii Coss.是麦田难治杂草,研究环境条件对节节麦发芽的影响对预测其适生区域及综合治理有重要意义。以采自陕西、山东和河南的3个节节麦种群为对象,通过室内和室外萌发试验研究了水势、pH、盐分和播种深度与节节麦萌发的关系。结果表明,3个节节麦种群在不同的环境条件下表现出相似的萌发及出苗特性,其萌发对水势敏感,发芽率随水势的下降而降低,当渗透势小于-1.0 MPa时,种子不萌发;节节麦萌发对pH要求不高,在pH 3～10条件下发芽率均超过70%;其萌发具有一定的耐盐性,盐浓度为0 mmol/L时,发芽率最高,盐浓度大于420 mmol/L时,节节麦不能萌发;节节麦出苗率随播种深度的增加而降低,播种在土壤表面时,出苗率最高,播种深度大于10 cm时,未发现节节麦出苗。3个节节麦种群发芽对上述不同环境因子的反应差异不显著。     

鹅观草种子萌发及出苗特性

在实验室和温室条件下研究不同温度、光照、水势、盐分对鹅观草种子萌发以及埋土深度对鹅观草出苗的影响。结果表明,鹅观草种子萌发的昼/夜温度范围为20℃/10℃~35℃/25℃,最适昼/夜温度为25℃/15℃;黑暗条件下,鹅观草种子萌发率较光照下略有提高,说明鹅观草萌发不需要光照;鹅观草种子对水势胁迫较敏感,水势从0下降至-0.8 MPa时,发芽率从93%直线下降至0;鹅观草种子对盐分胁迫具有一定耐受性,当NaCl浓度≤50 mmol/L时,种子均能保持80%以上的萌发率。50%萌发抑制率时的水势和NaCl浓度分别约为-0.4 MPa和100 mmol/L。埋土深度为0.5 cm时,鹅观草出苗率最高,埋土深度≥3 cm时出苗率显著下降。表明鹅观草种子萌发具有较强的环境适应性,通过耕作将其种子带入4 cm以下土层,可有效抑制鹅观草的危害。     

Maternal salinity improves yield,size and stress tolerance of Suaeda fruticosa seeds

Shrubby seablite or lani(Suaeda fruticosa Forssk)is a perennial euhalophyte with succulent leaves,which could be planted on arid-saline lands for restoration and cultivated as a non-conventional edible or cash crop.Knowledge about the impacts of maternal saline environment on seed attributes of this important euhalophyte is lacking.This study investigated the effects of maternal salinity on yield,size and stress tolerance of S.fruticosa seeds.Seedlings of S.fruticosa were grown in a green net house under increasing maternal salinity levels(0,300,600 and 900 mM NaCl)until seed production.Total yield,size,stress tolerance and germination of the descended seeds under different maternal saline conditions were examined.Plants grown under saline conditions(300,600 and 900 mM NaCl)produce a substantially higher quantity of seeds than plants grown under non-saline condition(0 mM NaCl).Low maternal salinity(300 mM NaCl)improves seed size.Seeds produced under all maternal salinity levels display a higher tolerance to low temperature(night/day thermoperiod of 10℃/20℃),whereas seeds produced under 300 mM NaCl maternal saline condition show a better tolerance to high temperature(night/day thermoperiod of 25℃/35℃)during germination.Seeds from all maternal saline conditions germinate better in the 12 h photoperiod(12 h light/12 h dark)than in the dark(24 h dark);however,seeds produced from low and moderate maternal saline conditions(300 and 600 mM NaCl)show a higher germination in the dark than those from control and high maternal saline conditions(0 and 900 mM NaCl).In general,maternal salinity is found to improve yield,size and stress tolerance of S.fruticosa seeds.     

不同环境因素对猪殃殃种子萌发及出苗的影响

为探讨猪殃殃种子萌发的适宜环境条件,通过室内萌发试验研究了温度、光照、pH、水势、盐分对猪殃殃种子萌发以及埋土深度对其出苗的影响。结果表明,猪殃殃种子萌发的适宜环境条件为温度10~20℃、光暗12h交替培养以及pH 4~10,萌发率可达到50%以上。猪殃殃种子对水势比较敏感,萌发率随着水势的降低而降低,当水势为0时,萌发率为50.50%,水势降低至-0.6 MPa时,仅有个别种子萌发,萌发率为3.50%,当水势为-0.7 MPa时,种子萌发完全受到抑制;猪殃殃种子对盐分胁迫有一定忍耐力,当NaCl浓度为0.16mol/L时,仍有少数种子萌发,萌发率为16.50%;适于猪殃殃种子出苗的埋土深度是1~2cm,出苗率达到49.50%。研究结果为猪殃殃的出苗调控和综合治理提供了依据。     

Effect of the burial depth and environmental factors on the seasonal germination of bearded sprangletop (Leptochloa fusca [L.] Kunth ssp. fascicularis [Lam.] N. Snow)

Bearded sprangletop recently was introduced to Turkey, where it has adapted to rice cultivation and become an important weed in many regions of the country. Experiments were conducted to determine the effects of light, temperature, osmotic stress, salt stress, pH and flooding on bearded sprangletop germination and emergence. Mature bearded sprangletop seeds were collected from rice fields in August 2008. Approximately 1250 seeds were wrapped in plastic fabric and buried at 2 or 10 cm in pots in flooded or non‐flooded conditions. In this experiment, seed germination in the light from the flooded and non‐flooded treatments began in the spring, peaked in summer and decreased in the fall. This pattern was repeated the following year after exposing the seeds to natural seasonal temperature changes. As either the level of water stress or NaCl concentration increased, cumulative seed germination decreased. No seed germinated when the NaCl concentration exceeded 400 mole. The level of seedling emergence decreased with an increasing burial depth. Under the flooded conditions, emergence began in late April and continued until early July, with peak emergence in the first week of June. Under the non‐flooded conditions, bearded sprangletop emerged later than under the flooded conditions and the overall level of emergence was lower. The depth of burial and water stress appear to be the most important factors that limit seed germination. Germination was stimulated by light, suggesting that the seeds are positively photoblastic.     

温周期、贮藏时间和盐分对短毛柽柳种子萌发的影响

短毛柽柳(Tamarix karelinii)是分布于盐渍化沙地和重盐碱地的灌木。为了阐明短毛柽柳种子的萌发特性,设置不同的温周期、储藏时间和盐分梯度,采用室内控制实验研究这些因子对种子萌发的影响。结果表明:1短毛柽柳种子在4个温周期中均具有高的萌发率,并且温周期温度越高,种子的萌发速率越快。2室温贮藏1个月显著提高种子的萌发速率,在贮藏6个月内,种子的最终萌发率都能达到100%。3≤0.8 mol·L~(-1)的Na Cl溶液对种子的最终萌发率无显著影响,而≥1.0 mol·L~(-1)的溶液则抑制种子的萌发,且随着浓度的增加,种子的最终萌发率呈下降趋势,直至为0。将1.0~4.0 mol·L~(-1)溶液中没有萌发的种子,转移至蒸馏水继续培养后,仍有71.67%~28.00%的种子恢复萌发率,表明种子具有较强的耐盐性。对短毛柽柳种子萌发特性的研究,为短毛柽柳的种苗培育提供基础资料。     

盐旱耦合胁迫对费尔干猪毛菜种子萌发及其幼苗生长的影响

本研究采用双因素组合实验,探讨盐(NaCl)、干旱(PEG 6000)对费尔干猪毛菜(Salsola ferganica)种子萌发和幼苗生长的影响。结果显示:①费尔干猪毛菜种子萌发能耐受较高浓度NaCl和PEG胁迫。低浓度NaCl或PEG胁迫下,费尔干猪毛菜去翅种子和具翅种子萌发率与对照无显著差异,高浓度NaCl或PEG处理下,去翅种子萌发率35%以上,显示较强的耐盐、耐旱性;盐旱耦合处理下,不同低浓度PEG能够显著缓解中浓度NaCl对种子萌发的抑制作用。②随NaCl浓度升高,具翅种子恢复萌发率逐渐上升,而去翅种子则维持较低水平;随着PEG浓度的升高,2种种子恢复萌发能力显著降低;盐旱耦合处理下2种种子的恢复萌发率与NaCl胁迫具有相同趋势。③NaCl或PEG对去翅种子幼苗的影响比具翅种子强,特别是PEG处理;随NaCl或PEG浓度升高,2种种子幼苗的株高和根长均降低;盐旱耦合处理下低浓度NaCl对去翅种子幼苗的影响比具翅种子小(除了100 mmol·L^-1NaCl+25 g·L^-1PEG处理),中浓度NaCl对去翅种子幼苗的影响比具翅种子强,高浓度NaCl处理下随PEG浓度升高,2种种子幼苗的株高和根长均降低。以上结果显示,费尔干猪毛菜在萌发期和幼苗期具有较强的耐盐耐旱性,盐旱耦合在一定程度上能够缓解盐离子毒害效应,这对其度过早期恶劣环境具有重要的生态学意义;果翅对种子在胁迫下进入次级休眠,从而补充土壤种子库起到重要作用。     

Germination, emergence, and dormancy of Mimosa pudica

Mimosa pudica (common sensitive plant) is a problematic weed in many crops in tropical countries. Eight experiments were conducted to determine the effects of light, seed scarification, temperature, salt and osmotic stress, pH, burial depth, and rice residue on the germination, seedling emergence, and dormancy of M. pudica seeds. Scarification released the seeds from dormancy and stimulated germination, though the germination of the scarified seeds was not influenced by light. The scarification results indicate that a hard seed coat is the primary mechanism that restricts germination. The germination increased markedly with the exposure to high temperature "pretreatment" (e.g. 150°C), which was achieved by placing non-scarified seeds in an oven for 5 min followed by incubation at 35/25°C day/night temperatures for 14 days. The germination of the scarified seeds was tolerant of salt and osmotic stress, as some seeds germinated even at 250 mmol L⁻¹ NaCl (23%) and at an osmotic potential of −0.8 MPa (5%). The germination of the scarified seeds was >74% over a pH range of 5–10. The seedling emergence of the scarified seeds was 73–88% at depths of 0–2 cm and it gradually decreased with an increasing depth, with no seedling emergence at the 8 cm depth. The rice residue applied to the soil surface at rates of ≤6 t ha⁻¹ did not influence the seedling emergence and dry weight. The information gained from this study identifies some of the factors that facilitate M. pudica becoming a widespread weed in the humid tropics and might help in developing components of integrated weed management practises to control this weed.     

蒙古扁桃种子萌发和幼苗生长对渗透胁迫的响应

以天然生长于祁连山自然保护区隆畅河自然保护站的濒危植物蒙古扁桃(Prunus mongolica)去内果皮的种子为材料,以不同渗透势PEG-6000溶液模拟干旱条件,研究了种子萌发和幼苗生长对干旱胁迫的响应特征。结果表明,随着干旱胁迫程度的加剧,蒙古扁桃种子吸胀速率、萌发率、萌发指数、活力指数、苗高和根长、组织饱和含水量等指标均表现出明显降低的趋势,而幼苗初生芽干重、根干重和根冠比均呈先升后降的趋势。蒙古扁桃种子对水势变化既敏感又抗旱,种子能够萌发的最低渗透势阈值为-0.65 MPa。干旱胁迫未能萌发的种子复水后萌发率较高。分析认为,蒙古扁桃种子萌发和幼苗生长对干旱胁迫的响应特征对种的延续具有重要意义,但在人工栽培时保证 土壤墒情应是保障建植成功的关键措施。     

Factors affecting seed germination and emergence of Aegilops tauschii

Information on seed germination and emergence ecology of Aegilops tauschii is scant, despite it being a widespread invasive weed in China. We conducted this study to determine the effects of various factors on seed germination and seedling emergence in three A. tauschii populations. Seeds germinated across a wide range of temperatures (5–35°C), with germination of over 90% at 15–20°C. Germination was completely inhibited when dry seeds were exposed to a temperature of 160°C for 5 min; a similar response was observed for pre-soaked seeds at 100°C. Light was neither required for nor inhibited germination. Germination was not significantly affected by pH. Aegilops tauschii was relatively tolerant to low osmotic potential and high salt stress: over 80% of seeds germinated at −0.3 MPa, and all three populations germinated in the presence of 400 mM salt (NaCl) although salt tolerance varied among the populations. Seeds buried at depths of 1–3 cm emerged well, but emergence was completely inhibited at depths greater than 8 cm. The addition of maize straw caused a linear reduction in seedling emergence, although the rate of reduction varied among the populations. The results of this study have contributed to understanding the requirements of A. tauschii germination and emergence and optimising an integrated management system for this weed in Huang–Huai–Hai Plain of China. In addition, our study provides data for development of models to predict the geographical distribution of this weed.     

精口恶唑禾草灵抗性及敏感菵草种群萌发条件的比较

为了比较对精口恶唑禾草灵抗性及敏感菵草种群在萌发特性上的差异,采用培养皿法研究了温度、光照、pH值、水势、盐胁迫对其萌发的影响。结果表明,pH值为4-10条件下,2个种群的萌发率无显著性差异;全光照条件下,抗性菵草的萌发率显著低于敏感菵草;10℃条件下,抗性菵草的萌发率显著低于敏感菵草;水势胁迫和盐分胁迫对抗性菵草萌发的影响大于敏感菵草,当水势为-0.5 MPa时,抗性菵草无萌发,敏感菵草萌发率为41.9%;当NaC l溶液浓度为160 mmol/L时,抗性菵草无萌发,敏感菵草的萌发率为51.7%。     

青海云杉种子萌发特性

以天祝县青海云杉天然种群种子为研究对象,通过对种子生活力测定,分析种子萌发对温度、光照、水分和盐分胁迫的响应,为引种提供参考数据。结果表明：① 种子的生活力为72%。② 在黑暗条件下,温度小于10 ℃种子不萌发,最适萌发温度25/15 ℃(72%);种子在24 h黑暗和24 h光照条件下的萌发率显著高于14 h光照/10 h黑暗。③ 当NaCl胁迫浓度为50 mmol·L^-1时,可促进种子萌发,当胁迫浓度大于50 mmol·L^-1时,抑制种子萌发;胁迫解除后,随着胁迫浓度的增加,恢复萌发率(RGR)先增加后减小,胁迫浓度为400 mmol·L^-1时,RGR达到最大值13%。④ 随着PEG-6000试剂胁迫渗透势的增加,种子萌发显著减少,在-0.9 MPa时,种子不能萌发;胁迫解除后,RGR先增加后减少,在-0.9 MPa时,达到最大值35%。     

Ni~(2+)、Cu~(2+)胁迫对柠条种子萌发特征的影响

干旱区矿业废弃地生态修复植物的科学选择是生态治理的前提。文中以干旱区生态恢复的优势植物柠条(Caragana korshinskii Kom)为研究对象,研究了Ni2+、Cu2+在不同浓度条件下对其种子萌发特征的影响,以期为矿业废弃地及重金属污染土壤的生态修复提供科学依据。结果表明:在Ni2+或Cu2+胁迫条件下,柠条种子的发芽率、发芽势、发芽指数及活力指数都有不同的响应特征,低浓度时对种子萌发影响不明显,甚至有促进作用,当Ni2+浓度为20mg/L或Cu2+浓度为50mg/L时柠条种子的萌发较快,发芽率相对较高,且有利于干物质的积累;高浓度时则有较强的抑制作用,其中Ni2+的抑制作用要高于Cu2+;Ni2+和Cu2+对胚根的生长均具有抑制作用并随着浓度的升高而逐渐增强。     

盐胁迫对不同基因型冬小麦发芽和出苗的影响

研究了不同浓度NaCl胁迫对4种不同基因型冬小麦种子发芽及出苗的影响。试验结果表明,50～150mmol/LNaCl处理对小偃6号和NR9405发芽的抑制作用较小,50、100mmol/LNaCl处理对陕229和RB6的发芽有一定促进作用;150～200mmol/L的盐浓度可能是影响小麦种子萌发的临界浓度。盐胁迫下,小麦种子发芽率、发芽指数及活力指数下降,且活力指数对盐害反应最为敏感。盐胁迫抑制小麦发芽期间芽和根生长,且在低盐浓度(50mmol/L)下根受抑制敏感程度大于芽;盐浓度上升则相反。小麦根数在低盐浓度(50mmol/L)下增加,高盐浓度(>150mmol/L)下减少。盐胁迫下,小麦种子出苗延迟,出苗率下降。不同基因型小麦发芽过程对盐胁迫的反应不同。小麦种子耐盐性存在基因型差异,4个冬小麦品种中,小偃6号种子耐盐性相对较好,NR9405次之。陕229和RB6耐盐性相对较差。     

种子引发对盐渍土壤条件下高粱芽苗生理特性的影响

为探索引发种子对不同盐渍土壤条件下高粱芽苗的生理效应,增强高粱芽苗期的耐盐能力,采用盆栽沙培试验,将氯化钠和硫酸钠复配引发(CSP)、氯化钠单独引发(SSP)和不引发(NSP)处理后的高粱种子分别播种在0、40、80、120 mmol·L-1和160 mmol·L-1盐溶液漫灌的细沙盐渍土壤条件下,研究上述各种状态下种子萌发和幼苗生理特性。结果表明:种子引发可提高盐胁迫下高粱的发芽率、成苗率和活力指数,尤其是盐复配引发(CSP)效果更为明显;引发后的种子(特别是CSP)可显著减少中、高盐胁迫条件下叶片和根系相对含水量的下降幅度,减缓叶绿素a+b、叶绿素a的下降;氯化钠和硫酸钠复配引发(CSP)下净光合速率在盐浓度低于80 mmol·L-1时下降幅度较小,气孔导度和蒸腾速率与之变化趋势基本一致;种子引发增强了SOD、POD、CAT和APX活性,同时减少了MDA和O·2,其中MDA、O·2和POD反应较为敏感,三种种子引发处理对高粱芽苗期抗氧化系统的影响效应表现为:复配引发(CSP)单盐引发(SSP)不引发(NSP)。盐渍土壤条件下种子引发,特别是氯化钠和硫酸钠复配引发种子可增强其生理适应性,进而提高高粱芽苗期的耐盐性。     

Seed germination ecology of creeping mannagrass (Glyceria acutiflora) and response to POST herbicides

Creeping mannagrass is a perennial grass weed widely distributed in China and is becoming increasingly problematic in nurseries and landscapes in some regions. Understanding the germination ecology and response to commonly available POST herbicides of this weed is critical to determining its adaptive capabilities and potential for infestation, and assist in the development of effective control strategies. In the light/dark regime, creeping mannagrass germinated over a wide range of temperatures (15/5 to 30/20°C), with maximum germination at 20/10°C (95%). No seed germinated at 35/25 or 10/0°C. The time required for 50% of maximum germination increased as temperature decreased. Compared with the light/dark conditions, germination was slightly stimulated when seeds were placed in the dark. Creeping mannagrass is moderately tolerant to osmotic and salt stress, which had 53 and 50% germination rates at ?0.6 mPa osmotic potential and 200 mM NaCl concentration, respectively. Seedling emergence of the seeds buried at a depth of 0.5 cm (86%) was higher than those sowing on the soil surface (17%), but declined with burial depth increasing. There were no differences in the emergence rates from a burial depth 0.5–2 cm. Few seeds (4%) could emerge when seeds were sowed at a depth of 8 cm. POST application of haloxyfop‐R‐methyl, quizalofop‐p‐ethyl, sethoxydim, and pinoxaden provides 100% control of creeping mannagrass at the three‐leaf to five‐leaf stages. To achieve 80% control with clodinafop‐propargyl, mesosulfuron‐methyl, and fenoxaprop‐p‐ethyl, herbicides had to be applied at the three‐leaf stage.     

Germination behaviour of Cenchrus pauciflorus seeds across a range of salinities

Cenchrus pauciflorus (field sandbur) is an annual weed native to South America and Africa that has become an invasive plant in farmland and pastures around the globe. It forms two types of seeds that are different in shape and mass, defined as big seeds (M) and small seeds (P). This study examined effects of salinity and seed type on germination efficiency of C. pauciflorus. Increased concentration of salinity solutions (NaCl, Na₂SO₄ and Na₂CO₃) reduced germination rate and final germination percentage (FGP) of both seed types, while prolonging the mean final germination time (T_FG). M seeds tolerated salinity levels below 400 mmol (NaCl), 350 mmol (Na₂SO₄) and 300 mmol (Na₂CO₃), while P seeds tolerated salinity levels below 350 mmol (NaCl), 250 mmol (Na₂SO₄) and 150 mmol (Na₂CO₃). Furthermore, M seeds were less sensitive than P seeds, confirmed via increased germination rate (61%, 42% and 40%), FGP (36%, 29% and 26%), and shorter T_FG (37%, 19% and 16%) in NaCl, Na₂SO₄ and Na₂CO₃ solutions respectively. Moreover, the germination threshold values of M and P seeds were 426 and 365 mmol for NaCl, 354 and 264 mmol for Na₂SO₄ and 308 and 149 mmol for Na₂CO₃ respectively. These results add to our understanding of the germination strategy of different seed types of C. pauciflorus. This information on germination ecology may indicate a potential to invade regions with little or no salt stress.