He-Ne激光处理对拟南芥种子萌发和幼苗生长特性的影响

以哥伦比亚生态型(Columbia-0)的野生型拟南芥为材料,利用He-Ne激光生物辐照仪(632.8nm,5mW/mm2)处理拟南芥种子,统计其发芽势和发芽率,并测定根长及叶绿素、可溶性糖、可溶性蛋白和丙二醛(MDA)的含量,以探讨He-Ne激光对拟南芥种子萌发和幼苗生长的影响。结果显示,短时间的He-Ne激光辐照可促进拟南芥的生长发育,且最佳辐照时间为4min,此时的发芽势、发芽率、根长、叶绿素、可溶性糖及可溶性蛋白的含量均达到最大,而丙二醛(MDA)的含量为最低。当辐照时间大于4min时,促进作用逐渐变小,且随着辐照时间的延长而表现出抑制作用。研究表明,适量的He-Ne激光辐照在一定程度上可以促进拟南芥种子的萌发和幼苗生长以及保护其细胞膜免受伤害。     

壳聚糖包衣对油菜种子萌发及幼苗耐盐性影响

以不同浓度的壳聚糖对油菜种子进行包衣处理,考察其对油菜种子萌发及幼苗耐盐性的影响,并在不同盐浓度胁迫条件下对种子萌发时的发芽势、发芽率、生物量（鲜重、干重、根长、芽长）等指标进行测定,同时分析油菜幼苗叶绿素含量、可溶性蛋白及可溶性糖含量的变化。结果表明,一定浓度的壳聚糖包衣处理可提高油菜种子发芽率、发芽势、生物量、幼苗的耐盐指数、叶绿素含量、可溶性蛋白及可溶性糖的含量,其中浓度为0.25 g·L^-1壳聚糖包衣处理对油菜种子萌发的促进效果较好,而浓度为0.50 g·L^-1壳聚糖包衣处理对提高油菜幼苗耐盐性具有较好的促进作用。     

云杉种子萌发和幼苗生长对气候变暖与UV B辐射增强的响应

采用开顶式有机玻璃罩(OTCs)及紫外灯分别模拟气候变暖和UV-B增强,对位于气候变暖和UV-B增强突出的青藏高原东缘的高山峡谷地云杉种子萌发、幼苗生长和光合色素含量的变化进行测定分析,探讨云杉对气候变暖和UV-B增强的响应机理。结果显示:(1)UV-B辐射增强对云杉种子萌发无显著影响,但显著抑制萌发幼苗的生长、降低其针叶叶绿素含量,并造成幼苗大量死亡(P<0.05)。(2)气候变暖使云杉种子提前萌发,并提高了发芽势、发芽率和发芽指数,促进幼苗生长和叶绿素的积累,显著降低幼苗死亡率(P<0.05)。(3)气候变暖缓解了UV-B增强对云杉萌发幼苗生长和叶绿素含量的抑制作用,并降低了UV-B胁迫下幼苗的死亡率。研究表明,在未来气候变暖和UV-B辐射增强同时存在时,气候变暖能够在一定程度上缓解UV-B增强对云杉林早期更新带来的抑制作用。     

外源5-氨基乙酰丙酸对盐胁迫下菘蓝种子萌发及幼苗抗氧化酶活性的影响

采用砂培方式,研究了外源5-氨基乙酰丙酸(ALA)对盐胁迫下菘蓝种子的萌发、幼苗叶片的可溶性糖含量、丙二醛(MDA)含量及其抗氧化酶活性的影响,探讨ALA缓解菘蓝受盐胁迫伤害的响应机制。结果显示:(1)菘蓝种子萌发及幼苗生长在100 mmol·L^-1 NaCl胁迫下受到明显的抑制,种子发芽率、发芽势、发芽指数、活力指数与自然含水量均显著降低,丙二醛含量、可溶性糖含量以及超氧化物歧化酶(SOD)、过氧化物酶(POD)活性显著升高。(2)盐胁迫下适宜浓度的ALA处理显著提高了种子萌发率、自然含水量及SOD、POD和CAT活性,降低了可溶性糖和丙二醛的含量,并以16.7 mg·L^-1 ALA处理盐胁迫下菘蓝种子的发芽率、发芽势最大,其幼苗的SOD、POD、CAT活性最强。研究表明,盐胁迫显著抑制菘蓝种子的萌发及幼苗生长,适宜浓度的ALA能够有效缓解盐胁迫对菘蓝种子萌发及幼苗生长的伤害,提高植株的抗盐性,并以16.7 mg·L^-1 ALA处理效果最佳。     

激光照射萌发的番茄种子的生物学效应的初步研究

将萌发的番茄(Lycopersicon esculentum)种子用不同时间(0、40、80、120、160、200、240 s)的He-Ne激光照射后,测定了种子的发芽势、发芽率和幼苗的生长量.待幼苗生长25 d后,取番茄叶片测定了细胞内叶绿素、可溶性糖、蛋白质和核酸的含量.结果显示,随着照射时间延长,种子的发芽势、...     

激光对小麦陈种子萌发和生长的影响

用不同剂量的He-Ne激光辐照贮存3年的小麦种子.结果显示适宜的激光可降低小麦陈种子浸出液的电导率;有效地提高小麦陈种子的发芽势、发芽率、芽长和芽鲜重;显著提高小麦幼苗的苗高和根长,表明激光辐照是提高小麦陈种子萌发力和幼苗生长力的有效方法.     

水杨酸对锌胁迫下小麦幼苗生长抑制的缓解效应

以小麦品种‘新麦18’为材料,采用室内水培实验研究了不同浓度水杨酸(SA)处理对300 mg.L-1锌胁迫下小麦种子萌发和幼苗生长的影响。结果表明:在Zn2+胁迫下,小麦种子的发芽势和发芽率、幼苗根长、芽长以及幼苗叶片的可溶性蛋白含量、根系活力显著降低,而脯氨酸和丙二醛(MDA)含量显著增加(P<0.05);外施SA显著提高了Zn2+胁迫下小麦种子的发芽势和发芽率,同时也使Zn2+胁迫7 d后的小麦幼苗的根长、芽长,幼苗叶片的脯氨酸和可溶性蛋白含量以及根系活力显著升高,膜脂过氧化产物MDA含量却显著降低(P<0.05)。由此可见,外施SA可通过提高小麦幼苗根长和芽长来增加幼苗根系活力,通过提高小麦幼苗可溶性蛋白含量、脯氨酸含量来维持细胞膜的稳定性,降低膜脂过氧化伤害程度,从而缓解了Zn2+胁迫对幼苗生长的抑制,并以14 mg.L-1外源水杨酸缓解效果最好。     

不同时间的UV-B辐射对拟南芥幼苗生长的影响

以哥伦比亚野生型拟南芥(Arabidopsis thaliana)为实验材料, 用辐射功率为16.67 μW·cm^-2但不同时间(0.5、1、1.5、2、2.5和3小时)的UV-B辐射对拟南芥幼苗进行处理, 观察叶片形态, 并测定其根长、叶绿素含量、可溶性蛋白含量、丙二醛(MDA)浓度、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性及叶绿素荧光参数。结果显示, 短时间UV-B辐射可促进拟南芥根的伸长, 叶绿素和可溶性蛋白含量升高; 长时间UV-B辐射则抑制拟南芥根的生长, 使叶绿素含量、可溶性蛋白含量、叶绿素荧光参数F_v/F_m及qP逐渐降低, MDA浓度、SOD活性、CAT活性和qN值升高, 并随着时间的延长逐渐降低或升高。当辐射功率为16.67 μW·cm^-2时, 其最佳辐射时间为1.5小时。UV-B辐射作为一种环境胁迫, 其胁迫程度都是在一定的范围内, 当胁迫达到极限时, 植株都会对UV-B辐射产生一定的适应效应而使损伤降低。     

黄腐酸浸种对PEG模拟干旱胁迫下紫花苜蓿种子萌发及幼苗生长的影响

以紫花苜蓿(Medicago sativa L.)为研究对象,采用不同PEG模拟干旱处理(CK、10%PEG、0.03%FA+10%PEG和0.05%FA+10%PEG)方法,探讨黄腐酸(FA)浸种对紫花苜蓿种子萌发、幼苗生长及抗逆性生理生化指标的影响。结果显示:(1)在PEG模拟干旱胁迫下,紫花苜蓿种子的发芽率、发芽势、发芽指数、活力指数、以及幼苗叶绿素含量、膜稳定指数(MSI)和根系活力较对照均呈下降趋势,株高和生物量的增长速率均显著低于对照;而幼苗叶片丙二醛(MDA)、过氧化氢(H2O2)、脯氨酸、可溶性糖含量均随处理时间呈上升趋势,过氧化氢酶(CAT)和谷胱甘肽还原酶(GR)活性则呈下降-升高-下降的趋势,超氧化物歧化酶(SOD)、过氧化物酶(POD)活性及超氧阴离子(O-·2)产生速率则均呈先升高后降低的趋势。(2)经黄腐酸浸种处理后,模拟干旱胁迫下紫花苜蓿种子的发芽率、发芽势、发芽指数、活力指数和幼苗株高、生物量、脯氨酸和可溶性糖含量均显著升高,并显著减小了模拟干旱胁迫引起的叶绿素含量、根系活力和MSI下降的幅度,相对提高了SOD、POD、CAT、GR活性,降低了MDA、H2O2含量和活性氧水平。研究表明,10%PEG模拟的干旱胁迫使紫花苜蓿的种子萌发及幼苗生长发育受到显著抑制,而黄腐酸浸种处理可通过提高渗透调节物质含量和保护酶活性来有效缓解干旱胁迫对紫花苜蓿幼苗造成的氧化伤害,增强植株的整体抗旱性,维持其正常生长发育,并以0.05%黄腐酸浸种对干旱胁迫下紫花苜蓿种子萌发及幼苗生长的保护效应较为显著。     

Flor-essence对小麦种子萌发和幼苗生长的影响

研究不同浓度Flor-essence对小麦种子萌发及幼苗生长的影响,以开拓其在植物生长调节剂领域的新应用。通过室内水培试验,分别设定50、100、150、200和250 mg/L 5组不同浓度的Flor-essence溶液处理,测定小麦种子发芽和植株生长的相关指标,同时选取清水(0 mg/L Flor-essence)和0.015 mg/L的油菜素内酯(BR)作对照。结果显示,与对照相比,不同浓度Floressence浸种均促进了小麦种子的萌发和生长,小麦的发芽势、发芽率、发芽指数、根长、株高、鲜重、干重、叶绿素含量和根冠比均有不同程度提高。不同浓度处理中,以200和250 mg/L处理的幼苗发芽情况最好;以150 mg/L处理的株高最高;以200 mg/L处理的根长最长、根冠比最大;以250 mg/L处理的鲜重、干重和叶绿素含量最高。利用Flor-essence浸种可促进小麦种子萌发和幼苗生长,且浓度为150-250 mg/L Flor-essence更能够在不同程度上促进小麦苗期的生长。     

活性炭对烟农19小麦发芽及其幼苗生长的影响

以烟农19号小麦种子为实验材料,采用园土为基本培养材料,用0.0（CK）、0.5、1.0、1.5、2.0 g活性炭与150 g园土混合均匀后装入培养容器中培养。发芽后测定小麦发芽率、株高、根长、鲜重等性状指标及还原性糖和叶绿素含量。结果表明：在实验范围内,随着活性炭施用比例的增加,小麦根长、还原性糖含量以及叶绿素含量呈先增后降的趋势,株高和发芽率持续增加。因此认为,适量施用活性炭能有效促进小麦的生长发育。     

Accumulated effect of elevated ultraviolet-B radiation over multiple generations of the arid-environment annual Dimorphotheca sinuata DC. (Asteraceae)

Two D. sinuata populations, established from the same seed batch, were cultured concurrently under ambient (2.5–8.9 kj m^?2 d^?1) and enhanced (4.7–11.4 kj m^?2 d^?1) ultraviolet-B radiation for two consecutive generations. The two populations, designated low- and high-UV-B cultivars, were each grown for an additional generation under both UV-B fluences at different alignments. Differences in plant performance were examined between UV-B treatments (immediate UV-B effects), cultivars (accumulated UV-B effects), alignments and their interactions. Accumulated UV-B had a greater effect on plant performance than immediate UV-B. The former induced earlier reproductive effort, substantial (up to 35%) reductions in dry mass (stems, leaves and reproductive organs), decreased stem and inflorescence production, and diminished steady-state fluorescence yields, chlorophyll a concentrations, pollen tube growth and germination of seeds set. The latter caused only diminished non-photochemical quenching, reduced chlorophyll a, soluble sugar and starch concentrations, decreased pollen germination, and increased carotenoid contents. Interactions between UV-B fluence level and alignment occurred for all measured dry mass parameters, leaf area, photosynthetic pigment and soluble sugar concentrations, and germination success of seeds set. These results indicate altered DNA integrity rather than an indirect UV-B effect of photomorphogenic origin.     

罗布麻对不同浓度盐胁迫的生理响应

利用网室盆栽实验, 研究不同浓度的NaCl(100–400 mmol·L^–1)胁迫对罗布麻(Apocynum venetum)生长及生理特性 的影响。结果表明, 100 mmol·L^–1NaCl处理显著降低了罗布麻植株的鲜重, 但对其干重影响不大; 随着盐浓度继续增加, 罗布麻鲜重和干重显著下降。在盐胁迫下, 罗布麻叶片内的丙二醛含量、电解质渗漏率、根部和地上部Na⁺的含量明显增加, K⁺的含量随着盐离子浓度的增加而降低。盐胁迫显著降低了地上部Ca²⁺的含量, 而对根部Ca²⁺的含量没有影响。植株K⁺/Na⁺和Ca²⁺/Na⁺比值随着盐胁迫强度的增加而降低。盐胁迫显著促进了罗布麻根部对K⁺和Ca²⁺的选择性吸收及对K⁺的选择性运输。当NaCl浓度小于或等于200 mmol·L^–1时, 随着盐离子浓度的增加, 罗布麻叶片内的脯氨酸和可溶性糖积累显著增加,而当NaCl浓度大于200 mmol·L^–1时, 这2种有机溶质含量显著下降。总体上, 罗布麻通过积累无机离子、合成有机溶质及维持较高的K⁺、Ca²⁺选择性吸收和运输来适应一定浓度(≤200 mmol·L^–1NaCl)的盐胁迫。     

Effect of seed pretreatment by magnetic field on the sensitivity of cucumber (Cucumis sativus) seedlings to ultraviolet-B radiation

The effects of seed pretreatment by magnetic field (MF) on the impacts of ultraviolet-B (UV-B) radiation were tested using cucumber (Cucumis sativus) seedlings in phytotron. Soaked cucumber seeds were placed in MF of various strengths (0, 0.2 and 0.45 T). After germination the seeds were sowed in homogeneous garden soil and grown, then cucumber seedlings were exposed to 0 (as control) and 3.5 kJ m⁻² UV-B irradiation, respectively. Some effects of UV-B radiation and MF-pretreatment as well as their combination were investigated. MF-pretreatment increased seed germination rate, seedling growth and development, although also increased lipid oxidation and ascorbic acid contents. On the other hand, our results provided evidence that seed MF-pretreatment increased the sensitivity of cucumber seedlings to UV-B radiation. The seedling growth and development were significantly decreased by the combination of UV-B irradiation and MF-pretreatment. This combination also increased oxidative pressure and decreased actual quantum yield of PS II. Leaf UV-B absorbing compound was increased by MF-pretreatment or UV-B irradiation, whereas their combination significantly decreased it. These results suggested that the harmful effects of combination were partially due to the inhibition of secondary metabolism.     

Effect of salinity on seed germination,seedling growth,and physiological characteristics of Perilla frutescens

Abstract

Salt stress is one of the major environmental factors limiting crop growth and yield. To understand the effect of salt stress on plant growth, we investigated the response of three perilla varieties (Suyin 1, Ziye 7, and Ziye 10) to NaC1 exposure at concentrations of 0, 50, 100, 150, 200, and 250 mM in terms of seed germination, seedling growth, root activity, contents of soluble sugar, proline, and malondialdehyde (MDA), and peroxidase (POD) enzyme activity. Germination characteristics, such as the percentage of seed germination, tended to decrease with increasing NaC1 concentrations. After three weeks of salt stress, the three varieties exhibited different salt tolerance in terms of seed germination, seedling growth, and physiological changes: seedling growth was inhibited to various degrees, seedling vigor and root activities decreased, and MDA, proline, and soluble sugar contents increased with increasing NaCl concentrations. POD enzyme activity, a protective mechanism against salt stress, increased at low NaC1 concentrations in Suyin1 (0–150 mM) and Ziye 7 (0–100 mM), and then decreased at higher NaCl concentrations. In Ziye 10, on the other hand, POD activity dropped significantly with increasing NaCl concentrations. These results suggest that among the three varieties Suyin 1 is more salt tolerant than Ziye 7 and Ziye 10, and that Ziye 10 is the most sensitive to salt stress.     

不同温度对迷人杜鹃种子萌发与幼苗生长及生理特性的影响

该研究利用实验室不同恒温和变温控制试验,考察了不同温度[恒温(15℃、25℃、35℃)和变温(25℃/15℃、30℃/20℃,高温12 h,低温12 h)]处理对迷人杜鹃种子萌发、幼苗形态指标和生理生化指标的影响,探讨温度对迷人杜鹃种子萌发和幼苗生长的影响机制。结果表明:(1)迷人杜鹃种子在25℃/15℃变温条件下萌发率(87.69%)和萌发指数(8.65)均最高。(2)25℃/15℃变温有利于迷人杜鹃幼苗的地径、苗高、平均根长和萌枝数的增加,以及根、茎、叶生物量的积累。(3)25℃/15℃变温处理下幼苗叶片的总叶绿素、可溶性糖和可溶性蛋白含量最高,而MDA含量、CAT活性和SOD活性较低。研究认为,迷人杜鹃种子萌发和幼苗生长的最适宜温度条件为25℃/15℃(昼/夜),而在高温(35℃)和低温(15℃)环境下均会受到显著抑制。     

小珊瑚藻对赤潮异弯藻的克生效应及其 对UV-B辐射增强的响应

通过共培养方法,以细胞密度为主要测定指标,研究了小珊瑚藻对赤潮异弯藻的克生效应及其对UV-B辐射增强的响应.结果表明：小珊瑚藻的新鲜组织和水溶性抽提液对赤潮异弯藻的生长表现出显著的抑制作用(P＜0.05),说明小珊瑚藻对赤潮异弯藻具有克生效应;而小珊瑚藻干粉末和培养水过滤液对赤潮异弯藻生长则无明显影响(P>0.05).将小珊瑚藻用不同剂量的UV-B辐射预处理后,再与赤潮异弯藻共培养,除培养水过滤液外,其新鲜组织、干粉末和水溶性抽提液对赤潮异弯藻生长的作用效果均有所改变,高剂量(3.0 J·m^-2)UV-B辐射使小珊瑚藻对赤潮异弯藻的抑制作用减弱(P＜0.05),而低剂量(0.9 J·m^-2) UV-B辐射则使抑制作用增强(P＜0.05).