镉胁迫下4种宿根花卉的生理生长响应及其抗性差异

以百合科宿根花卉大花萱草、“金娃娃”萱草、“甜心”玉簪、东北玉簪为研究材料,研究其在Cd质量浓度为40 mg/kg处理下,随着植物体内镉的积累,不同时期4种花卉生理生长的响应,并根据各项指标的测定结果对4种花卉的抗镉胁迫能力进行综合评定。结果表明,镉胁迫下,植株受害情况不仅受时间主效应的影响,还受时间×树种、时间×树种×质量浓度交互效应的影响。经方差分析和多重对比,并用隶属函数法进行综合评定,[JP3]得出4种花卉的抗镉胁迫能力强弱顺序依次为“甜心”玉簪、“金娃娃”萱草、大花萱草和东北玉簪。[JP]     

杂交鹅掌楸不同无性系对Pb胁迫的生理响应及抗性比较

采用盆栽法研究了4个杂交鹅掌楸(Liriodendron chinense×L.tulipifera)无性系扦插苗对土壤Pb胁迫的生理响应与抗性差异。研究结果表明,Pb胁迫能抑制杂交鹅掌楸无性系扦插苗生长,使叶片失绿变黄、根系活力下降,且1.0mg·g-1Pb胁迫的抑制效果更明显。随Pb胁迫时间的延长,4个杂交鹅掌楸无性系扦插苗叶片的相对电导率和MDA含量均持续增加,胁迫结束时,相对电导率和MDA含量分别是对照的1.45~1.92倍和2.23~3.23倍。叶片的POD活性和游离脯氨酸含量在整个Pb胁迫过程中呈先升后降的变化趋势;不同无性系的SOD活性变化存在一定差异。随着Pb浓度的增加,杂交鹅掌楸不同无性系扦插苗各生理指标的变化幅度各异。比较发现,无性系NE60对Pb胁迫的抗性最强。     

Pb胁迫对路易斯安那鸢尾幼苗生长和生理生化特性的影响

采用液体培养法研究了0（CK）、200、400、600和800 mg·L-1Pb胁迫条件下路易斯安那鸢尾（Louisiana Iris）品种‘Professor Neil’幼苗生长,叶片叶绿素含量,叶片和根系的丙二醛（MDA）和脯氨酸（Pro）含量、超氧阴离子自由基（O-·2）产生速率以及超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性的变化。结果表明：随Pb质量浓度的提高,幼苗的株高、根长、叶片和根系干质量以及耐性指数总体呈逐渐下降的趋势,且总体上显著低于对照（P〈0.05）,但各处理组间差异不显著。幼苗叶片的叶绿素a和b含量均随Pb质量浓度提高而缓慢下降,但仅在800 mg·L-1Pb胁迫条件下叶绿素a含量显著低于对照（P〈0.05）,其余处理组的叶绿素a和b含量及叶绿素a/b比值均与对照无显著差异。叶片和根系的MDA和Pro含量及POD活性均随Pb质量浓度提高逐渐增加,根系的SOD活性则随Pb质量浓度提高逐渐降低;而叶片的SOD活性以及叶片和根系的CAT活性和O-·2产生速率均在200~600 mg·L-1Pb胁迫条件下随Pb质量浓度提高逐渐增加,但在800 mg·L-1Pb胁迫下均不同程度降低,表明路易斯安那鸢尾可通过体内抗氧化酶和相关物质的诱导及合成缓解低浓度Pb胁迫对其造成的毒害作用,而高浓度Pb胁迫对路易斯安那鸢尾的伤害较重。综合分析结果表明：路易斯安那鸢尾具有一定的耐Pb特性和修复Pb污染水体的潜能。     

不同砧木黄瓜嫁接苗对温度胁迫的生理响应及其抗性评价

以4种砧木和‘春秋王2号’( Cucumis sativus ‘Chunqiuwang No.2’)黄瓜为嫁接试材,在人工气候箱内对嫁接苗和自根苗进行了连续3 d的低温(昼12 ℃/夜5 ℃)、高温(昼42 ℃/夜35 ℃)和常温(昼25 ℃/夜18 ℃)3组处理,分析温度胁迫对嫁接苗和自根苗的伤害指数、光合特性和抗氧化系统的影响,明确不同砧木嫁接苗对低温和高温抗性机制的异同,为黄瓜设施栽培生产中不同季节选择嫁接砧木提供依据。结果表明:(1)低温胁迫下,黑籽南瓜( Cucurbita ficifolia Bouché)砧嫁接苗冷害指数最低,其次为日本南瓜( Cucurbita moschata )砧嫁接苗,两者的相对叶绿素含量、净光合速率( P n)、超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和可溶性蛋白含量比常温对照增加较多,且两者丙二醛(MDA)含量较低。(2)高温胁迫下,‘五叶香’丝瓜( Luffa cylindrica ‘Wuyexiang’)砧嫁接苗热害指数最低,同时叶绿素含量、抗坏血酸过氧化物酶(APX)活性和可溶性蛋白含量均相对较高,MDA含量最低;‘甬砧8号’( Cucurbita maxima×Cucurbita moschata ‘Yongzhen No.8’)白籽南瓜砧和日本南瓜砧嫁接苗热害指数也较低,且SOD、CAT和APX活性较高。(3)不同嫁接组合的抗性综合评价结果显示,黑籽南瓜砧嫁接苗的耐寒性最强,丝瓜砧嫁接苗的耐热性最强,日本南瓜砧嫁接苗和‘甬砧8号’砧嫁接苗对高温和低温均具有一定的耐受性。研究发现,黑籽南瓜砧等嫁接组合可以通过维持光合性能,提高抗氧化酶活性,增加渗透调节物质含量来缓解高低温度胁迫造成的过氧化伤害,从而表现出对高低温胁迫的较强抵抗力。     

Pb-Cu复合胁迫对马蔺幼苗生长和生理指标的影响

采用营养液培养法,研究了不同质量浓度Pb-Cu复合胁迫对马蔺[Iris lactea Pall. var. chinensis (Fisch.)Koidz.]幼苗生长和一些生理指标的影响. 结果表明, 处理35 d后, 在50.00 mg·L-1Pb与0.10、 1.00、 10.00 mg·L-1Cu组成的3个复合胁迫处理组中,马蔺幼苗的株高、根长、地上部分和地下部分的鲜质量和干质量、叶片叶绿素a(Chla)和叶绿素b(Chlb)的含量均低于对照组(0.00 mg·L-1Pb-0.01 mg·L-1Cu),叶片SOD和POD活性则显著高于对照组;其中,50.00 mg·L-1Pb-10.00 mg·L-1Cu处理组幼苗的株高、根长、Chla和Chlb含量及SOD和POD活性均最高,地上部分和地下部分的鲜质量和干质量也较高.在100.00 mg·L-1Pb与0.10、1.00、10.00 mg·L-1Cu组成的3个复合胁迫处理组中,100.00 mg·L-1Pb-0.10 mg·L-1Cu处理组幼苗的株高、根长、地上部分和地下部分的鲜质量及干质量、Chla和Chlb含量以及SOD和POD活性基本上都显著高于对照组,100.00 mg·L-1Pb-1.00 mg·L-1Cu处理组中幼苗的株高、地上部分鲜质量和干质量以及叶片的SOD和POD活性也均显著高于对照组;而在100.00 mg·L-1Pb-10.00 mg·L-1Cu处理组中幼苗的株高、根长以及地上部分和地下部分的鲜质量和干质量均最低,Chla和Chlb的含量则显著低于对照组.研究结果表明, 50.00 mg·L-1Pb与较高质量浓度Cu(10.00 mg·L-1)复合处理可在一定程度上缓解Pb胁迫对马蔺幼苗的伤害;而100.00 mg·L-1Pb与较低质量浓度Cu(0.10 mg·L-1)复合处理不但能减轻Pb胁迫对马蔺幼苗的伤害,还有一定的刺激生长的作用;但较高质量浓度的Pb-Cu复合胁迫则加剧了对马蔺幼苗的生长和生理代谢的抑制作用.     

Pb胁迫条件下狭叶香蒲种子的萌发特性及其幼苗的生理响应

对0、30、150、300、450和600μmol·L-1Pb胁迫条件下狭叶香蒲（TyphaangustifoliaLinn.）种子的萌发特性进行了研究,并分析了0、450、900、1800和2700μmol·L-1Pb胁迫对狭叶香蒲幼苗叶片及根系中部分生理生化指标的影响。结果表明：随Pb浓度提高,狭叶香蒲种子的发芽率、发芽势、发芽指数和活力指数以及下胚轴长度均逐渐下降且低于对照,而其下胚轴长度抑制指数则逐渐增大,但在30μmol·L-1Pb胁迫条件下各项萌发指标均与对照无显著差异。叶片叶绿素a、叶绿素b及总叶绿素含量随Pb浓度提高呈逐渐下降趋势,但在450和900μmol·L-1Pb胁迫条件下与对照无显著差异,而在1800和2700μmol·L-1Pb胁迫条件下显著低于对照。在Pb胁迫条件下叶片和根中SOD活性均显著高于对照但变化趋势不同;随Pb浓度提高,叶片SOD活性呈波动但整体上升的趋势,而根中SOD活性则呈逐渐降低的趋势。叶片和根中POD活性均随Pb浓度提高呈持续上升的趋势,其中,在450和900μmol·L-1Pb胁迫条件下叶片的POD活性低于对照、根的POD活性高于对照,但均与对照无显著差异;而在1800和2700μmol·L-1Pb胁迫条件下叶片和根的POD活性均显著高于对照。在Pb胁迫条件下叶片和根中AsA和MDA含量均高于对照。随Pb浓度提高,叶片的AsA含量总体上逐渐增加但在450和900μmol·L-1Pb胁迫条件下与对照无显著差异;而根的AsA含量则呈先增加后降低的趋势且均与对照差异显著。随Pb浓度提高,叶片的MDA含量先增后降但均与对照无显著差异;而根的MDA含量呈“高-低-高”的波动趋势且仅在450μmol·L-1Pb胁迫条件下与对照差异显著。综合分析结果显示：狭叶香蒲幼苗根系对Pb胁迫的敏感性可能强于叶片;狭叶香蒲种子可在轻度Pb污染水体中萌发和生长;其幼苗对Pb胁迫具有一定的耐性,可用于中度Pb污染水体的修复。     

多花黑麦草对铝胁迫的生长生理响应

以多花黑麦草(Lolium multiflorum Lam.)为材料,采用盆栽实验法,对其进行不同浓度铝(Al)的胁迫处理(0、100、200、300、400、500 mg/kg),并测定植株胁迫后的各项生长和生理指标。结果显示,Al胁迫会抑制多花黑麦草的生长和生物量的积累,Al~(3+)含量越高,其抑制作用越强。其中,土壤Al~(3+)含量为500 mg/kg时对植物株高和地上部的干重产生显著抑制作用;而当Al~(3+)含量为100 mg/kg时对植物根长和根干重产生显著抑制作用。叶绿素a、叶绿素b和叶绿素总量均随Al~(3+)含量的升高而降低,其中Al~(3+)含量为500 mg/kg时,叶绿素a、叶绿素b分别比对照下降了56.81%和46.57%。地上部和根系中的可溶性糖、游离脯氨酸、MDA含量和SOD活性均随Al~(3+)含量的升高而升高,且上述地上部4个指标均高于根系。     

高温胁迫下五种杜鹃花属植物的生理变化及其耐热性比较

高温是制约分布于较高海拔地区杜鹃花迁地保育与园林应用的重要因子.为探讨杜鹃花属植物的 高温致伤机理,该实验以隶属不同亚属的白花杜鹃、羊踯躅、毛棉杜鹃、红滩杜鹃及红棕杜鹃4年生实生苗为 材料,通过人工气候箱的盆栽实验,研究了30℃、38℃高温胁迫下其叶片生理生化指标的变化,并利用隶属 函数法及系统聚类分析法对其种间...     

3个山茶品种对干旱胁迫的生理响应

以山茶(Camellia japonica)品种‘红露珍’、‘六角大红’和‘烈香’两年生扦插盆栽苗为试材,进行干旱胁迫试验,测定3个山茶品种在干旱胁迫下叶片相对含水量、叶绿素含量、丙二醛(MDA)含量等7种生理生化指标,分析不同山茶品种的生理响应,通过隶属函数法综合评定不同山茶品种的抗旱性。结果表明,3个山茶品种抗旱能力由强到弱依次为‘六角大红’>‘红露珍’>‘烈香’。     

水分胁迫下嫁接对茄子生长及其生理生化指标的影响

以野生茄托鲁巴姆(Solanum torvum)为砧木,茄子品种西安绿茄为接穗进行嫁接,研究不同水分胁迫下嫁接对其生长和生理生化指标的影响.结果表明:土壤水分胁迫严重限制了嫁接茄和自根茄的生长,在对照(80％ ～85％)处理下差异不明显,在轻度(50％ ～55％)、重度(35％～40％)水分胁迫下差异显著;与自根茄相比,各处理嫁接茄的株高和茎粗显著增加(P＜0.05);地上部鲜重、根鲜重和地上部干重、根干重均呈显著增加趋势;叶片相对含水量和叶绿素含量也显著增加;而相对电导率和丙二醛( MDA)含量较自根茄显著下降;嫁接极显著地增加了叶片的脯氨酸和可溶性糖含量;随着胁迫时间的延长和程度的加大,嫁接茄叶片的超氧化物酶(SOD)和过氧化物酶(POD)活性与自根茄差异达显著水平(P＜0.05);嫁接增强了植株长势,能够调节自身渗透调节物质的含量和保护酶系统活性,来减轻干旱伤害,维持植物体的正常生理代谢功能,表现出较强的抗旱耐旱能力.     

木榄幼苗对淹水胁迫的生长和生理反应

在搭建于广西英罗湾红树林外裸滩的试验平台上设置8个海面高程组,研究全日潮海区潮汐淹水胁迫对木榄(Bruguiera gymnorrhiza)幼苗的生长和生理影响.幼苗立地基质平面的海面高程为320～390 cm,相邻高程组相差10 cm,幼苗培养时间为1 a.结果表明:小高程和大高程处理均促进木榄幼苗茎高度的增长,中等高程则起抑制作用;中等高程组幼苗茎节数稍少;叶数、叶面积与叶保存率均随淹水程度加大而急剧下降;小高程生境对叶片叶绿素含量的促进作用较微弱,而大高程生境更有利于叶绿素含量上升;但较长时间的淹水胁迫使叶绿素a/b比值反而较高;小高程处理均促使叶片和根系中超氧物歧化酶(SOD)和过氧化物酶(POD)酶活性增强,同一高程组的木榄幼苗根系中超氧物歧化酶和过氧化物酶酶活性均高于叶片的数倍;较大高程生境更有利于木榄幼苗生物量累积,尤其是叶生物量,同时随着淹水程度的加大,新生器官中生物量分配比例由叶向茎转移;所有高程组均有一些幼苗死亡,海面高程越小幼苗存活率越低,由73.6%下降到35.0%.综合考虑,建议北部湾海区木榄胚轴造林的宜林临界线高程不低于当地平均海面以上21 cm.     

Osmotic stress affects physiological responses and growth characteristics of three pistachio cultivars

Pistachio (Pistacia vera L.) has a high tolerance to drought and soil salinity. Although adult pistachio trees are well known to be drought tolerant, the studies on physiological adaptation of pistachio cultivars to drought are limited. Therefore, three pistachio cultivars, i.e., Akbari, Kaleghochi, and Ohadi were subjected to three osmotic drought stress treatments: control (?0.1 MPa), moderate (?0.75 MPa) and severe drought (?1.5 MPa) stress using PEG 6000 for a 14-day period. All drought stress treatments decreased net photosynthesis (P _n), stomatal conductance (g _s), intercellular CO₂ concentration (C _i), and transpiration rate (E), but Ohadi maintained better its photosynthetic capacity compared to Akbari and Kaleghochi. Maximum quantum yield of PSII photochemistry (F _v /F _m), effective PSII quantum yield (ΦPSII) and photochemical quenching (qP) were also reduced. The chlorophyll fluorescence parameters indicated that Akbari was more susceptible to the applied drought stress. Drought stress levels decreased chlorophyll pigments, fresh weight, stem elongation, leaf nitrogen content (N), leaf water potential and increased water use efficiency (WUE). Proline increased strongly under drought stress for Akbari. After 2 weeks of stress a recovery of 2 weeks was applied. This period was insufficient to fully restore the negative effects of the applied stress on the studied cultivars. Based on the reduction of photosynthesis and the increase of the proline content Akbari seems more sensitive to the applied drought stress.     

Evaluation of physiological responses during recovery following three resistance exercise programs

The present study was conducted to examine (a) whether there is an association between maximal oxygen uptake (Vo(2)max) and reduction in postexercise heart rate (HR) and blood lactate concentrations ([La]) following resistance exercise and (b) how intensity and Volume of resistance exercise affect postexercise Vo(2). Eleven regularly weight-trained males (20.8 +/- 1.3 years; 96.2 +/- 14.4 kg, 182.4 +/- 7.3 cm) underwent 4 sets of squat exercise on 3 separate occasions that differed in both exercise intensity and volume. During each testing session, subjects performed either 15 repetitions.set(-1) at 60% of 1 repetition maximum (1RM) (L), 10 repetitions.set(-1) at 75% of 1RM (M), or 4 repetitions.set(-1) at 90% of 1RM (H). During each exercise, Vo(2) and HR were measured before (PRE), immediately post (IP), and at 10 (10P), 20 (20P) 30 (30P), and 40 (40P) minutes postexercise. The [La] was measured at PRE, IP, 20P, and 40P. Decrease in HR (DeltaHR) was determined by subtracting HR at 10P from that at IP, whereas decrease in [La] (Delta[La]) was computed by subtracting [La] at 20P from that at IP. A significant correlation (p < 0.05) was found between Vo(2)max and DeltaHR in all exercise conditions. A significant correlation (p < 0.05) was also found between Vo(2)max and Delta[La] in L and M but not in H. The Vo(2) was higher (p < 0.05) during M than H at IP and 10P, while no difference was seen between L and M and between L and H. These results indicate that those with greater aerobic capacity tend to have a greater reduction in HR and [La] during recovery from resistance exercise. In addition, an exercise routine performed at low to moderate intensity coupled with a moderate to high exercise volume is most effective in maximizing caloric expenditure following resistance exercise.     

Growth and physiological alterations in Niger cultivars under drought stress

Aim of the present study was to determine differential responses in growth and physiology of tolerant (cv. IGPN 2004) and sensitive (cv. GA 10) cultivars of Niger (Guizotia abyssinica Cass.) using in vitro grown calli under water deficit conditions. The calli were subjected to drought stress using PEG-8000 (–0.16,–0.45,–0.87,–1.42 bar) for 15 d and relative growth rate (RGR), percent tissue water content (% TWC), osmolytes (proline–Pro, glycine betaine—GB, total soluble sugars—TSS) accumulation, malondialehyde (MDA) content as well as antioxidant enzyme activities such as superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalase (CAT) were analysed. Our findings showed that RGR and percent TWC was decreased significantly with the intensity of drought stress in both cultivars, but the RGR reduction was least (five folds) in cv. IGPN 2004 than in cv. GA 10 (6.2 folds). In osmolyte accumulation such as Pro and GB, cv. IGPN 2004 was found superior (5.5 and ten folds higher, respectively) to tolerate drought stress than GA 10; however, no change was observed in TSS accumulation. Further, it was noted that cv. IGPN 2004 caused least oxidative damage to the membranes. It also exhibited better SOD, CAT and APX activities and had higher α-tocopherol content. The least reduction in growth and MDA content and higher osmolytes and antioxidant activities in cv. IGPN 2004 revealed more drought stress tolerance at cellular level. It was suggested that increased drought tolerance of cv. IGPN 2004 was coupled with its better maintenance of RGR, percent TWC, reduced lipid peroxidation, more accumulation of osmolytes and higher antioxidant enzymes.     

Soil microbial communities buffer physiological responses to drought stress in three hardwood species

Trees possess myriad adaptations for coping with drought stress, but the extent to which their drought responses are influenced by interactions with soil microbes is poorly understood. To explore the role of microbes in mediating tree responses to drought stress, we exposed saplings of three species (Acer saccharum, Liriodendron tulipifera, and Quercus alba) to a four week experimental drought in mesocosms. Half of the pots were inoculated with a live soil slurry (i.e., a microbial inoculum derived from soils beneath the canopies of mature A. saccharum, L. tulipifera or Q. alba stands), while the other half of the pots received a sterile soil slurry. Soil microbes ameliorated drought stress in L. tulipifera by minimizing reductions in leaf water potential and by reducing photosynthetic declines. In A. saccharum, soil microbes reduced drought stress by lessening declines in leaf water potential, though these changes did not buffer the trees from declining photosynthetic rates. In Q. alba, soil microbes had no effects on leaf physiological parameters during drought stress. In all species, microbes had no significant effects on dynamic C allocation during drought stress, suggesting that microbial effects on plant physiology were unrelated to source–sink dynamics. Collectively, our results suggest that soil microbes have the potential to alter key parameters that are used to diagnose drought sensitivity (i.e., isohydry or anisohydry). To the extent that our results reflect dynamics occurring in forests, a revised perspective on plant hydraulic strategies that considers root-microbe interactions may lead to improved predictions of forest vulnerability to drought.     

镉胁迫下金银花的生长反应及积累特性

采用水培试验方法,研究了藤本植物金银花在不同浓度镉（Cd）胁迫下的生长反应和积累特 性,结果表明,Cd对金银花生长未造成显著影响,甚至低浓度(5和10 mg·L^-1) Cd具有一定的生长促进作用,表现为植物的株高和叶绿素含量有所增加。当Cd处理浓度达到50 mg·L^-1时,植物的株高和根长虽有所降低,但与对照相比并无显著差异,且耐性系数均＞0.8,表明金银花对Cd具有较强的耐性。当Cd处理浓度为25 mg·L^-1时,金银花地上部中Cd含量达到286.12 μg·g^-1,而富集系数均＞1,说明金银花具备Cd超富集植物的特征,对Cd污染土壤的修复具有很大的应用潜力。