盐胁迫对柳树无性系SH31离子含量及光合作用的影响

以柳树无性系SH31为试材,研究了NaCl溶液半抑制浓度胁迫下根、茎、叶中Na⁺、K⁺、Ca²⁺ 的分布规律及叶片光合特性的变化。结果表明:在NaCl溶液半抑制浓度(0.6%)下,SH31耐盐性较强;在0.6% NaCl溶液胁迫下,根部在前16 d积累大量Na⁺并拦截部分Na⁺向地上部运输;盐胁迫降低了根、茎部对 K⁺ 的吸收,而叶部却保持较高的K⁺ 含量来维持离子平衡;Ca²⁺含量在根、茎、叶中与对照的相当。在NaCl溶液半抑制浓度盐胁迫下,SH31 的净光合速率前7 d降低之后保持稳定,而气孔导度、蒸腾速率、胞间CO₂先降后升,表明前7 d的蒸腾速率下降的主要原因在于气孔限制。SH31根部对Na⁺ 选择性吸收并维持K⁺、Ca²⁺的高含量及维持较高光合作用是其重要的耐盐机制。     

淹水对13种乔木柳插条表型和生理指标的影响

为筛选优良的耐淹林木品种以满足我国湿地生态发展的需求,选取了13种乔木柳1年生插条实行淹水胁迫试验,通过测定根叶长、干鲜重等表型指标,丙二醛含量、叶绿素含量生理指标并对测定的数据进行分析,以对乔木柳品种耐淹性进行分型。结果表明,淹水对13种乔木柳根、叶的生长均有抑制作用,其中丙二醛含量在J1010中相对于对照组增加了4倍,在苏柳172中为2.4倍,叶绿素含量均出现明显降低,J2087仅为对照组的16.1%,竹柳为对照组的50%。另外总根长、总生根数、最长根长、叶片数、总萌枝长、叶鲜重、叶干重、根鲜重和根干重之间呈极显著正相关（P<0.01）,而总萌枝数与其他指标之间没有相关性。通过对表型指标和生理指标进行聚类分析、主成分分析和耐淹系数计算,可将13种乔木柳分成3类:竹柳、苏柳795、龙爪柳、苏柳172为强耐淹品种;渤海柳1号和苏柳932为中度耐淹品种;J2087、J2187、287、盐柳1号、东营1号、J1010和紫杆柳为弱耐淹品种。研究结论可为湿地耐淹林木的筛选提供依据,为柳树耐淹评价体系建立和耐淹机理研究奠定基础。     

Role of free neuromasts in larval feeding of willow shiner Gnathopogon elongatus caerulescens Teleostei, Cyprinidae

ABSTRACT:   It has been reported that the larvae of willow shiner Gnathopogon elongatus caerulescens have many free neuromasts on their body surface. This study examined the ability of the willow shiner larvae to feed on zooplankton by mechanoreception by the free neuromasts. Feeding experiments using untreated larvae and larvae treated with streptomycin, which impairs free neuromast function, were conducted under light and completely dark conditions. The larvae were put into Petri dishes, then nauplii of Artemia salina were introduced. The average number of Artemia eaten by the larvae was expressed as the average ingestion rate of Artemia /10 min. The ingestion rate of Artemia for untreated larvae was 12.3 under light conditions and 10.6 Artemia /10 min. even in complete darkness. The ingestion rate in the larvae treated with streptomycin was 11 under light conditions and only 0.8 Artemia /10 min under dark conditions. The low rate in the treated larvae under dark conditions must be due to impairment by the streptomycin. Therefore, the high ingestion rate for the untreated larvae under dark conditions would be surely dependent on mechanoreception. The results indicate that larval willow shiner is able to feed on zooplankton under limited light conditions.     

盐胁迫对2个灌木柳无性系光响应特征的影响

以2个灌木柳无性系(盐敏感型JW9-6和耐盐型JW2372)为试验材料,在温室水培条件下研究不同质量浓度盐(0,3,6 g/L)处理3 d对其光响应特征的影响。结果表明:2个无性系的最大净光合速率、饱和光强、表观量子效率和气孔导度均随盐质量浓度的升高而逐渐降低;根据气孔导度随光照度变化趋势的研究结果,认为6 g/L盐质量浓度处理引起JW2372和JW9-6光合速率下降的原因分别是气孔因素和非气孔因素;相同盐质量浓度处理条件下JW2372光响应特征参数受影响比JW9-6小,对光照强的利用能力更高。     

柳枝浸提液对小麦籽粒发芽的抑制作用研究

研究了柳树枝叶浸提液对小麦籽粒发芽的抑制效应，结果表明：抑制作用的大小随浸提时间和浸提液浓度的不同而异，煎煮时间对小麦种子发芽抑制强度依次为4h〉3h〉2h〉0．5h，浸提液不同浓度的抑制效果为280g／L〉200g／L〉120g／L〉40g／L。     

柳树叶组织蒸腾强度及离体叶片水分自然散失速度测定分析

对5个柳树树种的叶组织蒸腾强度、离体叶片水分散失速度、叶组织含水率、水分损失率进行了测定结果表明,苏柳在正常生长情况下较青刚柳和准噶尔柳节约水资源;由水分散失速度得出这5个树种在极端干旱条件下的抗性顺序为:J194柳>J172柳>J369柳>青刚柳>准噶尔柳;苏柳叶组织对其含水量变化反应敏感,出现水分胁迫后,组织含水率呈缓慢下降趋势,在组织含水率下降至50%时,仍具活叶特征,表明苏柳叶组织具有很强的生命力和抗干旱能力;J194柳的叶组织抗逆性最强,其次为J172柳和J369柳,青刚柳和准噶尔柳的叶组织抗逆性最弱。     

Heavy‐metal mobilization and uptake by mycorrhizal and nonmycorrhizal willows (Salix × dasyclados)

Ectomycorrhizal fungi have been shown to affect metal transfer from the soil to the host plant, but the use of these fungi for increased phytoextraction of heavy metals has been scarcely investigated. Therefore, a two‐factorial pot experiment was conducted with Salix × dasyclados and (1) two contaminated soils with different concentrations of NH₄NO₃‐extractable metals and (2) two strains of the ectomycorrhizal fungus Paxillus involutus (one strain originating from a noncontaminated site—Pax1, and another from a contaminated site—Pax2). The inoculation with Pax2 increased the phytoavailability of Cd in the soils. Inoculation with both fungal strains increased the stem and root biomass, but had no effect on metal concentrations in the stems. Decreased Cd and increased Cu concentrations were observed in the roots of inoculated willows. The inoculation with P. involutus increased Cd (up to 22%), Zn (up to 48%), and Cu content in the stems. Decreased Pb content (Cu and Pb content were always <1 mg per plant) occurred in the stems from plants at the soil with the higher concentration of NH₄NO₃‐extractable metals. Contrary to this, in the soil with lower concentrations of NH₄NO₃‐extractable metals, the inoculation had no significant effects on the total uptake of Zn and Cu and even caused decreased Cd (Pax2) and Pb (Pax1) contents in the stems. Strain Pax2 had higher colonization densities, but the plants had lower mycorrhizal dependencies in the contaminated soils than after inoculation with the strain Pax1. Generally, metal extractability in the soils substantially affected the mycorrhizal dependency and heavy‐metal uptake of the willows. We concluded, that the inoculation with P. involutus offers an opportunity to particularly increase the phytoextraction of Zn, but the metal extractability and fungal strain effects have to be tested.     

Revegetation of copper mine tailings with ryegrass and willow

To restore vegetation on metal mine tailings is very difficult because they often contain high concentrations of heavy metals, low nutrient content and low water retention capacity. This study involved 3 experiments that evaluated the effects of 4 treatment amendments: montmorillonite, rice straw, organic manure and chemical fertilizer on the growth of ryegrass (Loliurn perenne L.) and willow (Salix virninalis L.) with Cu and Zn mine tailings from two mining areas. The results showed that ryegrass was the most tolerant of 4 crops to Cu toxicity. Also when organic manure, which contained high concentrations of inorganic salts, was added to the mine tailings, it significantly hindered ryegrass growth (P=0.05).Meanwhile, with ryegrass organic manure significantly increased (P=0.05) the extractable Cu concentration in both mine tallings. When montmorillonite was used as a mine tailings amendment with willow, the height and tress number at the 1st cut were significantly greater (P = 0.05) than a control without montmorillonite. However there was no significant difference for height, tress number, dry weight or root dry weight at the 2nd cut. So, amendment applications to reduce metal toxicity and increase nutrients retention in mine tailings were essential during revegetation of mine tailings.     

干旱胁迫对2种速生树种叶绿素荧光特性的影响

【目的】对华南地区2个速生树种尾巨桉Eucalyptus urophylla×E.grandis和竹柳(bamboo willow)的抗旱性进行比较.【方法】采用干旱胁迫处理,利用脉冲调制式叶绿素荧光仪(OS5P-美国)对2树种叶绿素荧光参数进行测定.【结果和结论】在干旱胁迫条件下,实际光量子产量(Yield)、表观光合电子传递速率(ETR)、光化学淬灭系数(q P)、最大荧光(Fm)和PSⅡ最大光化学效率(Fv/Fm)均有不同程度的下降,在干旱处理第24天,尾巨桉ETR比对照下降48.02%,而竹柳仅下降25.12%;到重度干旱时期,尾巨桉和竹柳Fv/Fm分别下降31.55%和21.84%;供试树种的非光化学淬灭系数(q N)、初始荧光(F0)均呈上升趋势,与对照相比,竹柳q N上升幅度为217.59%,显著大于尾巨桉(146.40%,P0.05),F0上升幅度(49.11%)小于尾巨桉(92.03%);2种树种ETR与土壤含水量均呈极显著正相关(P0.01),尾巨桉F0与土壤含水量呈极显著负相关(P0.01),竹柳Fm和Fv/Fm与土壤含水量呈极显著正相关(P0.01).研究结果表明:在干旱胁迫下,竹柳与尾巨桉叶绿素荧光参数间均表现一定相关性,相比尾巨桉,竹柳在叶绿素荧光参数上表现出更强的抗旱性.     

Effect of Natural Feed,Antibiotics, Tannin,Diphenyliodoniumchloride and Salicylic Acid Supplement on Plasma Uric Acid Concentration in Captive Willow Ptarmigan (Lagopus L. Lagopus)

Mortality due to nephritis and uric acid diathesis was observed during the fall and winter in captive willow ptarmigan. The present study examined how feed protein concentration influences feed and water consumption, plasma uric acid concentration, and mortality due to nephritis and uric acid diathesis in captive w^rillow ptarmigan. An increase in feed protein concentration from 14 to 24 % resulted in reduced feed consumption and increased plasma uric acid concentration. Mortality due to nephritis and uric acid diathesis was not influenced by variations in feed protein concentration, but an admixture of 14 % grass meal to the diet reduced the incidence markedly.