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1.
该实验以筛选的速生、抗逆性强的5个柳树无性系(‘竹柳’、‘苏柳172’、‘苏柳795’、‘旱快柳’、‘旱柳’)一年生扦插幼苗为试验材料,设置对照、轻度(30mg·L-1)、中度(60mg·L-1)和重度(90mg·L-1)4个重金属Cd2+处理水平,通过水培方式探究Cd2+对各柳树无性系气体交换参数、荧光参数及叶绿素含量的影响。结果显示:(1)在Cd2+浓度为30mg·L-1时,导致‘苏柳172’、‘苏柳795’和‘旱快柳’净光合速率降低的原因主要是气孔因素;当Cd2+浓度≥60mg·L-1时,‘苏柳172’、‘苏柳795’、‘旱快柳’及‘竹柳’净光合速率下降的主要原因是非气孔因素,而‘旱柳’在整个Cd2+胁迫过程中净光合速率下降的因素均属于非气孔限制型。(2)整个Cd2+胁迫过程中,‘苏柳172’、‘苏柳795’、‘旱快柳’和‘旱柳’叶片叶绿素含量和Chl a/Chl b值与对照相比均呈下降趋势,而竹柳先上升后下降至低于对照水平。(3)随着Cd2+胁迫程度的增加,叶片PSⅡ最大光化学量子产量(Fv/Fm)和光化学淬灭(qP)整体呈下降趋势,非光化学淬灭系数(NPQ)呈逐渐上升的趋势,而表观光合电子传递速率(ETR)先增加后下降,但5个柳树无性系叶绿素荧光参数的变化幅度以‘竹柳’最小,‘旱柳’最大。研究表明,5个柳树无性系均能在Cd2+浓度为30mg·L-1的培养液中正常生长,且竹柳的光合作用较对照有略微增加,且在90mg·L-1 Cd2+浓度下各无性系生长虽受到抑制但仍能存活,说明它们对重金属Cd2+胁迫都有一定的耐受性,并以‘竹柳’的耐受性最强。  相似文献   

2.
耐性植物为环境污染植物修复提供了一条良好的途径。通过盆栽试验研究了垂柳(Salix babylonica Linn.)和苏柳172(Salix jiangsuensis J172)扦插苗对人工添加土壤铅污染的耐性及其对铅的积累和分配。结果发现:柳树生物量与土壤有效铅含量呈显著负相关关系,中低浓度的铅污染对两种柳树的根系生物量影响不大,Pb2+浓度为1600 mg·kg-1时显著降低垂柳根系生物量,苏柳172在Pb2+浓度为1 200和1 600 mg·kg-1时根系生物量极显著降低,说明垂柳对高浓度的Pb2+耐性要好于苏柳172;垂柳和苏柳172根系长度、根表面积、根体积和根直径随着土壤铅浓度的增加持续下降,在Pb2+浓度为1600 mg·kg-1时,垂柳根系长度、根表面积、根体积和根直径分别比对照下降了50.40%、45.15%、44.44%、9.10%,苏柳172分别下降了45.00%、45.88%、47.02%、37.14%。柳树吸收的铅绝大部分积累在根部,迁移到茎部和叶部的数量较少,铅在2种柳树体内不同部位的积累量均为根茎叶。当Pb2+浓度为800 mg·kg-1时,垂柳和苏柳172的耐性指数为91.15%和84.26%,其对土壤中铅的吸收量达140.20和149.49 mg,表明两种柳树对中等土壤铅污染的修复具有较大潜力。  相似文献   

3.
采用水培法,研究了Cu单一处理及Cu与EGTA和丹皮酚磺酸钠(SPS)复合处理对凤丹(Paeonia suffruticosa ‘Feng Dan’)幼苗根长、根系中Cu和丹皮酚含量的影响,并研究了Cu和SPS单一及复合处理对幼苗根系离体质膜和液泡膜微囊H+-ATPase活性的影响.结果显示:经5μmol·L-1Cu处理后凤丹幼苗根长和丹皮酚含量均略高于对照但总体上差异不显著;经10、20和30 μmol·L-1 Cu处理后,幼苗根长和丹皮酚含量总体上均低于对照,且随Cu浓度增加和处理时间延长,降幅增大.与10 μmol·L-1Cu单一处理相比,10 μmol·L-1Cu- 10μmol·L-1EGTA和10 μmo1.L-1Cu-10 μmol·L-1 SPS复合处理均可以使根系中Cu含量显著降低、丹皮酚含量显著提高;其中,10μmol·L-1Cu-10 μmol·L-1EGTA处理组幼苗根系中Cu含量的降低幅度最大,而10 μmol·L-1 Cu-10 μmol·L-1SPS处理组幼苗根系中丹皮酚含量的增加幅度最大且显著高于对照.与对照相比,经5、10和20μmol · L-1 Cu单一处理后丹凤根系离体质膜和液泡膜微囊H+-ATPase活性均降低,且随Cu浓度提高降低幅度增大;而经0.1、0.2、0.5和1.0μmol·L-1SPS单一处理总体上可使膜微囊H+-ATPase活性逐渐增加;与10 μmol·L-1Cu单一处理相比,10 μmol·L-1Cu与0.1、0.2和0.5 μmol·L-1SPS复合处理均可使膜微囊H+- ATPase活性提高,且H+-ATPase活性均呈现随SPS浓度提高逐渐增加的趋势.研究结果揭示:较高浓度Cu胁迫对凤丹幼苗根系生长及丹皮酚合成以及质膜和液泡膜微囊H+-ATPase活性均有明显抑制作用,但添加外源丹皮酚磺酸钠对Cu胁迫伤害具有一定的缓解效应.  相似文献   

4.
以5种一年生速生柳(竹柳、苏柳172、苏柳795、旱快柳、旱柳)幼苗为材料,通过盆栽铅胁迫实验,测定其生长过程中的生理生化指标,分析其对铅胁迫的生理响应及耐受性。结果表明:(1)随着Pb2+浓度的增加,5种速生柳叶片保护酶SOD、POD和CAT活性均呈先升高后降低的趋势,其中竹柳的3种保护酶活性均为最高。(2)随着Pb2+浓度的增加,各无性系叶片中渗透性调节物质可溶性蛋白、脯氨酸和可溶性糖含量均呈先上升后下降的趋势,竹柳和苏柳172在高Pb2+浓度(1500mg·kg-1)胁迫下表现出对Pb2+的强耐受性。(3)随着Pb2+浓度的增加,各速生柳无性系叶片丙二醛含量均呈逐渐增高的趋势,但增幅有所不同,竹柳增幅最小,旱柳增幅最大。(4)随着Pb2+浓度的增加,5种速生柳叶片中叶绿素含量均呈先上升后下降的趋势,但各无性系的下降幅度存在差异,其中竹柳的下降幅度最小,旱柳下降幅度最大。(5)随着Pb2+浓度的增加,5种速生柳根系活力都呈先上升后下降的趋势,其中竹柳的根系活力最强,苏柳795的最弱。(6)各速生柳根系对铅均有一定的吸附能力,竹柳对铅积累量最大。(7)对各生理指标的Fuzzy数学隶属函数综合评价结果表明,5种速生柳对Pb2+耐受性强弱表现为:竹柳旱快柳旱柳苏柳795苏柳172。  相似文献   

5.
本试验选用不同耐锌玉米品种,采用营养液水培,研究不同锌浓度对玉米株高、地上部干重、根干重及SOD、POD、TTC、硝酸还原酶活性、细胞膜透性的影响。结果表明:耐锌品种‘牡单九’的适宜锌浓度为0.1μmol.L-1,锌敏感品种‘四单十九’的适宜锌浓度为1μmol.L-1。不同锌浓度对玉米生长的影响主要表现在地上部,而对地下部生长影响较小。随着锌浓度的升高,SOD和POD的活性增大。当锌浓度为0.1μmol.L-1时根系活力最高,在锌浓度大于1μmol.L-1时,根系活力下降较明显。硝酸还原酶活性在锌浓度大于0.01μmol.L-1时,随着锌浓度升高而降低。在锌浓度为1μmol.L-1时,细胞膜透性最小,低锌和高锌胁迫下细胞膜透性都有不同程度的增加。  相似文献   

6.
本文研究了铜(Cu)胁迫下玉米(Zeamays)幼苗生长、叶绿素含量、叶绿素荧光参数和抗氧化酶活性的变化。研究结果表明,5 ̄20μmol.L-1Cu处理10天明显抑制玉米幼苗根系生长,并减少玉米幼苗的干物重,以及增加玉米幼苗地上部和根系含Cu量;玉米幼苗吸收的Cu大部分积累在根系,在地上部分布较少。Cu处理还降低玉米叶片的叶绿素含量和Fv/Fm、ETR、qP和qy值。在10天的Cu处理期间,根系中SOD、POD、CAT和GR活性呈现先上升后下降的趋势。而叶片中的SOD、POD、CAT和GR活性在处理前期不受Cu胁迫的显著影响,处理后期则因Cu胁迫而增强。实验表明抗氧化酶在抵御过量Cu引起的氧化胁迫中发挥了一定的作用。  相似文献   

7.
苏柳172和垂柳对Cu2+的吸收特性及有机酸影响   总被引:1,自引:0,他引:1       下载免费PDF全文
采用溶液培养的方法,研究了苏柳172和垂柳对Cu2+吸收的动力学特性及低分子量有机酸(乙酸和苹果酸)对Cu2+吸收的影响。结果表明:苏柳172和垂柳根系对Cu2+的吸收量随溶液Cu2+浓度的升高及吸收时间的延长而增加。苏柳172和垂柳对Cu2+吸收的浓度动力学曲线呈线性,非饱和曲线,可以用米氏方程很好地拟合。米氏方程拟合的结果说明,垂柳根系的Cu2+吸收能力要稍强于苏柳172。Cu2+浓度为20 μmol/L时,随着乙酸和苹果酸浓度的增加,对苏柳172和垂柳根系吸收Cu2+的促进作用呈先上升后下降的趋势,其中,乙酸在10:1(乙酸∶ Cu2+)、苹果酸在5:1(苹果酸∶ Cu2+)时促进作用最强。Cu2+在根尖区的含量远远大于成熟区,说明根尖区是吸收Cu2+最活跃的区域。在Cu2+浓度为20 μmol/L的吸收液中加入乙酸或苹果酸(有机酸∶ Cu2+= 10:1)时,苏柳172根尖区的Cu2+含量分别增加了16.5%和33.7%,根成熟区的Cu2+含量增加了23.7%和43.0%,但根尖区和成熟区的Cu2+含量比值分别是1.40 和1.39,略小于不加有机酸时的1.49。乙酸与Cu2+的比例为10:1时,当Cu2+浓度小于20 μmol/L时乙酸促进垂柳根系对Cu2+的吸收,当Cu2+浓度大于20 μmol/L时,乙酸抑制垂柳根系对Cu2+的吸收,抑制作用随Cu2+浓度的升高而加强,说明低浓度的乙酸可以促进垂柳根对Cu2+的吸收,而高浓度的乙酸能够抑制垂柳根吸收Cu2+。同时,乙酸抑制了Cu2+在垂柳地上部的积累,抑制作用随着Cu2+浓度的增加而加强,说明乙酸能够抑制Cu2+由根向地上部的运输。  相似文献   

8.
Na2CO3胁迫对黄瓜幼苗生长及生理指标的影响   总被引:3,自引:1,他引:2  
以‘津优一号’和‘春四’黄瓜为实验材料,采用砂培法研究了Na2CO3胁迫对黄瓜幼苗生长及生理指标的影响。结果显示,随着Na2CO3浓度的增大,两个黄瓜品种的幼苗根冠比逐渐下降,叶绿素含量先上升后下降,可溶性糖含量、脯氨酸含量、SOD活性逐渐上升;‘津优一号’的相对电导率和丙二醛含量随Na2CO3浓度的增大逐渐增加,而‘春四’的相对电导率和丙二醛含量在20 mmol.L-1时最低,此后逐渐上升。主成分分析结果显示,丙二醛含量、SOD活性、可溶性糖含量、脯氨酸含量、叶绿素b,这5项指标在评价黄瓜幼苗的Na2CO3耐性方面是比较重要的。结合这5项指标综合分析,发现‘津优一号’较‘春四’有较强的耐碱性。  相似文献   

9.
燕麦幼苗对盐胁迫的响应及过氧化氢对响应的调节   总被引:1,自引:0,他引:1  
为了探讨‘定莜6号’燕麦对盐胁迫的生理生化响应及H2O2的调节作用,采用水培方法,研究外源H2O2对盐胁迫下燕麦活性氧代谢、渗透溶质积累和Na+、K+平衡的影响。结果表明:小于100 mmol·L-1Na Cl未对‘定莜6号’幼苗的生长造成明显影响,150 mmol·L-1及以上浓度Na Cl使幼苗干重和叶片K+/Na+显著降低,O2-·产生速率、H2O2、丙二醛(MDA)、可溶性蛋白质和脯氨酸含量及过氧化氢酶(CAT)、质膜H+-ATP酶活性明显提高,但抗坏血酸(ASA)和谷胱甘肽(GSH)含量变化不大;外施5μmol·L-1H2O2可显著缓解150 mmol·L-1Na Cl胁迫对燕麦幼苗生长的抑制作用,使燕麦叶片超氧化物歧化酶(SOD)、抗坏血酸过氧化物酶(APX)和CAT活性及H2O2、GSH含量明显提高,O2-·产生速率和MDA含量显著降低;5μmol·L-1H2O2还提高了150 mmol·L-1Na Cl胁迫下燕麦叶片可溶性蛋白质、可溶性糖、有机酸和脯氨酸含量及质膜H+-ATP酶活性和K+/Na+,降低了游离氨基酸含量;表明外源H2O2可调控燕麦幼苗活性氧代谢和渗透溶质积累,维持K+、Na+平衡,从而增强耐盐性。  相似文献   

10.
为探讨外源一氧化氮(NO)供体硝普钠(SNP)对铜(Cu2+)胁迫的缓解效应,该试验以小桐子幼苗为材料,先通过小桐子幼苗根茎生长指标的变化筛选出后续实验适宜的SNP(0.2mmol/L)和Cu2+浓度(90mmol/L),再进一步考察SNP预处理对Cu2+胁迫下幼苗脯氨酸(Pro)和丙二醛(MDA)的含量及抗氧化酶活性的影响。结果显示:(1)Cu2+处理能诱导小桐子幼苗叶片中Pro和MDA含量显著升高,且过氧化氢酶(CAT)、超氧物歧化酶(SOD)、愈创木酚过氧化物酶(POD)及抗坏血酸专一性过氧化物酶(APX)的活性增强。(2)用SNP预处理能显著提高Cu2+胁迫下幼苗叶片Pro的含量,进一步增强叶片中CAT、SOD、POD和APX活性,降低MDA的含量。研究表明,0.2mmol/L的SNP能够通过提高小桐子幼苗的抗氧化酶活性和游离脯氨酸含量来增强其抗氧化胁迫能力,从而显著缓解Cu2+胁迫对幼苗造成的氧化伤害,维持其正常生长发育。  相似文献   

11.
The ability of Salix aquatica Smith, S. fragilis L. and S. viminalis L. to absorb nitrogen at varied growth rates was investigated in nutrient solutions. The effects of five nitrogen addition rates on growth rates, nitrogen contents of the plants, nitrogen concentration of the media, and dry matter distribution between roots, stems and leaves, were studied.
These clones are highly efficient in absorbing nitrogen at low concentrations in the root medium, independent of growth rate. Strong linear regressions were found between any two of the three factors: relative rate of nitrogen supply (RN), nitrogen content (plant), and relative growth rate (R). Dry matter production per unit nitrogen taken up and unit time (N-productivity) and per unit nitrogen taken up independent of time (N-efficiency) was closely correlated to the nitrogen status of the plant. Root development was favoured in the sub-optimum treatments, and leaf development in the optimum treatments. With regard to their ability to absorb nitrogen, these Salix clones appear satisfactory for efficient short rotation energy forestry.  相似文献   

12.
Salix species are widely used as vegetation filters because of their flourishing root system and fast growth rate. However, studies have yet to determine whether the root system functions in vegetable filters with mixed heavy metal (HM) pollution or whether initial cutting participates in the phytoextraction of HMs. This study aims to determine the function of the root system and initial cutting as vegetation filters in the absorption and accumulation of Cd and Cu. Thick (>1?cm in diameter) and fine (<1?cm in diameter) initial cuttings of Salix matsudana were planted in a nutrient solution with single and mixed (Cd?+?Cu) treatments. The roots of several initial cuttings were removed daily to eradicate rhizofiltration. Results revealed that the existence of the root system altered distribution and interaction of Cd and Cu in plant organs and enhanced tolerance and phytoextraction capacity of plants. The initial cuttings could also absorb and accumulate HMs in the early growth stages of willow without roots. Cu inhibited the plant absorption and accumulation of Cd and promoted Cd transport to shoots. Cd inhibited the Cu absorption of the root system. Our study provided essential data regarding woody species as vegetation filters of HM pollution.  相似文献   

13.
Increased metal tolerance in Salix by nicotinamide and nicotinic acid   总被引:1,自引:0,他引:1  
We have earlier shown that nicotinamide (NIC) and nicotinic acid (NiA) can induce defence-related metabolism in plant cells; e.g. increase the level of glutathione. Here we investigated if NIC and NiA could increase the metal tolerance in metal sensitive clones of Salix viminalis and whether this would be mediated via increased glutathione level. Salix clones, sensitive or tolerant to zinc (Zn), copper (Cu) and cadmium (Cd) were grown in the presence of heavy metals (Cd, Cu or Zn) or NIC and NiA as well as in combination. In addition, the influence of N-acetyl-cystein (NAC) and l-2-oxothiazolidine 4-carboxylate (OTC), stimulators of reduced glutathione (GSH) biosynthesis, and the glutathione biosynthesis inhibitor buthionine sulfoximine (BSO) was analysed. Tolerance was measured as effects on root and shoot dry weight, and the glutathione and metal concentrations in the tissues were analysed. Results showed that NIC and NiA decreased the toxic effects of Cd, Cu and Zn on growth significantly in sensitive clones, but also to some extent in tolerant clones. However, the glutathione level and metal concentration did not change by NIC or NiA addition. Treatment with NAC, OTC or BSO did not per se influence the sensitivity to Cd, although the glutathione level increased in the presence of NAC and OTC and decreased in response to BSO. The results suggest that NIC and NiA increased the defence against heavy metals but not via glutathione formation per se.  相似文献   

14.
A Salix viminalis/gravel system based on hydroponics was developed for wastewater renovation in order to avoid the problems of soil damage and pollution associated with long-term application of wastewater to soil. For such a system to work the mineral elements applied must match closely the requirements of the tree species. To examine this the growth and nutrient uptake of S. viminalis in wastewater was compared with that in Long Ashton nutrient solution (1/4 strength). S. viminalis grew more slowly in wastewater than in Long Ashton solution, but exhibited no obvious deficiency or toxicity symptoms. Since industrial wastewaters often contain metals, the extent to which copper might inhibit wastewater treatment in this system was also examined. S. viminalis was grown in wastewater amended with 10 and 100 ppm copper. Trees were unaffected by wastewater with 10 ppm copper when compared to trees grown in wastewater alone. Wastewater containing with 100 ppm copper was too toxic for the trees to thrive and wastewater treatment was reduced. Treatment efficiencies for unamended wastewater were 57.7% for nitrogen, 90.6% for phosphorus and 24.9% for potassium. These efficiencies are much greater than those quoted for a Salix/soil system, and thus Salix/gravel systems may have potential for wastewater treatment in environmentally sensitive areas or situations.  相似文献   

15.
Abstract

Salix alba L. and Salix fragilis L. are two closely related willow species whose phenotypic features, showing a large and continuous variation, have a low diagnostic value for identifying pure species and interspecific hybrids. In this paper, the effectiveness of different multilocus PCR-based molecular markers, such as I-SSRs, RAPDs and AFLPs in detecting genetic polymorphisms able to discriminate the two willow species was evaluated by analysing a set of 12 reference samples. Three genetic similarity indexes, Dice, Jaccard and Simple Matching coefficient, were used for all possible pairwise comparisons of individuals, revealing the same trend of variation within and between species when different marker systems were used. Cluster analysis, based on Dice genetic similarity coefficient, clustered the individuals of S. alba and S. fragilis into two distinct subgroups, indicating that the gene pools are well differentiated. Moreover, a number of private alleles for each marker system allowed the discrimination of the two species because always present only in one of the two. The utility of different marker systems in discriminating willow species was evaluated by the Polymorphism Information Content (PIC) and the Marker Index (MI) parameters. The variation of Dice's indexes obtained from a different number of experiments in relation to the marker systems is discussed.  相似文献   

16.
用cDNA末端快速扩增(rapid-amplification of cDNA ends,RACE)方法从簸箕柳雄花序中克隆了一个AP3同源基因的cDNA,长826 bp,包括完整的编码区、5′-UTR和3′-UTR,并将其相应的基因命名为SsMADS。该基因由7个外显子和6个内含子组成,编码区长723 bp,编码241个氨基酸,其N-端具有典型的MADS保守结构域。序列分析表明,SsMADS编码的氨基酸序列与毛果杨(Populus trichocarp)AP3同源蛋白有95.7%相似性,与其他几种柳属植物的AP3同源蛋白相似性达96.1%~99.6%。实时定量RT-PCR表明,SsMADS在叶、茎和根中表达量极低,在花序中表达量较高,并且其表达量在花器官的早中期发育阶段逐步提高,说明该基因在簸箕柳花器官的发育中起作用。  相似文献   

17.
Abstract

Non‐destructive assessment of root systems is important in order to understand and optimise the potential of resource capture and allocation by the plant. We studied the relationships between electrical capacitance (EC) and the below‐ and above‐ground biomass of willows. Cuttings of Salix viminalis × Salix schwerinii cv. Olof were maintained in pots and root development was followed up using a portable capacitance meter over the course of 2.5 months. Pot observations were compared with excavation of two‐year‐old established trees. A strong significant linear relationship (R 2 = 0.81, p < 0.001) was obtained between EC and root biomass (dry weight [DW]) for the pot experiment. EC also showed good correlations with stem and leaf biomass, as well as with stem height. In the excavated willow trees, there was a strong logarithmic relationship between EC and root biomass (R 2 = 0.66, p < 0.001). These results suggest that EC is a good estimator of below‐ground biomass in willow and may become useful in screening varieties for differences in root biomass traits, especially in distinguishing below‐ground resource allocation at an early stage.  相似文献   

18.
Seasonal Rhythm of Rooting of Salix atrocinerea cuttings   总被引:1,自引:0,他引:1  
The response of rooting and the content of growth substances in Salix atrocinerea cuttings were studied every month throughout the whole year. To study the rooting response 100 cuttings were put into a rooting mist-propagator frame and the results were observed 30 days later. The hormone content was studied with the same type of cuttings by means of methanol extraction, fractionating into acid, basic and neutral substances and chromatographic analysis on paper and bioassays. Salix atrocinerea cuttings have three rooting phases: one very active in January, February, March and April with plentiful roots, not ramified, originating at the base of the cutting; a second lesser phase from May to August with numerous small and very ramified roots formed at a more ample area on the stalk. Both peaks are separated by a sharp fall in June. From September to December the third phase of rooting takes place. Response is practically nil and the few small roots formed are originated at the base of the stalk, again, as in the first phase. In the histograms a remarkable activity in the acid fraction at Rf = 0.30–0.50 was found and IAA was identified. The rooting capacity of these cuttings and the IAA content show some correlation but not exact enough to assert that the root response is governed by an optimum hormonal content. In Salix atrocinerea cuttings inhibitors are absent during the whole year which support the hypothesis that root formation might in some cases be influenced also by the presence or absence of inhibitory growth substances.  相似文献   

19.
Root-promoting Substances in Salix alba   总被引:1,自引:0,他引:1  
Root-promoting substances were extracted from softwood cuttings of Salix alba L. by centrifuging them with water or by shaking the ground freeze-dried stems with water. Rooting substances were partitioned by paper chromatography or chemical fractionation and their rooting activity was tested by mung bean cuttings. Both extracts indicated three major root -promoting fractions at Rf 0-0.1, 0.7-0.8, and 0.3-0.4 in a decreasing order of their activities when paper chromatographed with isopropanol:ammonia:water 8:1:1 v/v. The strongest one indicated an apparent synergistic rooting effect with indol-3yl-acetic acid (IAA) regardless of the extraction method. These results indicate that water can extract from freeze -dried sample the similar rooting substances found in the centrifugal diffusates. The Rf 0–0.1 fraction consisted of at least four fractions and the strongest one did not move from the starting line on the chromatogram when isopropanol:ammonia:water 8:1:1 was used. This starting line fraction was extremely strong in rooting activity and its highest concentration resulted in 8.7 times as many roots as controls. More thain additive rooting effect between IAA and the fraction was found only at the highest concentration. The fraction was very soluble in water but insoluble in chloroform or ethyl ether and only stimulated rooting of mung bean cuttings when it was applied within 3 days after cuttings were made. It had no effect in lengthening roots. The starting line fraction was further found to have four root-promoting subfractions at Rf 0.05, 0.35, 0.65, and 0.85 when it was chromatographed in 60 % isopropanol. Among these four, the subfractions at Rf 0.65 and 0.35 were strongly root promotive and displayed more than additive root promotion with IAA at the highest concentrations studied.  相似文献   

20.
The authors bring actual state of recent occurrence of the rarest willows species Salix myrtilloides, its critically endangered population from northern part of the Western Carpathians. First original data on recent existence and distribution of the interspecific hybrid Salix × onusta (= S. myrtilloides × S. aurita) completes at the same time knowledge on hitherto unknown past occurrence of S. myrtilloides in the Western Carpathians and extinction of that population.  相似文献   

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