多效唑对盆景榔榆生长的作用（简报）

盆景榔榆施用多效唑后,对其当年及次年的生长均有显著抑制效应。在50～200ppm 浓度范围内,随处理浓度递增,新梢生长量、叶面积减小,叶片厚度、叶绿素含量增加。处理株与对照相比,叶片内源激素IAA,GA_3的含量明显减少,ABA含量增加。     

施硼和赤霉素对‘李广杏’坐果率及果实品质的影响

该研究以8年生盛果期的‘李广杏’植株为试材,于花蕾膨大期喷施0.1%(P1)、0.3%(P2)和0.5%(P3)硼砂和盛花初期喷施50(C1)、100(C2)和150 mg/L(C3)赤霉素,测定不同处理下李广杏的坐果率、果实品质及营养生长指标的变化,并用主成分分析不同处理的效果进行综合评价,为敦煌寒旱区‘李广杏’的栽培提供理论依据。结果表明:(1)‘李广杏’叶面积增长量在C1浓度处理下显著高于CK,不同浓度的硼处理对其均具有抑制作用,但C1、P2浓度下新稍生长量高于其他处理。(2)适宜浓度的硼和赤霉素处理可一定程度减少‘李广杏’花的败育率,从而有效提高果树的坐果率,其中硼处理以P3浓度下最优,但P3与P2处理下坐果率无显著差异,赤霉素处理以C2浓度下最优。(3)适宜浓度硼和赤霉素能够明显提高‘李广杏’果实品质,C1浓度处理下的果实糖酸比、可溶性固形物含量显著高于CK,P2处理下的果实维生素C、可滴定酸含量显著高于其他处理;适宜浓度赤霉素和硼对果实的单果重、果形指数、侧径有明显的促进作用。(4)主成分分析结果显示,各处理效果的综合得分由高到低依次为P2(1.20)>C2(0.91)>P1(0.13)>C1(-1.01)>CK(-1.68)>P3(-2.13)>C3(-7.76);果实可溶性糖、可溶性蛋白、糖酸比等主成分占比较高,可作为评价‘李广杏’果实品质的重要依据。研究发现,花期喷施适宜浓度的硼和赤霉素可有效提高‘李广杏’果树的生长状况、坐果率及果实品质,且甘肃敦煌地区以花蕾膨大期喷施0.3%硼和盛花初期喷施100 mg/L赤霉素效果最佳。     

多效唑和缩节胺对现蕾前忍冬枝叶生长及花蕾性状和有效成分含量的影响

以忍冬品种‘九丰一号’(Lonicera japonica‘Jiufeng 1’)为实验材料,采用叶面喷施方法研究了不同质量浓度多效唑和缩节胺对现蕾前(抽枝生长初期)枝叶生长和叶片叶绿素含量以及花蕾性状和花蕾中绿原酸和总黄酮含量的影响。结果显示:分别喷施100、400、700和1 000 mg·L-1多效唑和50、100、150和200 mg·L-1缩节胺后,多数处理组的开花枝条数、着花节数和叶绿素含量较对照CK1(水)有不同程度提高,但叶面积差异不明显。随处理时间延长,各处理组枝条节间长度总体上呈逐渐增加的趋势,其中多数处理组枝条节间长度增长缓慢。各处理的花蕾长度、百蕾鲜质量和干质量总体上小于CK1,而花蕾折干率、总黄酮含量和绿原酸含量显著或不显著高于CK1。此外,在喷施多效唑和缩节胺的同时喷施质量体积分数1.0%尿素和质量体积分数0.1%硼砂,忍冬的叶面积、着花节数、花蕾长度、折干率、百蕾鲜质量和干质量总体上有所提高,而绿原酸含量降低,但各指标的差异总体较小。研究结果表明:喷施适量多效唑和缩节胺可调控忍冬枝条生长,并能提高花蕾中总黄酮和绿原酸含量。     

NAA与PP_(333)对茉莉新梢部分生理生化作用的影响

在茉莉开花前期分别使用不同浓度NAA(20、50、100mg/L)与PP333(100、300、500mg/L)溶液均匀喷施于植株茎、叶片等生长部位,研究其对茉莉开花的影响,分析测定植株新梢生长部位的可溶性蛋白质、游离氨基酸含量以及保护酶活性等生理生化指标。结果表明:NAA处理使新梢徒长;PP333处理的茉莉,花蕾盛开期比对照提早4d,浓度以300mg/L为宜,其产量比对照增加12.95%,明显提高花蕾产量。茉莉经PP333处理后,新梢可溶性蛋白质和游离氨基酸含量在整个花芽生长过程中趋于相对稳定,而NAA处理后则使可溶性蛋白质和游离氨基酸含量变化幅度大。NAA与PP333处理后新梢中POD活性在花芽生长过程中稍有下降,NAA处理高于对照,而SOD活性则有上升趋势。经NAA和PP333处理后,其效应各不相同,而适宜浓度的PP333处理可以提高茉莉花蕾产量。     

鄂尔多斯高原沙柳幼苗对模拟降水量变化的响应

鄂尔多斯高原是中国干旱、半干旱沙区典型沙地。随着未来全球变化,尤其降水变化进一步激烈,将给这里的陆地生态系统分布格局和生产力带来巨大影响,选择鄂尔多斯高原优势灌木沙柳为研究对象,人为控制４种供水量水平来探讨沙柳幼苗对模拟降水量变化的响应,结果表明,幼苗净光合速率、蒸腾速率、气孔导率和荧光效率随着供水的增加而增大,而供水对幼苗的水分利用效率影响不显著;不同供水量的沙柳幼苗树高、枝条数、叶数和叶面积生长动态存在明显差异,随着供水量的增加,沙柳幼苗树高、基径、枝条数、叶数、叶面积、生物量干重和冠根生物量干重比值均逐渐增大;供水显著增加了沙柳幼苗总分枝率、各级枝条数、枝条长度和叶面积。     

不同整地施肥措施对银杏构件生长及药用成分的影响

研究了田间条件下不同整地施肥措施对银杏构件生长及药用成分的影响．结果表明,对银杏株高生长促进作用最大的措施依次为：施农家肥+间作>爆破整地+间作>施农家肥>爆破整地>间作,提高生长量分别为14．5％、8．6％、5．7％、3．2％和0;对银杏当年新梢生长促进作用最大的措施依次为：施农家肥+间作>爆破整地+间作>间作>施农家肥>爆破整地,提高生长量分别为58．1％、36．6％、33．1％、30．2％和14．0％;不同的整地、施肥和间作措施样地长枝数无显著差异,而短枝数量与总叶数有显著差异;施农家肥加间作措施对提高银杏药用成分含量作用最大,叶片中懈皮素和芦丁含量分别为对照的4．2倍和2．2倍．     

氮、磷养分对飞机草营养器官表型可塑性的影响

采用温室盆栽试验研究了不同氮、磷水平对入侵植物飞机草(Chromolaena odorata)营养器官表型可塑性的影响。结果表明:随着氮、磷水平的上升,飞机草的分枝数量、分枝长度、叶片数、总叶面积、总生物量以及茎、叶器官生物量显著增加。飞机草的根生物量比、根冠比随着氮、磷水平的升高显著下降;茎生物量比在供氮(磷)量达0.05 g·kg-1时显著增加,之后保持稳定;叶生物量比随氮水平的增加先降后升,但其受磷水平变化的影响较小。叶面积比、叶根比、比叶面积和平均相对生长速率随着氮、磷水平的上升显著增加,但叶面积比、叶根比和比叶面积在供磷量≥0.05 g·kg-1时的差异不明显。飞机草的分枝数量、分枝长度、叶片数、总叶面积、根生物量比、根冠比、叶根比以及茎、叶与植株总生物量等指标的可塑性指数较高,并且对氮素的响应更强。表明氮、磷水平能够显著影响飞机草的植株生长,飞机草亦能够通过植株形态、结构以及生物量积累与分配的调整来适应多变的养分环境,并表现出较高的可塑性。     

不同透光率和土壤含水量对夏蜡梅枝条生长量及叶片部分生理指标的影响

采用盆栽实验方法,研究了不同透光率(100%、50%、25%和15%)和土壤含水量(10%、25%、45%和65%)对夏蜡梅(Sinocalycanthus chinensis Cheng et S. Y. Chang)枝条生长量和叶片部分生理指标的影响,并对枝条生长量和叶片各生理指标间的相关性进行了分析.结果表明:在土壤含水量10%或全光照(透光率100%)条件下,夏蜡梅枝条生长量和叶片的叶绿素含量最低,MDA和可溶性糖含量以及SOD和POD活性均较高,脯氨酸和可溶性蛋白质含量最高;在透光率50%和25%或土壤含水量 25%和45%的条件下,枝条生长量和叶片的叶绿素含量提高,其他各项生理指标则有所降低;在透光率15%或土壤含水量65%的条件下,枝条的生长量和叶片叶绿素含量略有减小,其他各项生理指标则有所提高.总体上,随透光率的提高和土壤含水量的减小,夏蜡梅枝条生长量和叶片叶绿素含量呈逐渐减小的趋势,其他各项生理指标呈逐渐提高的趋势.透光率和土壤含水量对夏蜡梅枝条生长量及叶片的生理指标有交互作用,遮阳可在一定程度上缓解土壤干旱胁迫对夏蜡梅的伤害,增加土壤含水量也可在一定程度上缓解强光照对夏蜡梅的伤害;但透光率过低(15%)或土壤含水量过高(65%)则不利于夏蜡梅的生长.相关性分析结果表明,枝条生长量与叶片POD活性、脯氨酸和MDA含量呈极显著的负相关(P＜0.01),说明在胁迫条件下叶片这3项指标的变化与夏蜡梅枝条生长紧密相关,可通过这些指标判定夏蜡梅对其生境的适应程度.根据实验结果推测,在夏季高温阶段,夏蜡梅适宜在透光率50%、土壤含水量45%的生境中生长,在上海地区种植夏蜡梅应适当配植乔木和地被植物.     

不同营养元素缺乏对火力楠幼苗生长的影响

采用温室营养液培养法,设置全素、缺氮、缺磷、缺钾、缺钙、缺镁、缺硫、缺铁、缺微量元素9个处理,通过观察幼苗症状,并对生长状况、叶面积、叶绿素、根活力和生物量等进行测定,研究不同营养元素缺乏对火力楠(Michelia macclurei)幼苗生长的影响。结果表明:火力楠幼苗缺氮时症状出现最早,表现最为明显,各缺素症状主要为植株矮小,长势较弱,叶片偏小且呈淡黄色;缺氮对上述各项指标均与对照存在显著差异,对火力楠幼苗的苗高、地径影响最大且均显著低于全素对照,其他缺素对火力楠幼苗在苗高、地径、根活力与叶绿素等差异不显著,但叶面积、生物量和根冠比等存在显著差异。可见,氮素是限制火力楠幼苗生长的主要影响因子。本研究结果可为火力楠幼苗的缺素诊断和合理施肥提供技术参考。     

赤霉素对单头切花菊发育和外观品质的影响

在菊花幼苗定植到短日照处理期间,喷施50、100、150、200mg·L^-1赤霉素的结果表明：菊花发育进程加快,收获期明显缩短,在0-200mg·L^-1赤霉素范围内随赤霉素浓度的增加,发育进程加快明显,200mg·L^-1赤霉素处理的所需天数最短。株高、花径和花梗长度的生长受到促进,茎粗和叶片数生长受抑。     

巴西橡胶树赤霉素信号转导途径HbRGA1结构和功能分析

DELLA蛋白是赤霉素激素信号负调控因子,具有抑制植物生长发育的作用。解析其家族成员结构与功能将有助于揭示橡胶树DELLA蛋白家族成员调控橡胶树生长发育的机制。本研究从橡胶树热研73397叶片中克隆HbRGA1的cDNA全长序列。该基因长为2136 bp,含1839 bp的ORF,编码613个氨基酸。HbRGA1蛋白序列包含DELLA和GRAS保守结构域,与杨树、木薯和橡胶树DELLA基因相似性高达82.5%。qRT-PCR分析发现HbRGA1在橡胶树叶片中表达量高,在树皮和胶乳中表达量极低。叶片中HbRGA1表达量受喷施赤霉素和脱落酸等诱导显著上调。本研究表明HbRGA1与橡胶树赤霉素等激素信号密切相关,为深入研究其在橡胶树生长发育中的结构和功能打下良好基础。     

非洲菊微管相关蛋白基因GMAP65-1功能分析

微管相关蛋白在植物生长发育过程中发挥重要作用。利用反转录聚合酶链式反应(RT-PCR)和快速扩增cDNA末端(RACE)技术对非洲菊(Gerbera hybrida)体内微管相关蛋白GMAP65-1基因进行了克隆, 获得的基因全长1 883 bp, 包含 1 740 bp的完整开放阅读框(ORF)。表达模式研究表明, 该基因在非洲菊幼嫩的根、叶及花中均有较高的表达, 且受到赤霉素(GA)诱导显著上调。构建GMAP65-1超表达载体, 经异源转化拟南芥(Arabidopsis thaliana)后筛选获得纯合株系, 对纯合株系进行表型观察。结果表明, GMAP65-1超表达植株的叶片及花瓣面积增大, 暗示该基因参与叶片及花瓣的形态建成。研究结果为花卉分子育种提供了理论依据及基因资源。     

Control of bud inhibition in Cyperus

Summary The axillary buds in the leaf crown of Cyperus alternifolius seedlings remain completely inhibited although the shoot is determinate and has no active apex. Buds can be released by detachment of the crown from the plant or by direct application of aqueous enzyladenine (BA), and grow out as inflorescences or vegetative shoots. These arise from activated growth centers of the primordial reproductive branch system which is enclosed within the prophyll of the inhibited bud. Buds are also released by the growth retardant, (2-chloroethyl) trimethylammonium chloride (CCC). Gibberellic acid maintains bud inhibition in detached crowns and inhibits bud release caused by CCC or BA. Naphthaleneacetic acid somewhat reduces BA-induced bud release and causes abnormal root proliferation in CCC-treated crowns. It is suggested that a high level of gibberellin within the crown, possibly in relation to a low level of cytokinin, maintains bud inhibition.     

Effect of Gibberellic Acid on Growth, Gibberellin Content, and Chlorophyll Content of Leaves of Potato (Solanum tuberosum)

Spraying potato plants with a solution of gibberellic acid (GA)when the 15th leaf was emerging increased the area of this leafand its total gibberellin content, assayed by dwarf French beanleaf disks. GA, assayed by lettuce hypocotyls, was not detectedin leaves from untreated plants. The GA content of leaves fromGA-treated plants decreased after 2 weeks and none was detectableafter 5 weeks; apparently it was converted to another gibberellin,possibly the same as the natural gibberellin. GA increased chlorophyllcontent per leaf but increased leaf area more so that the chlorophyllper unit area decreased, and the leaves were paler than untreatedleaves.     

Ancymidol-enhanced hyperhydric malformation in relation to gibberellin and oxidative stress in liquid-cultured <Emphasis Type="Italic">Narcissus</Emphasis> leaves

Summary The growth retardant ancymidol inhibited gibberellin biosynthesis and enhanced hyperhydric malformation of Narcissus leaf sections cultured in liquid medium. Superoxide dismutase activities were examined by spectrophotometry and native polyacrylamide gel analysis, and gibberellin and hydrogen peroxide levels were determined spectrophotometrically in either hyperhydric or non-hyperhydric leaf sections. In ancymidol-treated hyperhydric leaf sections, superoxide dismutase activity and hydrogen peroxide levels were higher during the initial culture period, when hyperhydric malformation occurred, than in control untreated leaf sections. At a later stage, when the meristematic centers started to form on ancymidol-enhanced hyperhydric leaf sections, superoxide dismutase activity, hydrogen peroxide, and gibberellin levels were significantly lower in hyperhydric leaf sections than in non-treated leaf sections. The changes in superoxide dismutase activities, hydrogen peroxide, and gibberellin levels appeared to be related to hyperhydric malformation and meristematic center initiation.     

Phytochrome and hormonal control of expansion and greening of etiolated wheat leaves

Summary Unrolling of etiolated wheat leaf segments is stimulated by short periods of exposure to red light. Both gibberellic acid and kinetin will stimulate unrolling in the dark, whereas abscisic acid (ABA) inhibits the unrolling response to these two hormones and to red light. Exposure to 5 minutes of red light leads to a rapid increase in endogenous gibberellin levels in etiolated wheat leaves, and this increase is followed by a rapid decline. Pre-treatment with ABA inhibits the increase in gibberellin levels in response to red light, but the ihibitory effect of ABA on unrolling cannot be ascribed only to its effect on gibberellin levels. Pre-treatment with red light reduces the lag-phase in chlorophyll development when wheat leaf segments are subsequently exposed to white light; the effect of red light may be replaced by pre-treatment with kinetin, but gibberellic acid is relatively ineffective in this respect.     

The role of abscisic acid and plant growth regulators in tissue culture-induced rejuvenation of strawberry ex vitro

Plant growth regulators applied in vitro affected strawberry plant performance ex vitro for a period of up to 4 months. Benzyl-adenine and gibberellin enhanced juvenile characteristics; in general, more runners and monofoliolate leaves were produced, net photosynthesis was reduced, leaf diffusive resistance was increased and, on occasion, flowering was delayed. In contrast, abscisic acid and a gibberellin biosynthesis inhibitor, paclobutrazol, resulted in a more adult phenotype; specifically, flowering was earlier, net photosynthesis and leaf diffusive resistance rates were equal to those of adult plants, and fewer leaves were monofoliolate. Tissue culture-produced plants reacquire the adult phenotype earlier than seedlings mature. Abscisic acid application to seedlings also resulted in earlier and increased flowering.Endogenous abscisic acid concentrations were greater in adult plants and less in tissue culture and seedling plants at 3 and 7 weeks ex vitro, after germination or after adult runner propagation. No flowering occurred at 3 weeks in any propagation type and only runner-produced plants flowered at 7 weeks. At 15 weeks, no statistical difference in abscisic acid concentrations existed among propagation treatments and all propagation types flowered. The endogenous concentrations of abscisic acid in plants propagated by all three methods were much higher at three weeks compared to concentrations at 7 or 15 weeks.Abbreviations ABA +cis, trans-abscisic acid - BA benzyl-adenine - GC-SIM-MS combined gas chromatography-selected ion monitoring mass spectrometry - GA gibberellin A₃ - RS leaf diffusive resistance in sec cm^-1 - MS Murashige & Skoog medium devoid of plant growth regulators - Pn net photosynthesis in mol CO₂ fixed m^-2 sec^-1 - paclo paclobutrazol as 50WP - TC-plants plants produced from tissue culture - Tween20 polyoxyethylene-sorbitan monolaurate - RP runner plants - SDLG selfed seedlings     

Interaction of gibberellic acid and photoperiod on leaf sheath elongation in normal and gibberellin-insensitive genotype of wheat

Effect of gibberellic acid (GA₃) on leaf sheath elongation in a normal (cv. Møystad) and a gibberellin(GA)-insensitive (cv. Siete Cerros) genotype of wheat ( Triticum aestivum L.) were studied at 18 and 12°C under short (SD, 12 h) or long (LD, 24 h) photoperiod. Leaf sheath length in cv. Møystad was signficantly increased by exogenous GA₃ both under SD and LD. LD alone stimulated leaf sheath elongation and the combined effect of LD and GA₃ was additive, and there was no statistically signficant interaction between photoperiod and GA₃ concentrations. Leaf sheath length in cv. Siete Cerros was not significantly affected by GA₃ under any conditions. However, there was a highly significant stimulation of leaf sheath elongation by LD in cv. Siete Cerros as well. These results indicate that stimulation of elongation growth in wheat leaves by LD is not mediated by gibberellin.     

Hormonal Regulation of Source-sink Relationship: Effect of Hormones on Excised Source and Sink Organs of Cereals

The regulatory role of plant growth substances in relation tosource and sink activity was studied. Leaching of electrolytesfrom flag leaf cells increased with age. Abscisic acid, however,increased the permeability of leaf cells at 10^–4 M andlower concentrations. Plant growth regulators like auxin, gibberellinand cytokinin at 10^–5 M inhibited the leaching of electrolytesbut slightly enhanced the process at 10^–3 M. The effluxof ¹⁴C-sucrose loaded on the flag leaves was not detectablein the very early stage of panicle development but was prominentin the later stages. While auxin prevented sucrose efflux atall stages of panicle development, gibberellin and cytokininwere effective only in different degrees. All the three growthregulators enhanced the activity of -amylase in the flag leafcells but protease activity was enhanced only by gibberellin.Synthesis of polymers like starch, DNA, RNA and protein in developingrice grains was stimulated by gibberellin, cytokinin and auxinlargely in the order mentioned. (Received September 2, 1986; Accepted May 22, 1987)     

Effect of the Rht3 dwarfing gene on dynamics of cell extension in wheat leaves, and its modification by gibberellic acid and paclobutrazol

The second leaf of wheat was used as a model system to examinethe effects of the Rht3 dwarfing gene on leaf growth. Comparedto the rht3 wild type, the Rht3allele decreased final leaf length,surface area and dry mass by reducing the maximum growth rates,but without affecting growth duration. Gibberellic acid (GA₃)increased final leaf length and maximum growth rate in the rht3wild type, but was without effect on the Rht3 mutant, whichis generally regarded as being non-responsive to gibberellin(GA). Paclobutrazol, an inhibitor of GA biosynthesis, decreasedfinal leaf length and maximum growth rate in the rht3 wild typeto values similar to those in the untreated Rht3 mutant. NeitherGA₃ nor paclobutrazol affected the duration of leaf growth.The decrease in leaf length was produced by reduction of celllength rather than cell number. The maximum relative elementalgrowth rate (REGR) for cell extension was essentially the samein all treatments, as was the time between the cells leavingthe meristem and achieving maximum extension rate. The differencesbetween the genotypes and treatments were all almost entirelydue to differences in the time taken from the attainment ofmaximum REGR of cell extension to the cessation of extension.This was reflected in the length of the extension zone, whichwas approximately 6–8 per cent of final leaf length. Theeffects of the Rht3 allele, GA₃ and paclobutrazol all appearto be on the processes which promote the cessation of cell elongation. Key words: Cell extension, gibberellin, leaf growth, Rht3 gene, Triticum, wheat