生长调节剂对离体银杏叶苯丙氨酸解氨酶活性的影响

用6种生长调节剂诱导离体银杏(Ginkgo biloba Linn.)叶苯丙氨酸解氨酶(PAL)活性,结果表明:300mg·L-1ETP诱导作用最强,其动态诱导在处理4 h后最高;40 mg·L-1 2,4-D诱导效果最强,并有2个明显的诱导高峰;200mg·L-1CCC诱导作用最强,在处理8 h后出现诱导高峰;除100mg·L-1IAA处理组的酶活性比对照低外,其他浓度的IAA处理均比对照高,诱导作用最强的是70 mg·L-1IAA处理;除了100mg·L-1ABA处理使酶活性略有降低外,其他浓度的ABA处理都能诱导酶活性升高,以75 mg·L-1ABA诱导能力最强,在处理4 h后酶活性最大;4个浓度的GA处理中,仅75 mg·L-1GA处理组的酶活性高于对照,处理8 h后酶活性达到最大.结果说明诱导效果从高至低依次为:乙烯利(ETP)、2,4-D、矮壮素(CCC)、吲哚乙酸(IAA)、脱落酸(ABA)、赤霉素(GA).     

化学调节剂对水稻离体幼穗乙烯生成的影响（简报）

CoCl2、NiSO4及高浓度的GA3抑制水稻离体幼穗乙烯的生成,而2,4-D、Ag2S2O3和乙烯利则明显促进乙烯生成。玉米赤霉烯酮的抑制不明显。精胺和亚精胺的影响不大。     

形成层的来源及功能

形成层是已经分化成熟了的薄壁细胞,经过生理上和形态上的变化,重新恢复分裂机能的次生分生组织。根和茎的不断加粗靠的就是各种形成层的活动。形成层主要有三种类型,即:维管形成层、木栓形成层和额外形成层。它们的发生来源和生理功能是不尽相同的。维管形成层     

旱生植物驼绒藜茎的异常次生结构及其发育

藜科旱生植物驼绒藜(Ceratoides latens)成长茎由木栓组织、异常形成层、不规则排列的异常维管束及其间的木质化厚壁结合组织和中央正常的维管柱所组成。木栓组织很发达。异常形成层连成环状。异常维管束外韧型。结合组织细胞紧密围绕在各个异常维管束之间。正常的次生维管柱由数个扇形维管束组成,位于维管束内的束中形成层已失去分生能力。中央的髓细胞大多破毁。在茎的发育过程中,初生生长和早期的次生生长都是正常的。而以后的次生生长由初生韧皮部外方保留的原形成层细胞发生的异常形成层活动所代替。起初,异常形成层仅向内交替产生结合组织细胞和异常维管束,而后来同时还向外分化木栓细胞。这种异常的次生结构对旱生植物具有重要的生态学意义。     

赤霉素和萘乙酸对柿果实采后成熟软化生理指标的影响

以采后'富平尖柿'果实为试材,常温下用60 mg/L赤霉素(GA3)和20 mg/L α-萘乙酸(NAA)进行处理,考察柿果实成熟软化相关生理指标及果胶物质代谢在贮藏过程中的变化,以明确GA3和NAA处理对柿果实贮藏效果的影响.结果显示:GA3、NAA处理果实的贮藏时间分别比对照延长了4 d和10 d;GA3和NAA处理可显著延缓果实硬度的下降进程,有效降低果实呼吸强度和乙烯释放量,且呼吸高峰和乙烯高峰的出现明显迟于对照;果实多聚半乳糖醛酸酶(PG)活性的升高受到抑制,从而延缓了原果胶的降解以及水溶性果胶含量的增加,阻碍了果实的软化进程.试验表明,GA3和NAA处理可有效延缓柿果实的后熟软化,延长其贮藏期限, 并以GA3的效果尤为明显.     

龙眼剥皮再生的解剖学研究

龙眼(Dimocarpus tongan Lour.)茎干经过大面积环剥,都能再生出新皮。环剥初期,愈伤组织都由近暴露面的射线细胞产生,稍后,其他未成熟木质部细胞也参加愈伤组织的形成,这些愈伤组织一般在靠近表面都可发生木栓形成层,以后迅速形成正常的周皮。在愈伤组织与木质部交界处的未成熟木质部细胞发生维管形成层。新发生的形成层正常地向外分化出次生韧皮部,向内分化出次生木质部。初期有些原来的射线将新形成层带分割成许多小区,二个月后,由于新的形成层不断平周活动,逐渐将形成层连成一圈,以后基本上与正常树皮维管组织的发育一样。     

形成层的结构与活动

高等植物的形成层包括产生维管组织的维管形成层和产生周皮的木栓形成层,但通常将前者简称为形成层。本文讨论的仅限于前者。且形成层的发生与结构图1根和案中形成层的形成A～C．根的中柱横切面A、B形成层片段开始活动并产生次生维管组织C．形成层成为具4个凸起的环状,凹处已逐渐向外推移D．茎的一部份,示束中与未间形成层连成环状形成层通常位于木质部与韧皮部之间,在根、茎中整体呈圆筒状,在叶柄与较粗的叶脉中呈条状。因其位于器官的侧面,又称为侧生分生组织。形成层在个体发生上来源于初生分生组织中的原形成层,在根与茎中还…     

地黄块根的发育解剖学研究

地黄根的初生构造与次生生长的发生类似一般双子叶植物。但在以后的发育过程中,木栓形成层产生了多层栓内层薄壁细胞,维管形成层则产生了大量高度薄壁组织化的次生维管组织,从而形成了肉质膨大的块根。地黄块根的这种形成方式为一种异常生长。     

西洋参根的发育解剖学研究

西洋主根顶端的原分生组织由三群原始细胞组成。初生木质部为三原型。维管形成层产生的次生维管组织中薄壁细胞占主导地位;维管分子量少、聚集成群,分散在薄壁组织中。周皮加、周皮发生较迟,其木栓形成层由紧靠内皮层的皮层细胞产生。不同年龄西洋参主根随着龄龄的增加,周皮、次生真心皮部和木质部面积均呈增加趋势,但韧皮部与木质部面积比值自５：１下降至１：１。一年生根由中柱鞘产生初生分泌道,由维管形成层产生一圈次生分     

黄芩根的解剖学研究

用常规石蜡切片方法对黄芩(Scutellaria baicalensis Georgi)一、二年生主根的发育及结构进行解剖学研究。结果表明,黄芩根的发育可分为原分生组织、初生分生组织、初生结构和次生生长等4个阶段。原分生组织由3群原始细胞组成,其细胞具有典型分生组织的细胞学特征;初生分生组织包括根冠原、表皮原、皮层原和中柱原,其中根冠原和表皮原具有相同的起源。初生结构由表皮、皮层和中柱组成。初生木质部为二原型。次生生长主要是由维管形成层和木栓形成层的活动完成,木栓形成层起源于中柱鞘细胞。二年生黄芩主根的主要结构与一年生的基本相同,其不同之处为:二年生主根的周皮增厚,次生木质部中木纤维成群分布,出现木间木栓;维管射线为多列且明显;在近周皮的韧皮部内出现包围石细胞的木栓环组织。     

The Effects of Several Exogenous Hormones on Bark Regeneration After Girdling in Eucommia ulmoides

When the exposed surface of the girdled trunk of Eucommia ulmoides Oliv. were daubed with plant hormones, i.e. ethrel, 2,4-D, NAA, GA and NAA+GA respectively in appropriate concentrations, it was found that the 2,4-D, GA and NAA+ GA treated trunks, initiations of phellogen and vascular cambium in callus were earlier than that in control. These trunks treated with ethrel, formation of phellogen alone were earlier. However, initiation of phellogen and differentiation of vascular cambium in the trunk treated with NAA were similar to control.     

The Effects of Plant Growth Substances on Rind-Regeneration after Girdling in Solanum melongena cv. esculantum

This paper deals with the effects of four plant growth substances, ic. IAA, NAA, 2,4-D and GA and their different concentration on rind-regeneration after girdling in Solanum melongen var. esculantum. The formation of callus was promoted by IAA, NAA and GA, but retarded by 2,4-D in early stage. The initiation of vascular cambium in callus was retarded by all these substances. However, an increase in amount of xylem was promoted by IAA at low concentrations. The different concentrations of NAA and GA affected a decrease in amount of xylem. The formation of "bundled" vascular tissue was impelled by NAA, GA and 2,4-D. The initiation of phellogen was promoted by IAA and NAA at high concentrtion. In addition, the nest-like tracheid mass was induced in callus by IAA and NAA frequently.     

Lateral meristems of higher plants: Phytohormonal and genetic control

Lateral meristems (pericycle, procambium and cambium, phellogen) are positioned in parallel to the lateral surface of the organ, where they are present, and produce concentric layers of undifferentiated cells. Primary lateral meristems, procambium and pericycle, arise during embryogenesis; secondary lateral meristems, cambium and phellogen, — during post embryonic development. Pericycle is most pluripotent plant meristem, as it may give rise to a variety of other types of meristems: lateral meristems (cambium, phellogen), apical meristems of lateral roots, and also shoot meristems during plant in vitro regeneration. Procambium and cambium developing from it give rise to the vascular tissues of the stems and roots, ensuring their thickening. The review considers the genetic control of lateral meristem development and the role of phytohormones in the control of their activities.     

Histological study of callus formation and root regeneration from mung bean (Vigna radiata W.)

We have established a reproducible culture system for callus formation and root development from juvenile stem segments of mung bean(Vigna radiata). In particular, we have studied the influence of plant growth regulators. Induction of calli from young stem explants was very effective on MS inorganic salts supplemented with 0.5 mg/L 2,4-D and 1.0 mg/L kinetin. In regenerating adventitious roots from callus tissues, we found that a combination of 0.75 mg/L NAA, 1.5 mg/L kinetin, and MS salts resulted in 20% efficiency. Histological examination showed that callus tissues originated from out-growths of the cambium rings through de-novo meristematic activity. Those rings were localized outside the vascular cambium. Adventitious roots that developed from root primordia originated from the center of the Callus masses. These primordia produced tracheid-like cells, which then became meristemoid cells for the cambium. Newly formed adventitious roots had the typical tetrarche actinostele type.     

Studies on anther cultures of tomato —Lycopersicon esculentum Mill

The anthers of three genotypes ofLycopersicon esculentum, viz. cv. HS-101, cv. HS-102 and an F₁ hybrid (Montfavet 63-4xHS-101) in different stages of development were cultured in various defined nutritive media. Only anthers containing microspores in the early uninucleate stage were found to respond with the culture medium in the formation of androgenic callus. The DGII medium with 2 mg l⁻¹ NAA and 1 mg 1⁻¹ kinetin was found to be best for callus induction but MS medium supplemented with 2 mg l⁻¹ 2,4-D and 0.1 mg 1⁻¹ BAP favoured proliferation and growth of the callus. The androgenic microspores followed the ‘B’ type pathway of androgenesis in the formation of callus. Induction of tracheids in the callus could be achieved by supplementing the basal medium with NAA and kinetin or 2,4-D and BAP. Initiation of vessel elements and cambium were favoured by addition of NAA and kinetin and that of the phloem in the presence of 2,4-D and BAP in the basal medium, suggesting that the hormonal requirements for production of different elements of the vascular system in androgenic callus are different. Although roots could be induced from the callus, shoot differentiation could not be achieved under cultural conditions.     

Growth Hormones and Propagation of Cymbidium in vitro

Protocorms of Cymbidium (Orchidaceae) were grown on solid or liquid medium with macro-nutrients according to Wimber (van Raalte 1967) and iron, micro-nutrients and vitamins according to Nitsch (1968) the medium also contained 2% sucrose. The effects of 1) the auxins; indol-3yl-acetic acid (IAA), α-naphthaleneacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D); 2) the cytokinins; 6-furfurylaminopurine (kinetin) and benzyladenine (BA) and 3) the gibberellin; gibberellic acid (GA) were examined alone or in combinations. IAA had no effect alone. NAA resulted in optimal fresh weight at 10 μM and the protocorms were vigorous, but lighter green than usual. 2,4-D caused a high weight increase at 1 μM, but the protocorms were abnormal. Higher concentrations of NAA and 2,4-D inhibited chlorophyll synthesis. On solid medium kinetin (100 μM) induced a growth of many small shoots, but had no effect on the fresh weight. In liquid medium, kinetin promoted a callus formation and fresh weight increase. BA had effects similar to kinetin, but at lower concentrations. GA alone promoted shoot and leaf growth. Combinations of kinetin and NAA resulted in a maximal fresh weight increase at kinetin concentrations one tenth of the NAA concentrations. The optimal growth and the best development occurred at 10 μM NAA and 1 μM kinetin. NAA and kinetin together could limit the shoot and leaf growth induced by GA.     

Regeneration of fertile plants from protoplasts of sunflower (Helianthus annuus L.)

Summary Sunflower hypocotyl protoplasts (Helianthus annuus L.) from 5 PIONEER genotypes (PT024, SMF3, EMIL, HA300*PT024, VK5F) and 1 public line (RHa 274) formed colonies at frequencies of up to 60% when plated in 0.25ml agarose beads in a modified L4 medium (Lenée and Chupeau 1986) containing 3mg/l NAA, 1mg/l BA and 0.1mg/l 2,4-D, and 1000mg/l casamino acids. Protoplast-derived colonies grew slowly into calli. Organogenesis was obtained from callus of PT024 on a MS medium containing NAA and BA at 1mg/l and GA at 0.1mg/l. Freshly excised shoots were induced to root by an IAA treatment. Regenerated plants were transferred to the greenhouse and seed was harvested within 7 months of the initial protoplast isolation.Abbreviations BA 6-benzylaminopurine - NAA -naphtaleneacetic acid - GA gibberellic acid - IAA indole-3-acetic acid - 2,4-D 2,4-dichlorophenoxyacetic acid - MS Murashige and Skoog mineral elements - B5 Gamborg mineral elements     

Effect of GA3 and 2,4-D foliar application on the anatomy of date palm (Phoenix dactylifera L.) seedling leaf

Two concentrations (10-5M and 10-3M) of both GA3 and 2,4-D were used as foliar spray to evaluate the response of date palm (Phoenix dactylifera L.) cv. Khedri seedlings. They affected some of the anatomical characteristics of the first leaf emerging after the beginning of the spray. The high concentration of GA3 increased the size of the midrib and its vascular bundle numbers. Both low and high concentrations of 2,4-D inhibited the formation of the midrib. 2,4-D in both low and high concentrations decreased the number of vessels in both protoxylem and metaxylem and also decreased their diameters, where as GA3 in low and high concentrations have less effect on the number of vessels and its diameters. GA3 in high concentration increased the number of vascular bundles in 1mm long of the leaf blade, while 2,4-D in low and high concentrations decreased their numbers. 10-3M of 2,4-D increased the size and layers of special hypodermal cells.     

Developmental changes in the secondary xylem ofAcer rubrum induced by gibberellic acid,various auxins and 2,3,5-tri-iodobenzoic acid

Summary The effect of GA on the development of the secondary xylem ofAcer rubrum was studied. GA was applied to seedlings (1) separately, (2) simultaneously with TIBA, and (3) simultaneously with TIBA and an auxin. GA alone is without effect on the development of the secondary xylem. In seedlings treated with TIBA-GA or TIBA-GA-auxin, the differentiation of the xylem elements is in general similar to that of seedlings treated with TIBA or TIBA-auxin respectively. GA however, does stimulate cambial activity in a localized region of the stem if the endogenous rate of cambial division is low.The following abbreviations will be used TIBA (2,3,5-tri-iodobenzoic acid) - IAA (indole-3-acetic acid) - GA (gibberellic acid) - NAA (naphthaleneacetic acid) - 2,4-D (2,4-dichlorophenoxyacetic acid) This material was included in a doctoral thesis submitted by P. R.Morey to the graduate school of Yale University, New Haven.