Regulation of phytohormones on root primordium initiation and adventitious root formation in the etiolated shoots of Paeonia suffruticosa'Yinfen Jinlin'

Tree peony is well known and sought after for its large, colorful flowers. Its propagation is via vegetative methods. Mech- nisms of the adventitious rooting and the regulation of rooting processes are the principles and techniques of plant propagation and improvement. Microstructures and fluctuations of phytohormones in the adventitious rooting were studied with the etiolated soft- wood shoots of Paeonia suffkuticosa ＇Yinfen Jinlin＇. There are no pre-primordia in the shoots of the cultivar. Adventitious roots are produced in five stages： shoot selection, primordium initiation, primordium growth, conducting tissue differentiation and root protru- sion. Primordia initiated in the cortex. The contents of the endogenous hormones, IAA, ABA and GA, were 5.842, 0.873 and 1.043 nmol·g^-1 FW on the bases of shoots, respectively. CTKs which included isopentenyl adenine （iPA）, zeatin riboside （ZR） and dihy- drozeatin riboside （DHZR） were 0.949, 0.695 and 2.034 nmol·g^-1 FW, respectively. DHZR is active among CTKs. The ratio of IAA to GA, CTK and ABA clearly increased at the stage of primordium initiation, while they showed low levels at the stages of primor- dium growth. The ratios were restored at the shoot levels at the stage of root protrusion. IBA provoked primordia initiation in the cortex, the vascular cambium, the pith and even in the callus induced on the base of shoots. ]AA levels in the treated shoots increased gradually to its highest level （three times of control） at the stage of conducting tissue differentiation. The ratios of IAA to GA, CTK and ABA clearly decreased at the stage of primordium initiation. The ratio of IAA to ABA is regulated at 10：1.

In Vitro Propagation of Three Strawberry Varieties and Field Evaluation

A study was done to produce a rapid in vitro propagation of three strawberry genotypes and tested in the field under Bangladeshi circumstances. Festival, RABI-3, and Neho strawberry genotypes’ runner tips were cultivated in vitro to induce root induction and multiple shoot proliferation. MS (Murashige and Skoog) media that were basally containing three different concentrations at 1.0, 1.5, and 2.0 of BA (6-benzyl adenine), KIN (6-furfuryl amino purine), or GA3 (gibberellic acid) at 0.5 mg/L increasing tips of the runner was attained. The culture grew on the medium provided with 1.5 mg/L 6-benzyl adenine and 0.5 mg/L 6-furfuryl amino acid to increase shoot at the best level. Micro-cuttings were rooted on MS media at half strength combined with 0.5 mg/L - 1.5 mg/L IBA (indole butyric acid) or IAA (indole acetic acid). IBA attained 4 - 9 roots and 91% - 96% rooting at 1.0 mg/L. The resulting plantlets grew into hardy plants and took root in the earth. The genotype festival had the highest response rate, followed by RABI-3 and Neho.

Direct Regeneration of Plants Derived from in vitro Cultured Shoot Tips and Leaves of Poplar （Populus×euramericana ＇Neva＇）

The purpose of the present study was to establish a regeneration procedure for Populus × euramericana ＇Neva＇ by using in vitro shoots tips and leaves. For sterilization, 0.1% （w/v） mercuric chloride （HgCl2） solution for 8 to 10 min was the optimal treatment for this poplar cultivation. The effects of benzyladenine （BA） and α-naphthaleneacetic acid （NAA） added to Murashige and Skoog （MS） medium were tested on organogenesis. The highest regeneration rate and numbers of shoots/explant from shoot tips （96.7%, 9.8） and leaves （90.0%, 8.7） were obtained on the half-strength MS medium supplemented with 0.5 mg/L BA and 0.1 mg/L NAA. The optimal medium for in vitro rooting of shoots was on a half-strength MS medium containing 1 mg/L indolebutyric acid （IBA） with the highest rooting frequency （93.3%） and numbers of roots/explant （8.2）. For acclimatization, in vitro rooted plantlets were transferred to plastic cups containing vermiculite and peat （1： 1）. After acclimatization, transplanted plantlets grew well in a shade house. Therefore, we believe that this efficient plant regeneration protocol especially by leaf explants is very important for in vitro clonal propagation of Populus×euramericana ＇Neva＇.

苹果砧木新品种鲁砧1号离体叶片高效不定植株再生

【目的】建立苹果半矮化砧木新品种鲁砧1号离体叶片高效不定梢再生技术体系,为该砧木快繁和遗传改良奠定技术基础。【方法】以鲁砧1号无菌苗离体叶片为外植体,研究碳源、细胞分裂素种类和质量浓度对叶片不定梢再生的影响;以不定梢为试材,研究基本培养基、蔗糖质量浓度对不定梢生根的影响。【结果】MS添加较低质量浓度(0.6 mg·L^(-1))细胞分裂素(TDZ)时,碳源物质为D-山梨醇的叶片不定梢再生率显著高于蔗糖;其他激素处理下,D-山梨醇和蔗糖之间叶片不定梢再生率无显著差异。两种碳源上的平均每叶不定芽(梢)数,都表现较高细胞分裂素质量浓度处理高于或显著高于较低细胞分裂素质量浓度处理,以TDZ质量浓度为1 mg·L^(-1)时产生的不定芽数最多,平均每叶不定芽数为3.8~4个。在不定芽诱导培养基上,6-苄基氨基嘌呤(BA)比TDZ更容易诱导产生直接伸长生长的不定梢。不定梢生根率和平均每株生根条数,两种基本培养基及两个蔗糖质量浓度之间都表现差异不显著,但以1/4MS基本培养基和20 g·L^(-1)蔗糖组合的生根培养基上获得的生根率和单株生根条数最高,分别超过93%和5.8。【结论】鲁砧1号离体叶片容易诱导再生不定芽和不定梢生根,诱导叶片不定芽再生最佳培养基为MS添加1 mg·L^(-1)TDZ、0.3 mg·L^(-1)IBA和30 g·L^(-1)蔗糖,最佳生根培养基为1/4MS添加0.3~0.5 mg·L^(-1)IBA和20 g·L^(-1)蔗糖。

黄刺玫(Rosa xanthina Lindl.)嫩枝扦插生根过程的解剖学研究

文章对黄刺玫嫩枝扦插生根过程中不定根的发生发育进行了解剖学研究,结果表明,黄刺玫插条内未见潜伏根原基,属诱生根原基生根型。黄刺玫的诱生根原基产生于愈伤组织,为较难生根树种。

Study on the Influencing Factors and the Root Mechanism in Cutting Process of Prunus humilis(Bge). Sok

A procedure for cutting Prunus humilis（Bge）. Sok was comprehensively studied in this paper. It was found that the key factors involved in this procession were medium, rooting accelerator, concentration of rooting accelerator and type of shoot. The results showed that send was used as mediums; Treatment with 1 000 mg/L AST rooting powder No. 2 and semi-woody shoots were the optimal materials for cutting, and the rooting rate reached 88.1%. Anatomical study on rooting of Prunus hum#is（Bge）. Sok cutting has been carded out by the paraffin section method. The observation result shows that the adventitious root primordium of Prunus humili$（Bge）. Sok cutting belongs to the type of induced root primordium. The adventitiousroot primordium originates from the cross region of vascular cambium and pith rays.

Non-aerated liquid culture promotes shoot organogenesis in Eucalyptus globulus Labill

Eucalyptus is very recalcitrant to in vitro culture.In this research, an efficient shoot organogenesis system was developed using 60-day-old plants of Eucalyptus globulus grown in vitro and non-aerated liquid medium to improve shoot proliferation. Cultures were initiated with hypocotyls and leaf segments from plantlets cultivated on semisolid 1/2 MS modified medium supplemented with 4.44 μM 6-Benzyladenine(BA) and 16.1 μM 1-Naphthaleneacetic acid(NAA). Calli were transferred to shoot induction medium, with either 0.5 or 2.7 μM NAA. Shoot multiplication was carried out on 4.44 μM BA + 0.5 μM NAA medium, and semisolid and non-aerated liquid systems were compared for improving shoot proliferation.Rooting of adventitious shoots was evaluated on medium containing NAA or Indole-3-butyric acid-IBA(5 and16 μM). Callogenesis was obtained from both types of explants, although shoot formation was only obtained from leaf-derived calli. Shoot proliferation on 4.44 μM BA+0.5 μM NAA resulted in the most shoots/callus.Non-aerated liquid medium was more efficient in promoting shoot multiplication(53.5 shoots/callus) than was semisolid medium(28.5 shoots/callus). Levels of phenolic compounds were significantly reduced in the shoots cultivated in liquid medium. Efficient rooting(76%) was obtained using 16 μM IBA.

Micropropagation of yellow mangosteen:a valuable endemic tree of India

We developed a method for in vitro regenera- tion of Garcinia xanthochymus （yellow mangosteen） from matured seed segments. Multiple shoots were induced on woody plant （WP） medium supplemented with cytokinins. An average of 11 shoots per explant were regenerated from mature seed segments on WP medium containing 20 μM 6-benzylaminopurine. Histological analysis revealed that hypodermal cells of seed segments were initially involved in active division, which later developed into meriste- moids, subsequently leading to the formation of shoot buds. Shoot elongation was achieved by repeated subculturing of seed explants in shoot regeneration medium. Rooting of shoots was achieved on WP medium supplemented with indole-3-butyric acid or s-naphthalene acetic acid. Plant- lets were transplanted to pots containing soil： compost （1：1） and survival rate was 90 %.

The Effects of Auxins and Cytokinin on Growth and Development of (<i>Musa</i>sp.) Var. “Yangambi” Explants in Tissue Culture

The aim of this study was to investigate the effects of concentration of different growth regulators (auxins and cytokinins) on growth and development of banana shoot tips cultured in vitro. Explants were taken from young suckers of field grown plants of var. “Yangambi”. The shoot tips were cultured on MS media supplemented with different concentrations of BAP (0, 2, 4, 6 and 8 mg/l) with or without IAA at concentration of 0.34 mg/l. At the rooting phase, the media was supplemented with different concentrations of IBA (0.1, 0.5, 1.0, 1.5 and 2.0 mg/l) with or without BAP at concentration of 0.2 mg/l. The results indicated that 6.0 mg/l BAP significantly increased the number of shoots formed and the interaction of 6 mg/l BAP with 0.35 mg/l IAA significantly increased the fresh weight. For rooting, 2.0 mg/l IBA was more efficient in number and length of roots produced than all other treatments.

Histological Observation of Somatic Embryogenesis and Adventitious Buds Induction from Ginkgo biloba L.Different Explants in vitro Culture

The differentiation process including somatic embryogenesis in different Ginkgo explants in vitro culture were studied by cytological observation.The results are as follows:1) two complete cotyledons and a embryo bud were observed in mature embryos and several secretory acavitives appeared in maturation region of embryo buds,hypocotyls,cotyledons and radicles after culturing 20 days;two incomplete cotyledons and a embryo bud primordia were found in large cotyledon embryos.The proembryo of two cells,four cells, multi-cellular,and globular embroy were developed from the callus of the small cotyledon embryos.2) The differentiation of cotyledon explants started from epidermal cells,and gradually formed meristematic cell mass in the cortical cells,and eventually adventitious buds were observed.3) The adventitious roots of Ginkgo originated in the cells at the cross of vascular cambium and vascular rays. 4) The type of rooting belongs to induction type by root primordium.The formed adventitious roots were observed after 20 days.

红花石蒜离体再生技术研究

以3~5年生红花石蒜鳞茎为实验材料,研究不同激素处理和有机添加物对外植体诱导、增殖培养、生根培养的影响,筛选出红花石蒜高效组培再生体系。结果表明:采用双鳞片法,外植体进瓶诱导培养以MS+6-BA 5 mg·L^(-1)+IBA 3 mg·L^(-1)培养基为宜,平均分化芽数为2.53个;愈伤组织进瓶诱导以MS+TDZ 10 mg·L^(-1)+NAA 1 mg·L^(-1)为宜,愈伤组织诱导率达69.05%。芽的增殖培养基为MS+6-BA 5 mg·L^(-1)+IBA 3 mg·L^(-1)+椰汁50 g·L^(-1)最佳,平均分化芽数为4.13个,芽数量多,生长健壮;愈伤组织分化不定芽培养基以MS+TDZ 20 mg·L^(-1)+NAA 1 mg·L^(-1)最好,平均分化芽数为12.83个。最适生根培养基为MS+IBA 1 mg·L^(-1),生根率达100%。通过小鳞茎诱导芽的直接再生和愈伤组织诱导芽的间接再生两种方式获得了红花石蒜离体再生体系,为红花石蒜良种快繁和遗传转化体系构建奠定技术基础。

榆林沙区沙地柏天然林设置沙障与压条更新恢复效果研究

为促进榆林沙区唯一常绿灌木树种——沙地柏天然林更新恢复,选择半固定沙地、流动沙地和丘间地,进行了设置沙障和匍匐茎埋沙对沙地柏植株产生不定根、萌发新枝的效果观察研究,结果为在试验的3种环境和2种技术条件下,不管是迎风坡、流沙坡的中部及下部,还是丘顶或沙梁,沙地柏都会产生不定根、萌发新枝,且生长正常,沙障规格和压条长度、压沙厚度不同不定根及新枝的数量和长度不同。建议在半固定和流动沙地设置规格为1.5 m×1.5 m或为2.0 m×2.0 m的沙障,匍匐茎压条时,以埋沙厚20~30 cm、压条长10~30 cm为宜。

两种椴树嫩枝扦插生根的解剖学研究

对糠椴、蒙椴嫩枝扦插生根过程中不定根的发生发育进行了解剖学研究 ,结果表明 :两种椴树插条内未见潜伏根原基 ,属诱生根原基生根型。糠椴的诱生根原基产生于维管形成层、愈伤组织 ,为较难生根树种 ;蒙椴的诱生根原基产生于髓射线与皮层交界处、维管形成层、愈伤组织 ,为较易生根树种。愈伤生根为两种椴树的主要生根形式。

核桃试管嫩茎生根的形态结构及激素调控研究

以核桃品种‘新早丰’试管嫩茎为试材,对其诱导生根过程中的形态结构及相关的生长素(IAA)和脱落酸(ABA)变化进行了研究。证实诱导生根过程中核桃嫩茎不定根原基发生于形成层,特别是髓射线正对的形成层部分;根原基起始分化期为诱导第6天左右,伸长期是第10天;如果12d之后仍放在诱导培养基中,生根率下降,并且出现茎基愈伤化、茎尖变黑和叶片脱落等现象;若生根诱导10d后转入无植物生长调节剂培养基,培养5d左右可见根尖突出表皮,根系发育正常;同时与不定根形态发生相应的内源IAA和ABA的变化是根原基的发生期和伸长期,内源IAA出现高峰,内源ABA呈上升趋势,IAA/ABA值在根原基的发生前为最大,随后降低。本研究不仅从形态结构证实了二步生根法的合理性,而且从生理学角度阐述了不定根发生的IAA/ABA调控机制。

丹参不定根离体培养的研究

目的:对丹参不定根的离体培养进行系统研究。方法:考察了蔗糖质量浓度、培养基pH、接种、植物生长物质等影响因子对丹参不定根的生长及其次生代谢产物含量的影响。结果:随着蔗糖质量浓度的增加,丹参不定根增殖倍数呈增长趋势,丹参酮的含量呈递减趋势变化,原儿茶醛含量呈折线变化,其中以添加30g·L-1的蔗糖最高;培养基pH为6·5,5·5(或6·0),5·8时分别最有利于丹参不定根的生长、丹参酮ⅡA的合成和原儿茶醛的合成。当接种量为2·5%时,丹参不定根的增殖倍数显著增加;MS培养基中附加0·5mg·L-1KT最有利于丹参酮ⅡA和原儿茶醛合成。结论:蔗糖质量浓度、培养基pH、接种量、植物生长物质显著影响丹参不定根的生长和次生代谢产物的合成。

风箱果组织培养不定芽的试管外生根及植株再生

以风箱果幼苗顶芽为外植体,诱导不定芽,通过试管外生根技术建立植株再生体系。结果表明：以MS+BA1．0 mg·L^(-1)+NAA1．0 mg·L^(-1)为诱导培养基,MS+BA0．8 mg·L^(-1)+NAA0．4 mg·L^(-1)为增殖培养基,MS+IBA0．5 mg·L^(-1)+GA_30．3 mg·L^(-1)为壮苗伸长培养基,效果较好；试管外生根以100 mg·L^(-1)NAA处理30 min效果最佳,生根成活率为93．1%。

核桃品种试管嫩茎生根的研究

以 6个早实核桃 (JuglansregiaL .)新品种为试材 ,对长期继代培养的试管嫩茎的生根进行了研究 ,结果表明 :诱导方法、外源IBA的水平、嫩茎发育状态以及光照条件等对生根具有明显的影响。选取生长旺盛、节间较长、叶较小呈嫩黄绿色的幼态嫩茎 ,采用 2步诱导生根法 ,即黑暗条件下 ,在IBA为 5 0～ 10 0mg·L- 1 的 1 4DKW培养基中诱导 10～ 15d ,而后转移至不含IBA的DKW培养基中 ,利用这一方法顺利地诱导了嫩茎生根 ,在对 6个品种的应用中获得了 6 0 5 %～ 89 7%的生根率 ,平均根数 2 0～ 3 6。生根的嫩茎已成功地进行了下地移栽。同时就根原基诱导过程中嫩茎内源IAA和ABA水平变化进行了研究 。

花生幼叶丛生芽的诱导和高效再生体系的建立

以花生种子无菌条件下萌发4天、7天、10天、27天的幼叶作外植体,分别接种于加有不同激素配方的芽诱导培养基上,1周后叶片伤口处膨大并有黄绿色愈伤组织出现,3周左右可以看到丛生芽点的出现,芽诱导率达85%以上;继代培养4周后转至高浓度BA(10 mg/L)的MS培养基上促进芽伸长;当小苗长至3 cm左右时,移入NAA(1 mg/L)的MS培养基上诱导生根,获得完整的再生植株,再生率可以达到80%以上。

蝴蝶兰花葶的离体培养

蝴蝶兰花梗腋芽培养在含VW无机盐 +肌醇 10 0mg·L-1+VB110mg·L-1+VB61mg·L-1+烟酸1mg·L-1+蔗糖 2 0g·L-1+BA 5 0mg·L-1的培养基上 2 2℃培养 ,可分化出花葶。花葶切片在含MS无机盐+肌醇 10 0mg·L-1+VB110mg·L-1+VB61mg·L-1+烟酸 1mg·L-1+蔗糖 15g·L-1+BA 5 0mg·L-1+NAA0 5mg·L-1的培养基上诱导分化不定芽。不定芽在同一培养基上继代增殖 ,在附加香蕉汁 10 0g·L-1的Hy ponex 1号生根培养基上壮苗生根。

苹果离体新梢外植体继代培养次数对其再生的影响

对不同继代培养次数的富士、金冠、乔纳金苹果(Malus domestica Borkh.)组培离体新梢外植体分别进行新梢增殖倍数、生根和叶片不定芽再生能力研究。结果表明,3个品种无菌繁殖系建立后第5次继代培养的离体新梢外植体的增殖倍数、生根和叶片不定芽再生能力均较低;随继代次数增加,以上各种器官再生能力稳定在较高水平,继代76、164代的富士及76、84、116代的金冠和乔纳金新梢外植体间均无明显差别。说明苹果新梢外植体达到离体培养状态后经20年100余次继代培养,其器官再生能力没有显著变化。