In vitro propagation of watermelon

A 3-stage, in vitro propagation system for diploid watermelon (Citrullus lanatus (Thumb.) Matsum. and Nakai) has been developed which is also applicable to the economic production of triploid (seedless) watermelon transplants.Stage I involves the stimulation of axillary-bud development from excised seedling shoot tips (1–3 mm) by a high cytokinin (K)/low auxin (IAA) ratio (4.6 μmol/l K 0.28 μmol/l IAA) on a modified Linsmaier and Skoog medium. An average of 4.5 axillary shoots of sufficient size to subculture (> 15 mm) were obtained from each explant in 5 weeks. These shoots were induced to root during 3 weeks subculture on Stage II medium containing 11.5 μmol/l IAA. Well-rooted plantlets were successfully transplanted to a 1 : 1 peat : sand (v/v) substrate and gradually “hardened-off” to greenhouse conditions (Stage III) for 3 weeks, after which they could be transferred to field conditions.Alternatively, axillary shoots from Stage I could be returned to fresh media with 9.3 μmol/l K and 0.28 μmol/l IAA, where an average of 10.3 axillary shoots could be obtained after 5 weeks.Cost estimates for producing 10 000 finished transplants per week project an approximate cost of 16 dollar cents per transplant.     

美国苹果抗性砧木试管快繁技术研究

取美国苹果抗性砧木茎段做外植体 ,探讨了其离体快速繁殖技术 ,筛选出最佳增殖、生根培养基 ,找出了影响试管苗移栽成活率的因素。培养基MS +BA 0 .8mg/L +IBA 0 .1mg/L +白糖 30 g/L +琼脂 6 g/L ,pH值 5 8,适宜MK1,砧木基段培养 ,而MS +BA 0 .8mg/L +IBA 0 .0 5mg/L +白糖 30 g/L +琼脂 6 g/L ,pH值 5 8,对MK2 砧木较合适。试管苗增殖系数达到 8左右 ,生根率 93 9% ,移栽成活率 95 %以上     

In vitro propagation of Symphytum species

Methods are described for the in vitro propagation of Symphytum × uplandicum Nyman from bud, root and stem explants. Highest shoot numbers were produced from root explants > 4 mm in diameter, cultured vertically with their distal cut surface on the medium. The most suitable medium for shoot production was Murashige and Skoog's (MS) with 0.3 mg l⁻¹ 6-benzylaminopurine (BAP). These shoots developed roots on MS medium without hormones and were successfully transplanted into pots. Subculturing shoots onto MS medium containing BAP, kinetin (K), 6-λ,λ-(dimethylallylamino)-purine or gibberellic acid (GA₃) at 0.5, 1.0, 5.0, 10.0 or 30.0 mg l⁻¹ failed to stimulate outgrowth of axillary buds in culture. In vitro propagation from root explants was also achieved with S. asperum Lepech., S. officinale L. and S. × uplandicum cultivars ‘Bocking 1’, ‘Bocking 2’, ‘Bocking 4’ and ‘Bocking 17’, but not with S. bohemicum, S. grandiflorum DC, S. tuberosum L. or S. × uplandicum ‘Bocking 7’ and ‘Variegatum’.     

In vitro propagation of Pyrus pyrifolia

A micropropagation method for an adult seedling tree of Pyrus pyrifolia Burm. f. is described. Shoot cultures were established and multiplied on media containing benzylamino purine and naphthaleneacetic acid, rooted on media containing naphthaleneacetic acid and phloroglucinol, and transplanted to potting mix. Addition of phloroglucinol to the rooting medium enhanced both the percentage of shoots forming roots and the survival of plantlets after transplantation. However, about 30% of the plants raised in vitro were lost owing to a shoot-collapse which was not prevented by the application of fungicides.Establishment and multiplication of shoot cultures was also achieved with 5 named cultivars of P. pyrifolia, but rooting of the shoots of these cultivars has not been satisfactory.     

In vitro propagation of three endangered cactus species

We tested the feasibility of in vitro culture techniques for the propagation of the three endangered cacti species Escobaria minima (Baird) D. Hunt, Mammillaria pectinifera (Ruempler) F.A.C. Weber and Pelecyphora aselliformis Ehrenberg. Twenty-five MS-based proliferation media were tested in preliminary experiments, with different combinations of the auxin NAA and either of the cytokinins BA, kinetin or TDZ. TDZ induced a good proliferation rate, albeit associated with abundant callus formation and hyperhydricity of axillary shoots. A high multiplication rate combined with good quality proliferated shoots and little or no callus induction was observed on media containing BA for E. minima and M. pectinifera and on a medium containing kinetin for P. aselliformis. These results were also confirmed in subsequent experiments in which different explants (shoot tips, bases and longitudinal sections) were used. Micropropagated plantlets were successfully restored to the field, where they reached the flowering stage. Plantlet regeneration of M. pectinifera and P. aselliformis from callus induced on media containing TDZ, but not 2,4-D, was also achieved.     

In vitro propagation of garlic by shoot proliferation

Shoot buds (5–8 mm long), excised from dormant cloves of the New Zealand commercial garlic (Allium sativum L.) and a virus-free French cultivar ‘Rose-de-Kakylis’, proliferated both axillary and adventitious shoots on B-5 basal medium supplemented with 0.5 mg l^?1 isopentenyladenine (2-ip) and 0.1 mg l^?1 naphthaleneacetic acid (NAA). An 8-fold increase in shoot number occurred every 6 weeks. Shoots were readily rooted in B-5 + 0.01 mg l^?1 2-ip + 0.2 mg l^?1 NAA and transferred to pots, where about 70% of the shoots formed established plants. The plants raised by this shoot-proliferation method retained the diploid condition of the parents.     

In vitro propagation of Blandfordia grandiflora (Liliaceae)

Multiple shoots were obtained when single shoot tips of Blandfordia grandiflora were exposed to different concentrations of kinetin, N6~ benzylaminopurine (BAP) and N6- isopentenylaminopurine (2iP). The best multiplication results were obtained when explants were subjected to kinetin at 8 (iM BAP at 0.5,2 and 8 (iM and 2iP at 2,8,32 and 128 |iM. Preliminary rooting trials were performed with three different auxins: indo- lebutyric acid (IB A), naphthalene acetic acid (NAA) and indole acetic acid (I A A). IB A at a concentration of 8 |iM and IAA at a concentration of 32 |xM gave highest root number, but when transplanted to the glasshouse, the best surviving plantlets were those treated with 2 |xM of IBA or 0.5 μM of IAA.     

黄金梨试管快繁技术研究

取黄金梨茎段作外植体 ,研究其快速繁殖技术 ,筛选出最佳增殖、生根培养基 ,找出了影响试管苗移栽成活率的因素。试管苗增殖系数达到 9左右 ,生根率 93 3% ,移栽成活率 95 %以上     

金丝小枣茎段离体快繁技术的研究

以金线小枣的优良品系Ａ２７为试材，对其茎段组培快繁过程中有关技术进行了研究。结果表明，采接外植体以５月中旬的嫩枝枣头为宜，７天内可生长新芽。继代快繁过程中，附加０．２３ｍｇ．１的ＩＢＡ可促进生根，附加６－ＢＡ０．２ｍｇ ／ｌ＋ＩＢＡ０．５ｍｇ／ｌ则有利于长芽展叶。     

In vitro propagation of Pistacia vera L. from seedling tissues

Proliferating shoot cultures were established from shoot tips and nodal bud segments excised from seedlings germinated aseptically and cultured on Murashige and Skoog medium supplemented with BAP plus NAA. Shoot tip necrosis occurred in some cultures. Cultured shoots were rooted in vitro using MS medium (half strength macronutrients) containing IBA for root initiation, followed by subculture onto hormone-free medium for root development. Rooted shoots were readily established in peat-based compost.     

In vitro propagation of ‘Troyer’ citrange from epicotyl segments

Isolated epicotyl, root meristem and root segment tissues of ‘Troyer’ citrange [Poncirus trifoliata (L.) Rat. × Citrus sinensis (L.) Osbeck] were established in continuous culture to compare their regeneration potential. Callus was obtained from these explants on a Murashige—Skoog (MS) medium containing NAA (10 mg l^?1) and BAP (0.1–10 mg l^?1). Formation of shoots from root segments was direct without callus formation on MS medium containing BAP (10 mg l^?1) and NAA (1 mg l^?1). Shoot formation from epicotyl callus occurred on MS medium containing 0.25 mg l^?1 BAP and 0.1 mg l^?1 NAA. Formation of shoots from epicotyl segments occurred on MS medium containing BAP (0.5 mg l^?1) and NAA (0.1–1.0 mg l^?1), while rooting of regenerated shoots occurred in treatments containing 2.0 mg l^?1 NAA alone. This system provides a rapid method for propagation of ‘Troyer’ citrange.     

In vitro propagation of Gladiolus by precocious axillary shoot formation

Axillary buds excised from corms of 3 cultivars of hybrid Gladiolus were cultured on nutrient medium containing various levels of 6-benzylaminopurine (BAP). BAP prevented dormancy, promoted shoot growth and inhibited root development. These effects were accompanied by precocious outgrowth of axillary shoots which developed into detachable, independent in vitro plantlets which could be serially sub-cultured for further proliferation. The level of BAP required to promote a steady rate of axillary branching was inversely related to its natural propagation rate. Plantlets not sub-cultured on to fresh medium eventually became dormant with the formation of small corms which could be planted in compost.     

转rolA、B、C基因枳橙快繁技术

通过对转rol基因枳橙B、D、E系及对照的高接植株春梢茎段进行萌芽诱导、增殖及试管苗生根成苗的试验,摸索出适宜枳橙快繁各种培养基配方及培养条件。结果表明,以MS+6-BA1mg/L的培养基适合于芽萌发,以MS+6-BA0.5mg/L+NAA0.05mg/L的培养基适合于芽增殖,生根则以1/2MS+NAA0.5mg/L+0.2%活性炭的组合最佳,转基因各系生根率均在93.3%以上,显著高于对照生根率(66.7%)。快繁苗移栽成活率可达90%,目前生长良好。     

In vitro propagation of wavy-leaved Indian paintbrush (Castilleja applegatei Fern.)

Castilleja spp. (Indian paintbrush, Orobanchaceae) are desirable ornamental plants with showy floral bracts that are native throughout much of the western U.S. Propagation of these hemiparasites by seed is usually successful only when a host species is present, and asexual propagation through traditional methods has proven to be extremely difficult. In this study we present an effective shoot culture micropropagation system for Castilleja applegatei Fern., the wavy-leaved Indian paintbrush. In vitro shoot tips of three C. applegatei clones were cultured for 28 days on woody plant medium (WPM) supplemented with four concentrations of each of three cytokinins: 6-benzylaminopurine (BA), 6-(y,y-dimethylallylamino)-purine (2iP) and zeatin. Responding explants, shoot number per responding explant and shoot length were determined. In vitro rooting of microcuttings cultured for 42 days on media containing three concentrations of indole-3-butyric acid (IBA) were also evaluated. A high percent response to shoot induction was observed across all treatments, ranging from 94.5 to 100%. C. applegatei responded best to zeatin, which resulted in both the highest mean shoot number and mean shoot length among the cytokinins tested. The best overall shoot multiplication occurred on media with 4.0 μM zeatin, yielding a mean shoot number of 4.11 and mean shoot length of 3.95 cm. The mean highest rooting response (66.7%), root number (13.21) and root length (2.73 cm) were obtained on WPM supplemented with 10 μM IBA. Significant clone × treatment interactions existed for all variables except mean root number, thus the optimum treatments for both shoot multiplication and root induction were clone-dependent. Rooted microcuttings were acclimated ex vitro with an average success rate of 81.2%. This study demonstrates the considerable potential of an in vitro shoot culture system for the asexual propagation of Castilleja spp.     

苹果枣组培快繁技术研究

以MS为基本培养基 ,取苹果枣萌蘖苗茎段作外植体进行离体快繁研究 ,优选确定了其最佳分化、生根培养基的激素组成及各激素的比例关系 ,并且成功地进行了试管苗的移栽。试管苗繁殖系数达 6 2左右 ,生根率达 91 6 % ,移栽成活率达 98%     

In vitro propagation of the onion Allium cepa by axillary and adventitious shoot proliferation

Shoots and scale-base explants dissected from bulbs of the onion Allium cepa proliferated numerous shoots on nutrient medium containing 1–4 mg/l 6-benzylaminopurine and 0.12–0.5 mg/l 1-naphthylacetic acid. Most shoots arose adventitiously from scale explants or leaf bases, but some precocious axillary branching also occurred. In vitro shoots eventually formed bulbils which proliferated further axillary and adventitious shoots when trimmed and split in half before subculture to fresh medium. Root formation was not entirely suppressed by cytokinin and plantlets could be transplanted successfully to compost.     

Vegetative propagation of Chrysanthemum cinerariaefolium in vitro

In vitro cultivated capitulum explants of Pyrethrum (Chrysanthemum cinerariaefolium Vis.) were induced to develop shoots. These shoots were isolated, treated with auxin and transferred to unsterilized soil. Adventitious root formation occurred and viable plantlets were obtained. Shoot development of other plant species according to this procedure was realized.     

杏组织培养研究进展

综述了杏茎尖培养、胚培养、原生质体培养、离体根叶培养等方面的研究进展情况     

In vitro propagation of Lychnis senno Siebold et Zucc., a rare plant with potential ornamental value

Lychnis senno is a rare and valued ornamental plant. Seed propagation is not efficient because of the low germination rate. To grow commercially L. senno in China, a protocol for in vitro germination and propagation of this species was developed. Various germination rates were obtained by treating seeds with GA₃ during 1–6 months storage period. The highest germination rate reached 19.4% when seeds were treated with 250 mg/l GA₃ and stored for 5 months at 4 °C. Axillary shoot proliferation was induced in the nodal segments of the seedlings on medium containing specific concentrations of BA and NAA [Murashige, T., Skoog, F., 1962. A revised medium for rapid growth and bioassays with tobacco tissue culture. Physiol. Plant 15, 473–497]. Maximum number of shoots was developed on a medium supplemented with 5 mg/l BA and 0.5 mg/l NAA, while the higher shoots were observed on a medium supplemented with 0.5 mg/l BA and 0.05 mg/l NAA. Rooting was induced in 91.7% of the regenerated explants on a half-strength MS medium supplemented with 0.5 mg/l NAA. The plantlets grew well and flowered after transfer to the greenhouse. The chromosome numbers of seedlings and propagated plants were also determined to be 2n = 2x = 24.     

In vitro micropropagation of Ephedra

The in vitro micropropagation of eleven species of Ephedra was investigated. Shoot nodal explants of E. fragilis were cultured on Murashige and Skoog medium supplemented with 3% sucrose, 0.05 jiM 3-indolebutryic acid and 0.0-0.5 |iM kinetin, zeatin or 6-ben- zylaminopurine. In general, the average number of shoots produced per explant increased and the average shoot length decreased with increasing cytokinin concentration. Substitution of 3-indolebutryic acid with 2,4-dichlorophenoxyacetic acid caused callusing and distorted shoot growth. Shoot cultures of ten other species were grown on 0.05 |iM 3-indolebutyric acid with 0.05 kinetin. Indole-3-acetic acid gave healthy rooting. E. equisitina, E. gerardiana, E. minima and E. saxatilis were successfully micropropagated using a single-stage protocol in which shoots were grown and rooted on Sorbarods using half strength Murashige and Skoog medium supplemented with 1% sucrose and 5.0 (iM indole-3-acetic acid. Healthy plantlets were weaned in John Innes No. 1: Perlite (1:1) following treatment with Captan (1.9 g I'1).