Callus Culture of Sainfoin (Onobrychis viciifolia) and Plant Regeneration through Somatic Embryogenesis

Callus of sainfoin (Onobrychis viciifolia Scop.) was initiatedfrom stem and root explants which were obtained from seedlingsgrowing in vitro, on Linsmaier Skoog (LS) medium supplementedwith 1 mg l^–1 2, 4-D and 1 mg l^–1 BA or only 1 mgl^–1 BA, and the Vacin and Went medium without hormones.Somatic embryos were formed on LS medium containing 1 m l^–1BA. Embryos developed into complete plants on filter paper saturatedwith hormone-free LS medium. Onobrychis viciifolia, somatic embryogenesis, callus culture, plant regeneration     

Somatic Embryogenesis and Plant Regeneration from Protoplasts of Cowpea (Vigna sinensis)

Immature cotyledons of cowpea (Vigna sinensis Endlo) were used for protoplast isolation. Enzyme solution for protoplast isolation contained 40% cellulase Onozuka R-10,0.30% Macerozyme R-10 and 2% hemicellulase. The purified protoplasts were cultured in Bs,MS or KM8p liquid medium in dark (25℃) at a density of 1 × 105–5 × 105/ml. The protoplasts started cell division in 3–5 days . Sustained cell divisions resulted ill formation of cell clusters and small calli,with cell division frequency reaching 23%–28% in MS medium . Calli of 2 mm in size were transferred onto MSB (MS salts+B5 vitamins) medium with 2 mg/L 2,4-D, 0. 5mg /L BA forfurther growth. Embryogenic calli appeared on this medium. After passage to fresh medium with the same composition, the embryogenic calli were transferred into MSB liquid medium to establish suspension culture. When the suspended calli were transferred back onto MSB agar medium with 0. 1 mg /L IAA, 0.5mg/L KT, 5% mannitol (cultured in light,2000 lx,12h/d), a lot of adventitious roots formed in 7–10 days, and then somatic embryos formed from the protoplast derived calli. But only a few embryoids developed further into the cotyledonary stage ,and the others died at globular, heart-shaped, or torpeto stage . Finally, some cotyledonary embryoids germinated and developed into plantlets or shoots with leaves.     

Somatic Embryogenesis and Plant Regeneration from Papaya Suspension Cultures

Compact embryogenetic calli were obtained from explants on P3 medium after 4 weeks of culture and high-frequency somatic embryogenesis occurred after these calli were transferred into suspension culture. Experimental data showed that low level (0.2%W/V) of activated charcoal had beneficial effects on somatic embryogenesis. Abundant calli on P4 medium however, showed no embryogenesis. On the other hand, callus induction and somatic embryogenesis varied with different rarities of exptants. The efficiency of somatic embryogenesis was much higher, if roots were used as explants, whereas stems were more suitable for callus formation Mature somatic embryos with cotyledons were cultured on MS medium containing different plant hormones. The optimum medium for germination and growth of entire plantlet was Mso medium. The somatic embryos on MS2, MS and MS3 media germinated rapidly, but formed excessive callus from the surface of germinating embryos.     

Somatic Embryogenesis and Plant Regeneration in Pigeonpea

Somatic embryogenesis in pigeonpea [Cajanus cajan (L.) Millsp.] has been achieved using cotyledon segments of mature seeds as explants. A large number of globular somatic embryos were induced directly from cotyledons of genotypes T-15-15, GAUT-82-90 and GAUT-82-99 when cultured on EC6 basal medium supplemented with 2.22, 4.44, 13.32 or 22.2 M N⁶-benzylaminopurine (BAP) and 0.45, 1.36, 2.27, 4.54 and 13.62 M thidiazuron. Somatic embryos developed into cotyledonary stage when the globular embryos were transferred to Murashige and Skoog's (MS) basal medium containing 2.89 – 14.43 M gibberellic acid. Maturation of somatic embryos was achieved on half strength MS medium with 0.38 M abscisic acid. The mature somatic embryos were germinated on MS medium supplemented with 0.44 M BAP and the plantlets were hardened and transferred to soil.     

木薯体细胞胚胎发生及植株再生研究

对木薯体细胞胚胎发生的影响因素进行了优化研究。结果表明,基因型对木薯体细胞胚胎发生影响很大,在供试的六个品种中,“华南 8 号”的体细胞胚胎发生率和产胚量最高,分别为 65% 和19个;侧芽茎尖为最佳外植体,体细胞胚胎发生的最佳培养基为MS +0.5mg/L CuSO4 + 4 mg/L 2,4-D。同时,对木薯体细胞胚再生成完整植株的主要影响因素作了分析,建立了一个高效的植株再生体系。     

三叶半夏悬浮培养下的体细胞胚胎发生及植株再生

用三叶半夏幼嫩叶片诱导产生的胚性愈伤组织建立了胚性细胞悬浮系,研究了悬浮培养下体细胞胚胎的发生及植株的再生。结果表明,胚性悬浮细胞在附加1．0mg／L2,4-D、0．2 mg／LBA和300mg／L LH的MS液体培养基中产生大量的球形胚,转入液体分化培养基(MS 0．1 mg／LNAA 0．2 mg／L BA 300 mg／L LH)中进一步发育成心形胚、鱼雷形胚和子叶形胚。收集成熟胚转移到MS固体分化培养基上培养获得了再生植株。另外还观察到某些成熟胚上产生了许多次生胚。     

Somatic Embryogenesis and Plant Regeneration from Suspension Cultures of Pearl Millet (Pennisetum americanum)

Immature embryos of Pennisetum americanum (pearl millet), culturedin the presence of 2,4-dichlorophenoxy acetic acid (2,4-D) produceda pale-yellow and compact callus tissue by proliferation ofthe scutellum. Teased pieces of the compact callus were placedin a liquid medium on a gyrotory shaker to establish suspensioncultures. The cultures were composed of large, elongated andhigly vacuolated cells, and a population of richly cytoplasmiccells. The latter, here termed embryogenic cells, containednumerous plastids with starch, and occurred in tight groupsof four or more cells, and occasionally as single cells. Structuresresembling various stages of embryogenic development were foundin the suspension cultures. When the cultures were plated ina 2,4-D-free agar medium containing abscisic acid, embryoidswith the typical organization of cereal embryos were produced.The embryoids ‘germinated’ in vitro to give riseto plantlets, which were successfully transferred to soil. Theregenerated plants showed the normal diploid chromosome numberof 14. Embryoids apparently arose from single embryogenic cells,either directly or after the formation of a proembryonal massof cells. embryogenesis, pearl millet, Pennisetum americanum, regeneration, suspension culture     

盐肤木体细胞胚胎发生及植株再生

以盐肤木(Rhus chinensis Mill.)幼胚为外植体,研究不同植物生长调节剂组合对其愈伤组织诱导及体细胞胚胎发生的影响,以建立盐肤木体细胞胚胎发生及植株再生体系。结果表明,最适愈伤组织诱导培养基为MS+6-BA 0.2 mg/L+2,4-D 1.0 mg/L,诱导率为84.57%,诱导出的初代愈伤组织白色或淡黄色,质地疏松,表面光滑,为非胚性愈伤。初代愈伤组织转移到1/2 MS+6-BA 2 mg/L+NAA 0.5 mg/L培养基上培养1个月后,长出淡黄色质地紧密的胚性愈伤组织,诱导率高达100%,在此培养基上胚性愈伤组织增殖倍数为854.73%。所获得的胚性愈伤组织转接到1/2 MS+6-BA 2 mg/L+NAA 0.5 mg/L+蔗糖4%的培养基上培养1个月后可诱导体细胞胚胎发生,诱导率可达32.67%。诱导得到的体细胞胚胎经历球形胚、心形胚、鱼雷胚、子叶胚进一步分化发育成苗。无菌苗炼苗后栽种到泥炭土∶蛭石∶珍珠岩为2∶1∶1的生长基质上,能100%稳定成活。经过细胞学观察分析,体细胞胚的发育与合子胚相似。     

陆地棉体细胞胚胎发生与植株再生

利用陆地棉品种下胚轴为外植体进行体外培养研究。激素和品种是影响愈伤诱导和胚胎发生的主要因素。去除激素后胚性愈伤在固体培养基上只能形成少量的成熟胚。悬浮培养是获得大量成熟胚的中间步骤。悬培两周后,悬培物转到固体培养基上促进胚状体成熟,30—60目之间的悬培物比大于30目的悬培物易形成成熟胚。KT 0.1ppm、Zea 0.1ppm分别有效地促进了胚状体成熟。活性碳250mg/L、NAA 0.1ppm、IBA 0.1ppm和IAA 0.1ppm能使胚状体萌发并健壮生长。目前已得到100多株幼苗,大苗已达八片真叶。     

Somatic Embryogenesis and Plant Regeneration from Leaf Callus of Hordeum vulgare

Explants obtained from the basal portion of leaves of Hordeumvulgare (cv. Karan 92) gave rise to callus when cultured onMurashige and Skoog (MS) basal medium supplemented with 2, 4-dichlorophenoxyaceticacid (2, 4-D). Initially, the callus was friable, shiny-whiteand watery but subsequently some compact, nodular callus appeared.The latter were cultured on MS medium containing 0.05 mg l^–12, 4-D and 0.1 mg l^–1 N6-furfurylaminopurine (kinetin),when plantlets were generated. Histological studies showed thatplantlet regeneration occurred by the formation of somatic embryos.The regenerated plants had the normal diploid chromosome number(2n = 14). Hordeum vulgare, barley, somatic embryogenesis, tissue culture, plant regeneration     

Somatic Embryogenesis and Plant Regeneration in Kinnow Mandarin

Somatic embryogenesis and plant regeneration from stem explants of kinnow mandarin, a hybrid of king and willow mandarins, are reported. It is an economically important cash crop of India with great deal of production and export. This is for the first time that callus induction and internodal regeneration has been successfully achieved in this citrus cultivar. Callus was induced from nodal segment (1-2 cm) of kinnow mandarin on Murashige and Skoog (MS) medium supplemented with α-naphthaleneacetic acid (NAA) and benzyl amino purine (BAP). Cotyledonary stage somatic embryos with regenerated shoots were induced on BAPenriched medium. Roots developed when regenerated shoots were excised and cultured on half strength MS medium supplemented with NAA only.     

Plant Regeneration Through Somatic Embryogenesis in Taxus wallichiana

We describe an efficient process for regeneration of Taxus wallichiana (Zucc) plants from callus cultures derived from zygotic embryos. Zygotic embryos cultured on half strength Lloyd and McCown’s basal medium supplemented with SH vitamin (1/2 WPMSH), 0.5 mg I^?1 6-benzyladenine (BA) and 1.0–2.0 mg I^?1 á-Napthaleneacetic acid (NAA) produced compact yellow (CY) callus after 4 weeks of culture. The 8-week-old CY call! (lines CY-A and CY-B) were initially slow growing but proliferated on transfer to WPM basal medium supplemented with 8.0 mg I^?1 2,4-D, 0.1–0.9 mg^?1 NAA and 0.3–1.0 mg^?1 BA after 4 weeks. Four morphologically distinct calli lines were obtained, of which only two call! lines, CY-B-FW and CY-B-FY were embryogenic. The 12-week-old callus line CY-B-FW developed globular somatic embryos on transfer to secondary medium after 8 weeks and matured in maturation medium after 4 weeks. Only 10% of the mature somatic embryos regenerated into complete plantlets after 4 weeks on conversion medium. Although the frequency of conversion was low, complete regenerated plantlets via somatic embryogenesis were obtained after 7–8 months of initiation of culture. Taxane analysis showed that the paclitaxel accumulation was higher in embryogenic callus than in non-embryogenic callus.     

百合体细胞胚胎发生和植株再生

以切花百合(Lilium)品种‘黄天霸’(‘Manissa’)花器官为外植体诱导体细胞胚胎发生与植株再生。结果表明,不同花器官、不同激素配比对愈伤组织形成均具有显著影响。花丝为最佳外植体,激素对愈伤组织诱导的影响效应为NAA>6-BA>2,4-D,最适培养基为MS+1.0 mg.L-1NAA+0.2 mg.L-16-BA;激素诱导体细胞胚胎发生的影响效应为2,4-D>KT>6-BA,最佳培养基配方为MS+1.0 mg.L-12,4-D+0.2 mg.L-1KT+1.0 mg.L-16-BA;MS培养基添加IBA可促进体细胞胚萌发成苗,体细胞胚芽成苗的最佳培养基为MS+0.2 mg.L-16-BA+1.0 mg.L-1IBA。     

枸杞花药愈伤组织悬浮培养条件下胚状体发生与植株再生

采用枸杞花药进行离体培养,建立细胞系,诱导植株再生,结果在含不同激素的4种培养基上都诱导出了愈伤组织,诱导率为17%～169%。愈伤组织在MS 2,4D05mg/L的固体培养基上,经2～3次培养后,获颗粒状胚性愈伤组织,颗粒状胚性愈伤组织转入含相同成分的液体培养基中进行振荡培养,24h后获得大量单细胞。单细胞液经过多次继代培养,建立起稳定的悬浮系。悬浮细胞在液体培养基中培养8～10d可获得含有大量胚状体的愈伤组织块,收集悬浮培养物转移到MS 6BA02mg/L的固体培养基上,胚状体能够萌发形成大量绿色小芽,小芽转入生根培养基(MS NAA02mg/L)中20d后得到完整植株。植株根尖细胞经细胞学鉴定为单倍体。     

Somatic Embryogenesis and Plant Regeneration from Cultured Leaf Explants of Zea mays

Young leaf segments of Zea mays L. seedlings were cultured onMurashige and Skoog's basal nutrient medium supplemented with2 mg l^–1 2, 4-D and sub-cultured on medium containing8 mg l^–1 2,4-D. Two types of callus tissues appeared—embryogenicand non-embryogenic. The embryogenic callus tissue producednumerous somatic embryos which on transfer to media containinglow amounts of 2,4-D or ABA produced plantlets. Callus tissuesexhibited embryogenic potential for more than 1 year. Zea mays L. cv. Ageti-76, Zea mays L. cv. N-L-D-Comp., maize, leaf, callus, somatic embryogenesis, regeneration     

百合未授粉子房离体培养胚胎形成及植株再生

未受精子房离体培养是诱导雌核产生单倍体的技术之一。以1个野生种和3个杂种系共7个百合(Lilium)基因型为实验材料, 探讨了基础培养基、花蕾取样时期和外源激素等因素对百合未授粉子房离体培养胚胎形成的影响。结果表明, CBM、MS和BDS三种基础培养基均可诱导百合未授粉子房胚胎形成, 但以BDS培养基诱导效果最佳; 开花前1天的花蕾较适于百合未授粉子房离体培养; 2 mg·L^-1 2,4-D + 2 mg·L^-1 6-BA和2 mg·L^-1 2,4-D + 2 mg·L^-1 KT两种外源激素配方均适用于百合未授粉子房离体培养诱导胚胎形成。在培养过程中, 大多数胚性胚珠中只含有1个胚胎, 位于珠孔端、合子端或极核处, 少数胚性胚珠中含有双胚胎。通过百合未授粉子房离体培养, 从5个基因型材料中共获得146株再生植株。采用根尖染色体计数法对其中的62株进行了倍性测定, 其中43株与母体植株染色体倍性不同。     

Response of Java citronella (Cymbopogon winterianus Jowitt) to toxic heavy metal cadmium.

Cadmium at 200 mg kg-1 soil and above concentrations was fatal as growth was inhibited ultimately leading to death of Java citronella (Cymbopogon winterianus Jowitt.). The surviving plants at 50 and 100 mg kg-1 treatments also exhibited pronounced retardation of growth and biomass yield. There was considerable reduction in the level of essential oil in herbage and oil quality deteriorated. Cadmium accumulation profile showed that highest accumulation was in root, followed by stem, leaf sheath and leaf. Very high accumulation in root for higher doses appeared to be the reason for fatality.     

Benzyladenine Induced Somatic Embryogenesis and Plant Regeneration of Leptadenia reticulata

Plant regeneration through indirect somatic embryogenesis was attempted from leaf, internode, node and shoot-tip derived callus of Leptadenia reticulata. Somatic embryos at the highest frequency was induced on Murashige and Skoog (MS) medium supplemented with 8.87 μM benzyladenine (BA) and 2.46 μM indole-3-butyric acid (IBA). From different explants, only shoot-tip and node explant derived calli induced somatic embryos. Transfer of the embryogenic callus to suspension cultures of the same concentration of growth regulators facilitated the development of embryos. Suspension cultures with reduced concentration of BA (2.22 μM) either alone or in combination with 0.49 μM IBA fostered maturation of embryos. Half-strength MS solid medium with 1.44 μM GA₃ and BA (0.22 or 0.44 μM) facilitated conversion of embryos into plantlets at higher rate compared to that on with BA alone. About 77 plantlets were recovered from 10 mg callus. Plantlets transferred to small cups and subsequently to field survived in 80 %. All the plantlets established in the field exhibited morphological characters similar to that of the mother plant. This revised version was published online in July 2006 with corrections to the Cover Date.