利用悬浮培养和培养基选择改善火炬松的体细胞胚胎发生和植株再生(英文)

三个基固型的火炬松成熟合子胚被培养在附加 8mg·L-12 ,4 D ,4mg·L-1BA ,4mg·L-1KT ,5 0 0mg·L-1水解酪蛋白和 5 0 0mg·L-1谷氨酰胺的愈伤组织诱导培养基上诱导愈伤组织 .来自于子叶、胚轴和胚根的愈伤组织在附加 1 6mg·L-12 ,4 D ,0 8mg·L-1BA和 0 8mg·L-1KT的愈伤组织增殖培养基上培养 9周后 ,可获得 16 9%的胚性愈伤组织 .通过建立胚性细胞悬浮系和研究ABA、PEG和活性炭对体细胞胚成熟的促进作用 ,优化的体细胞胚胎发生体系被建立 .71棵再生小苗被用于移栽试验 ,2 3棵小苗在田间移栽成活     

Selection of culture conditions for callus induction and proliferation by somatic embryogenesis of Pinus koraiensis

The induction and proliferation of embryogenic callus are key steps for large-scale propagation of somatic embryogenesis pathway and long-term preservation of coniferous germplasm.Callus can be induced from immature embryos of Korean pine(Pinus koraiensis Sieb.et Zucc.;Pinaceae) as explants,but there are problems,such as low proliferation efficiency,loss of embryogenicity,poor vigor;thus,best conditions for proliferation and culture of immature embryos of Korean pine are not yet clear.To solve the problems with somatic embryogenesis of Korean pine and determine the best culture conditions for callus induction and proliferation,we varied hormone concentration,subculture cycle of proliferation and other plant growth regulators combinations in media to induce callus formation by megagametophytes of three Korean pine families at different developmental stages,then analyzed the effects on embryogenic callus retention and cell proliferation using a quadratic regression orthogonal rotation design.The results showed that the family origin and collection date of explants significantly affected callus induction(induction rate reached1.67%).Embryogenic maintenance and callus proliferation were best on DCR medium supplemented with 0.25 mg L~(-1)6-benzyl adenine,1 mg L~(-1) naphthaleneacetic acid,30 g L~(-1)sucrose,500 mg L~(-1),L-glutamine,500 mg L~(-1) casein hydrolysis and 6.5 g L~(-1) agar.In addition,the combination of 2,4-dichlorophenoxyacetic acid+6-benzyl adenine also had a better proliferative effect on callus.The effects of different combinations of growth regulators on callus proliferation efficiency were significantly different.Transfer to new medium every 13-15 days not only maintained robust callus vigor,but also yielded a larger proliferation coefficient.The techniques and conditions for embryogenic callus induction and proliferation of Korean determined here will serve as a foundation for establishing a large-scale system for somatic embryogenesis and propagation of Korean pine.     

Efficient embryogenic callus induction and plant regeneration from embryonic axis explants inQuercus acutissima

Embryogenic callus ofQuercus acutissima was successfully induced from embryogenic cultures, and plants were regenerated from the callus. The development of the techniques involved will allow mass propagation and gene transformation in this species. Embryogenic cultures were formed from embryonic axis explants (i.e., embryos without cotyledons) excised from immature embryos, after culture on Murashige and Skoog (MS) medium containing indolebutyric acid and benzyladenine. Attempts to induce embryogenic cultures from cotyledon explants were unsuccessful. Embryogenic calli were induced at high frequency from embryogenic cultures on MS medium containing 2,4-dichlorophenoxyacetic acid. However, benzyladenine inhibited embryogenic callus formation. Somatic embryo development from embryogenic calli occurred on MS medium in all of the seven cell lines tested. Germination of somatic embryos was induced on half strength MS medium without plant growth regulators. Finally, acclimated plants growing in soil were obtained.     

Somatic embryogenesis of Pinus sylvestris

Embryogenic cultures (EC) of Scots pine (Pinus sylvestris L.) were initiated from immature embryos. Whole ovules were used as expiants. The responsive period for initiation began just after fertilization and remained throughout the development of first stages of early embryos. The main part of the embryogenic cultures were initiated by the time of cleavage polyembryony. Strong correlation was obtained between degree days and the responsive period. During subsequent years the experiments were repeated in Finland and Sweden. In all cases the responsive period for initiating embryogenic cultures was the same, about two weeks after fertilization.

In 1991–1993, a total of 138 clones of elite pine trees were tested for their ability to initiate embryogenic cultures. Of these, 33% were responsive under our experimental conditions. Based on about 300 ovules per clone the number of embryogenic lines induced by the responding clones varied from 0.2% to 9.0% of the expiants.

Several nutrient media were found to be suitable for initiation and proliferation of ECs. About half of the cell lines responded to abscisic acid by producing maturing embryos. The embryos reached full maturity in cultures of only a few cell lines. Some of the embryos that produced roots were planted in soil and transferred to a greenhouse.     

Initiation of somatic embryogenesis from immature zygotic embryos of oocarpa pine (Pinus oocarpa Schiede ex Schlectendal)

The focus of the current project was to establish somatic embryogenesis protocols for the tropical pine species Pinus oocarpa using immature zygotic embryos (ZEs) as explants. Somatic embryogenesis is best supported by mimicking natural seed-embryo developmental conditions, through a tissue culture medium formulation based on the mineral content of the seed nutritive tissue [megagametophyte (MG)]. A novel culture medium (P. oocarpa medium, PO) was tested in combination with different plant growth regulator (PGR) concentrations and compared with standard Pinus taeda media for the initiation of somatic embryogenesis from immature ZEs of P. oocarpa. Immature MGs containing immature ZEs of two mother trees were used with 12 and 8% extrusion rates for mother tree genotypes 3 and 5, respectively. In both mother trees the percentage capture was 2%. Multiplication of two captured cell lines (T5C2S01 and T5C1S12) was improved by lowering the concentrations of PGRs to 2.5 μM each 2,4-dichlorophenoxyacetic acid and abscisic acid (ABA) plus 1.0 μM each 6-benzylaminopurine and kinetin. Mature somatic embryos formed on 40 μM ABA, 6% (w/v) maltose, 12% (w/v) PEG 8000 and 0.6% (w/v) Phytagel. While PO medium appeared suboptimal for somatic embryo induction, it did exhibit potential for enhanced culture proliferation and subsequent improved maturation with cell line T5C2S01, where microscopic analysis revealed better embryo morphology on PO medium than on 1250 medium. However, this enhancement was not observed with cell line T5C1S12. Germination was preceded by partial desiccation for a period of 2-3 weeks before transferring the embryos to germination medium. Germination was observed after 7 days under low light, and apical primordia slowly expanded after transfer to ex vitro conditions. To our knowledge, this is the first report on the production of somatic seedlings in P. oocarpa.     

火炬松体细胞胚胎发生和干化体细胞的氧化物酶活性(英文)

培养于附加2,4-D、BA和KT的愈伤组织诱导培养基上的火炬松成熟合子胚在培养3-9周后形成白色、半透明、有光泽的粘性愈伤组织。这类愈伤组织形成于成熟合子胚的子叶,但当用NAA或者IBA代替愈伤组织诱导培养基中的2,4-D时,它的诱导频率明显降低。这种粘性愈伤组织在分化培养基上形成体细胞胚。体细胞胚经过去50μm ABA和8.5%PEG600处理后成为耐干化胚。扫描电镜观察表明,萌发处理36小时后,耐干化胚恢复到干化处理之前的状态且大小和形态正常,而不耐干化胚不能恢复到干化处理之前的状态且表面撕裂。过氧化物酶活性的分析结果表明,耐干化胚有更高的过氧化物酶活性。耐干化胚的高过氧化物酶活性可能与催化H2O2的分解和保护体细胞胚免受氧化的伤害有关。     

Improving plantlet yield in Pinus pinaster somatic embryogenesis

Abstract

Somatic embryogenesis is expected to play a significant role in the future forest tree improvement programmes. The main bottleneck of this technique is still the progression from immature embryogenic cultures to mature cotyledonary embryos able to develop properly into well-growing plants. In this work, we present an improved protocol focused on increasing the maturation and conversion rate of Pinus pinaster Ait. embryogenic cultures. Results showed that the optimisation of the nutrient composition in the maturation medium increased the number of mature embryos by 25% (187.8 embryos per gram of fresh mass in average compared to 144.5 embryos in regular medium). It was also shown that 12-month cryostorage did not reduce viability or embryogenic ability of maritime pine cultures. A further increase in the yield of the protocol could be obtained by using benzyladenine in the conversion medium, promoting the bud-break of axillary buds that yielded 5.7 shoots in average per somatic embryo. Rooting of axillary shoots reached 84.3%. This methodology offers an alternative to overcome some problems associated with low somatic embryo production since the plantlet yield could be increased fivefolds.     

刺槐未成熟合子胚的体细胞胚胎发生和植株再生

以刺槐不同胚龄的未成熟合子胚为外植体,采用混合正交试验设计,研究幼胚胚龄和不同外源激素种类及质量浓度对刺槐胚性愈伤组织的诱导和体细胞胚分化、萌发的影响.结果表明:开花后8周(55天左右)是胚性愈伤组织和体胚诱导的最佳外植体取材时期;MS+2,4-D 5.0 mg·L-1 +BA0.5 mg·L-1是诱导胚性愈伤组织的最佳培养基,出愈率最高为95.42％±0.02％;MS +NAA0.5 mg·L-1 +BA0.5 mg·L-1+谷氨酰胺250 mg·L-1+水解酪蛋白500 mg·L-1是体细胞胚诱导和分化的最佳培养基,直接体细胞胚发生率最高为92.40％±0.12％,通过愈伤组织诱导体细胞胚发生的频率最高为90.73％ ±0.49％.一旦形成球形胚,将培养物转接到不含任何生长调节剂的MS培养基上,体细胞胚经成熟萌发可进一步形成完整小植株.     

Plantlet regeneration through somatic embryogenesis in Nordmann's fir (Abies nordmanniana)

I studied the influence of various combinations of auxin and cytokinin concentrations, and the increased content of zinc and enzymatic casein hydrolizate in SH medium on initiation and proliferation of embryogenic callus of Abies nordmanniana(Steven) Spach. Additionally, the effect of ABA, PEG-4000 and different wavelengths on the maturation of somatic embryos was tested.The use of optimum composition of modified SH medium with BA, KIN and 2.4-D while simultaneously ensuring appropriate external conditions resulted in 15.5 % embryogenesis. Finally, satisfactory results of micropropagation of A. nordmanniana by somatic embryogenesis were obtained providing seven lines of embryogenic callus with high proliferation capacity. Those lines gave properly developed seedlings in white LED light with a wavelength of 400-700 nm, preceded by eight-week vernalization treatment of the callus. This paper may provide a protocol by which all stages of somatic embryogenesis of A. nordmanniana can be carried out, including the preceding 24-h seed disinfection with Na OCl and PVP, which resulted in 100 % frequency of uninfected zygotic embryos that were capable of starting embryogenesis.     

In vitro somatic embryogenesis in callus cultures of Azadirachta indica A. Juss.—a multipurpose tree

Plant regeneration via somatic embryogenesis was achieved in embryogenic callus cultures derived from immature zygotic embryos 40 days after anthesis of Azadirachta indica A. Juss. on semisolid basal Murashige and Skoog (MS) salts and vitamins supplemented with 1.11 µM 6-benzylaminopurine (BA) and 4.52–6.78 µM 2,4-dichlorophenoxyacetic acid (2,4-D). The globular-stage embryos were induced when the callus was transferred to medium with 1.11 µM BA and 0.45 µM 2,4-D. The highest average number of somatic embryos per 200 mg of callus was 152.8 after 8 weeks of culture on the medium. Maturation and germination of the somatic embryos were achieved on half-strength MS salts and vitamins supplemented 0.38–0.94 µM abscisic acid (ABA) and 2% (w/v) sucrose. The maximum percentage (64.2%) of germination was obtained with 0.94 µM ABA within 2 weeks of culture. Somatic embryo-derived plantlets were acclimatized in a greenhouse and subsequently showed normal growth. This efficient protocol will be helpful for propagating elite clones on a mass scale and will also be useful for genetic transformation study.     

Somatic embryogenesis inCephalotaxus harringtonia embryo-megagametophyte co-culture

Somatic embryogenesis was initiated fromCephalotaxus harringtonia (Forbes) K. Koch embryo culture. Explants consisted of embryo and megagametophyte halves both cut longitudinally. They were removed aseptically from mature seeds and grown together on a solid Murashige and Skoog modified medium supplemented with 5 mg·l ⁻¹ 2,4-dichlorophenoxyacetic acid. Embryogenic cultures started from callus after three or more months on the primary medium. The embryogenic callus originated from the suspensor region of the embryo. All chromosome counts made in the cells of the embryonic structures demonstrated a diploid stage, which suggest that they originated from zygotic embryo tissue. The early stages of somatic embryogenic development were achieved,i.e., formation of small clusters consisting of an embryonal region made up of isodiametric meristematic cells. A more advanced stage was reached in some cultures in which the distal embryonal end of the embryo appeared smooth and opaque. The ultrastructural characteristics of the embryos, the two types of embryo cells, embryonal and suspensor cells, as well as their contents were similar to those already reported in the case of somatic embryogenesis of other conifers.     

Organogenesis and embryogenesis in mature zygotic embryos of Picea sitchensis

Differentiation of adventitious buds and somatic embryos from mature zygotic embryos of Picea sitchensis (Bong.) Carr. is described. Adventitious buds were formed on embryos pulse-treated with 250 microM benzyladenine for 2 h and cultured on medium lacking growth regulators. Buds were initiated at different frequencies and sites depending on when the BA-pulsed embryos were transferred to fresh culture medium. Embryogenic callus was formed when the zygotic embryos were cultured on medium containing 10 microM 2,4-dichlorophenoxyacetic acid and 5 microM benzyladenine. Although 50% of the embryos gave rise to embryogenic callus, only 20% of the callus continued to proliferate after subculture. Proliferation of new somatic embryos occurred from both the embryonic region and the suspensor region on previously formed somatic embryos. The pattern for development of adventitious buds and somatic embryos in Picea sitchensis is compared to that in Picea abies under similar culture conditions.     

水曲柳体细胞胚与合子胚发生的细胞学研究

水曲柳(Fraxinus mandshurica)属木犀科(Oleaceae)白蜡树属,是我国东北重要珍贵硬阔树种之一,主要分布于小兴安岭、长白山、辽宁东部山地等地区, 以材质优良而著称.由于长期不合理的采伐利用,目前可利用的资源急剧减少,已被列为国家三级保护植物(傅立国,1992).进行水曲柳体细胞胚胎发生的研究,在资源保护、树种快繁和基因工程育种上有其重要的现实意义.     

Seedling shoot,needle and bud development in three provenances of Pinus sylvestris and Pinus contorta cultivated in northern Sweden

The patterns of current‐year shoot, needle and terminal bud elongation in seedlings of three Scots pine (Pinus sylvestris L.) and three lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) provenances were compared during the third and fourth growing seasons after planting. Lodgepole pine produced longer shoots and buds than did Scots pine, mainly because lodgepole pine formed more stem units and elongated at a faster rate. Stem unit length and the duration of shoot and bud elongation differed relatively little between species and provenances. Lammas or polycyclic growth occurred in some lodgepole pine provenances, but not in any Scots pine provenance, and was associated with enhanced shoot elongation. Needle elongation commenced earlier, proceeded at a faster rate, and was greater in lodgepole pine than in Scots pine, but ceased about the same time in all species and provenances. The heat sum required to attain 50% of final length was lower for shoots and needles in lodgepole pine than in Scots pine, and for shoots in northern provenances than in southern ones. Mitotic activity in the apical meristem of the terminal bud, which occurred less than one week after the seedlings were free from snow, started and ceased about the same time in each species, but was higher in lodgepole pine than in Scots pine early in the shoot elongation period.     

Somatic embryogenesis from cell suspension cultures of aspen clone

Suspension cultures initiated from callus derived from petiole explants of aspen hybrid (Populus tremuloides × P. tremula) produced somatic embryos. Callus was induced on a MS medium supplemented with 5 mg·L–1 2,4-D and 0.05 mg·L–1 zeatin under light conditions. Embryogenic calli were obtained when a subsequent subculture of calli was suspended in the same basal me-dium with 10 mg·L–1 2,4-D. The highest number of globular embryos were induced from embryogenic calli by cell suspension cul-ture in a MS liquid medium supplemented with 10 mg·L–1 2,4-D. Genotype and 2,4-D concentration were vital to the induction of embryogenic calli producing competent cells. Embryogenic calli for each genotype were heterogeneous. Green calli with gel-like consistency could yield more competent cells than light yellow embryogenic calli. However, some globular embryos broke into slices and some developed abnormally after one month of culture under the same or other hormonal conditions.     

Somatic embryogenesis from vegetative shoot apices of mature trees of Pinus patula

Embryogenic cultures were initiated and established from apical shoots of mature trees of three genotypes of Pinus patula Scheide et Deppe. Factors affecting initiation, including cold pretreatment, basal medium composition, growth regulators and gelling agent concentration, and the effect of partial desiccation on somatic embryo maturation were investigated. Cold pretreatment of thick sections (0.5-1.0 mm) of apical shoots at 2 degrees C for 3 days on 0.3% activated charcoal induced white mucilaginous embryogenic callus on initiation medium. Subculture of this embryogenic callus on maintenance medium resulted in the formation of embryonal suspensor masses with proembryos. Partial desiccation (12-90 h) of embryogenic tissue at the proembryo stage of development, prior to transfer to maturation medium containing 9 g l(-1) Gellan gum, enhanced somatic embryo maturation and germinability. The frequency of maturation increased from 5.3 to 16.5% after 12 h of desiccation and from 16.5 to 73.8% after 24 h of desiccation, but longer periods of desiccation were ineffective.     

火炬松胚性愈伤组织诱导和植株再生的研究

火炬松胚性愈伤组织诱导和植株再生的研究唐巍欧阳藩（中国科学院化工冶金研究所生化工程国家重点实验室北京１０００８０）郭仲琛（中国科学院植物研究所北京１０００９３关键词火炬松,体细胞胚胎发生,植株再生本文于１９９６年１０月２８日收到。国家“８６３”资...     

Pine somatic embryogenesis: analyses of seed tissue and medium to improve protocol development

The shift from vegetative to embryogenic growth requires tissue to enter a radically different program of development and can be studied in vitro through the development of somatic embryos. From an applied perspective somatic embryogenesis (SE) is expected to play an important role in increasing productivity, sustainability, and uniformity of future forests. For commercial use, SE technology must work with a variety of genetically diverse trees. Since the first reports of SE in Picea abies and Larix decidua in 1985, many different coniferous species have shown the ability to produce embryogenic tissue. However, initiation frequency is often low, many desired seed sources are recalcitrant, and culture survival is often poor, raising costs of somatic seedlings produced from successful genotypes. A number of tools are now available to improve embryogenic tissue initiation and somatic embryo development in vitro that have resulted from analytical studies of seed tissues, the seed environment and gene expression in megagametophyte, zygotic embryos and somatic embryos. Benefits have occurred from medium supplementation with hormones, plant growth regulators, hormone inhibitors and polyamines. Somatic embryo growth has been enhanced with medium supplementation of nutritional components including specific sugar types, vitamins, organic acids, and redox potential modifiers. Control of environmental factors including, water potential, pH, adsorption of medium components by activated carbon and liquid versus gelled medium have also led to SE protocol improvements. The use of analytical studies to duplicate the seed environment in vitro is improving protocol development resulting in increased initiation, improved yields and higher-quality somatic embryos.     

Effect of parent genotype on somatic embryogenesis in Scots pine (Pinus sylvestris)

Controlled crosses of seven Scots pine (Pinus sylvestris L.) trees produced 49 families that included both reciprocals and selfings. Embryogenic cultures were initiated from immature megagametophytes and after 6 months in maintenance culture, mature somatic embryos were produced from the surviving 166 lines. The effect of parent genotypes on the cultures was evaluated at initiation of the tissue culture period, after 6 months in maintenance culture and at embryo maturation. The effect of the maternal parent was most pronounced at culture initiation. After 6 months in tissue culture, the maternal effect had decreased and the effects of both parents were significant. By the somatic embryo maturation stage, the maternal effect was still considerable but the paternal effect was no longer detectable. There was little correlation between the ranking of mothers and fathers, indicating that the maternal effect was caused by factors other than the paternal effect. No mother x father interaction was found, indicating that mothers successful at initiation and after 6 months in tissue culture, pollinated by any of the successful fathers, produced somatic lines and mature somatic embryos.     

Somatic embryogenesis, micropropagation and plant regeneration of "Early Mature" walnut trees (Juglans regia) that flower in vitro

Some walnut trees (Juglans regia L.) originating from central Asia display an early flowering phenotype. These "Early Mature" (EM) trees may produce flowers within months of germination. Secondary flowering waves are also observed within a growing season. Inflorescences may carry male, female and hermaphrodite flowers. Progeny obtained from selected EM trees were cultured in vitro to initiate clonal propagation of these genotypes. Embryogenic lines were established through the culture of immature zygotic embryos. Microshoot lines were obtained from germinated somatic or zygotic embryos. Plants showing EM phenotypes were recovered through direct conversion of somatic embryos or adventitious rooting of microcuttings. During the in vitro propagation phase, flower buds were observed on microshoots after three to six subcultures. Histological analysis showed that most of these flowers were hermaphrodite. In vitro apical buds were used to clone the walnut orthologous cDNAs of the AGAMOUS and APETALA 3 MADS-box genes. Northern blots revealed a preferential expression of both of these homeotic genes in flowers. The results highlight the usefulness of EM lines to study the genetic cues controlling flowering and sexual maturity in woody perennials.