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1.
Zygotic embryos at different developmental stages were tested for their potential in the initiation of embryogenic suspensor
mass (ESM) lines using immature seeds of Pinus rigida × P. taeda. The highest frequency (1.1%) of ESM was obtained with explants from cones collected on July 1. All excised embryos of the
July 1 collection were at the early proembryo stage. Two different culture media were compared. Forty-eight ESM lines were
initiated on Pinus taeda basal medium (P6) (0.97%) with 13.5 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 4.4 μM benzyladenine (BA). However, only
four ESM were obtained on a modified Murashige and Skoog medium (MSG; 0.55%). Most of the ESM arose from the seeds that were
at the stages ranging from late cleavage polyembryony to the early staged proembryo. Out of 52 lines (0.46%) that were produced
from 11,388 explants, only two viable lines (0.018%) (PRT11 and PRT28) survived. As for somatic embryo maturation, the highest
number (224/g−1 FW) of matured cotyledonary somatic embryos (line PRT 28) was obtained on a medium containing 100 μM abscisic acid (ABA),
0.2 M maltose, and 1.2% gellan gum. For germination of the somatic embryos, the cotyledonary somatic embryos derived from
maturation medium were transferred on half-strength Litvay medium (LM) plus 0.4% gellan gum. The germination rates were high
(71.4–96.3%) regardless of the concentrations of either ABA or gellan gum in the maturation medium. Approximately 500 somatic
plants were recovered from the germination medium and transferred to the green house; finally most of them were transplanted
successfully to the experimental field. 相似文献
2.
A somatic embryogenic system was developed and plants regenerated in mimosa (Albizia julibrissin Durazz). Development of somatic
embryos in the species has not previously been reported. Immature seeds, embryo cotyledons and embryo axes (cotyledons removed)
at defined developmental stages were placed on induction media with different concentrations of 2,4-D. Two distinct embryogenic
responses occurred: either proembryo masses or cotyledonary-stage embryos. Twenty five percent of all embryo axes cultured
on basal medium produced cotyledonary somatic embryos. Six percent of in ovulo immature seed explants generated proembryo
masses. These masses proliferated in liquid culture in the dark. Proembryos developed further when transferred to a growth-regulator-free
semisolid medium in the light. Somatic embryos derived from either proembryo suspensions or cotyledonary embryo cultures on
semisolid medium germinated to form plants that continued to grow vigorously following transfer to soil.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
3.
A highly reproducible system for efficient plant regeneration from protoplast via somatic embryogenesis was developed in cotton (Gossypium hirsutum L.) cultivar ZDM-3. Embryogenic callus, somatic embryos and suspension culture cells were used as explants. Callus-forming
frequency (82.86 %) was obtained in protoplast cultures from suspension culture cells in KM8P medium with 0.45 μM 2,4-dichlorophenoxyacetic acid (2,4-D), 0.93 μM kinetin (KIN), 1.5 % glucose and 1.5 % maltose. Protocolonies
formed in two months with plating efficiency of 14 %. However, the callus-forming efficiencies from other two explants were
low. The calli from protoplast culture were transferred to somatic embryo induction medium and 12.7 % of normal plantlets
were obtained on medium contained 3 % maltose or 1 % of each sucrose + maltose + glucose, 2.46 μM indole-3-butyric acid (IBA)
and 0.93 μM KIN. Over 100 plantlets were obtained from protoplasts derived from three explants. The regenerated plants were
transferred to the soil and the highest survival rate (95 %) was observed in transplanting via a new method. 相似文献
4.
M. Muruganantham S. Amutha A. Ganapathi 《In vitro cellular & developmental biology. Plant》2010,46(1):34-40
The regeneration of plants via somatic embryogenesis liquid shake culture of embryogenic calluses was achieved in Vigna mungo (L.) Hepper (blackgram). The production of embryogenic callus was induced by seeding primary leaf explants of V. mungo onto Murashige and Skoog (MS) (Physiol Plant 15:473–497, 1962) medium supplemented (optimally) with 1.5 mg/l 2,4-dichloro-phenoxyacetic acid. The embryogenic callus was then transferred
to liquid MS medium supplemented (optimally) with 0.25 mg/l 2,4-dichloro-phenoxyacetic acid. Globular, heart-shaped, and torpedo-shaped
embryos developed in liquid culture. The optimal carbohydrate source for production of somatic embryos was 3% sucrose (compared
to glucose, fructose, and maltose). l-Glutamine (20 mg/l) stimulated the production of all somatic embryo stages significantly. Torpedo-shaped embryos were transferred
to MS (Physiol Plant 15:473–497, 1962) liquid medium containing 0.5 mg/l abscisic acid to induce the maturation of cotyledonary-stage embryos. Cotyledonary-stage
embryos were transferred to 1/2-MS semi-solid basal medium for embryo conversion. Approximately 1–1.5% of the embryos developed
into plants. 相似文献
5.
Embryogenesis and plant regeneration of hot pepper (<Emphasis Type="Italic">Capsicum annuum</Emphasis> L.) through isolated microspore culture 总被引:1,自引:0,他引:1
We report high frequencies of embryo production and plant regeneration through isolated microspore culture of hot pepper (Capsicum annuum L.). Microspores cultured in modified NLN medium (NLNS) divided and developed to embryos. Globular and heart-shaped embryos
were observed from 3 weeks after the beginning of culture, and many embryos reached the cotyledonary stage after 4 weeks of
culture. These cotyledonary embryos developed to plantlets after transfer to solid B5 basal medium. We also optimized conditions
for embryo production by varying the pretreatment media, the carbon sources, and culture densities. Heat shock treatment in
sucrose-starvation medium was more effective than in B5 medium. Direct comparisons of sucrose and maltose as carbon sources
clearly demonstrated the superiority of sucrose compared to maltose, with the highest frequency of embryo production being
obtained in 9% (w/v) sucrose. Microspore plating density was critical for efficient embryonic induction and development, with
an optimal plating density of 8 × 104–10 × 104/ml. Under our optimized culture conditions, we obtained over 54 embryos, and an average of 5.5 cotyledonary embryos when
10 × 104 microspores were grown on an individual plate. 相似文献
6.
Xin Y. Li Feng H. Huang J. Brad Murphy Edward E. Gbur 《In vitro cellular & developmental biology. Plant》1998,34(1):22-26
Summary A culture medium that can efficiently produce mature somatic embryos was developed for loblolly pine (Pinus taeda L.). The medium contained maltose as a carbohydrate source and polyethylene glycol as an osmoticum. This medium formulation
significantly enhanced embryo maturation efficiency compared to a medium with only maltose, or with sucrose combined with
polyethylene glycol. Maltose at 4% and polyethylene glycol at 6% resulted in the highest embryo maturation efficiency; an
average of around 100 cotyledonary embryos were produced from 1 g of embryogenic tissue. These results suggested that previous
ineffective embryo maturation in loblolly pine may be due to the lack of the proper combination of osmoticum and carbohydrate
source. This embryo maturation method also improved morphology of cotyledonary embryos of loblolly pine. 相似文献
7.
One hundred years of zygotic embryo culture investigations 总被引:4,自引:0,他引:4
Summary Isolation of zygotic embryos from seeds and their culture in a defined medium, initiated by Hanning in 1904, has proved to
be a promising method to study the factors that control growth and differentiation of embryos. Using this technique, several
investigations have focused on the carbohydrate and nitrogen nutrition during germination of cultured seed embryos and on
the effects of plant hormones on their morphogenesis. Culture of immature embryos leads to their germination into weak seeldings,
skipping the later stages of embryogenesis, by a process known as precocious germination. Progressively smaller embryos have
been cultured by supplementation of the medium with coconut milk or hormonal additives or by osmotic adjustment of the medium
by high concentrations of sucrose or mannitol. Although methods have not been developed for large-scale isolation and culture
of zygotes, zygotes of maize isolated from embryo sacs and those obtained by in vitro fertilization have been grown in culture into full-term embryos. Embryo culture techniques are widely used to rescue embryos
from seed of wide crosses which usually abort and to overcome dormancy of recalcitrant seeds. 相似文献
8.
Maggie Panaia Eric Bunn Jen McComb 《In vitro cellular & developmental biology. Plant》2011,47(3):379-386
Somatic embryogenesis was developed as a method of mass propagation for Lepidosperma drummondii (Cyperaceae), a difficult to propagate but important species for post-mining restoration in a region of high plant biodiversity,
in the southwest of Western Australia. Cultures were initiated from excised zygotic embryos, shoot cultures to rhizomes. Only
zygotic embryos of L. drummondii developed somatic embryos, with half strength Murashige and Skoog basal medium (BM) and 1 μM 2,4-dichlorophenoxyacetic acid
(2,4-D) being the most effective combination. The first culture cycle yielded a mean of 30 somatic embryos per excised zygotic
embryo forming an embryo cluster. After a further 6 wk in culture (on fresh BM with 1 μM 2,4-D), approximately 350 somatic
embryos per starting embryo cluster were recorded. Following regular sub-culturing of primary somatic embryo clusters onto
fresh media (every 4 wk), more than 74,000 secondary somatic embryos were estimated to have been produced after eight subculture
periods. This translates to between 1,000 and 2,000 somatic embryos produced from an estimated 45 mg of starting tissue per
culture plate or potentially 22,0000–44,000 somatic embryos per gram of tissue. This is a significant improvement over all
previous methods used to propagate L. drummondii, in which typical in vitro shoot multiplication rates are as low as 1.43 per 8 wk. This also compared favourably with published data and concurrent
experiments undertaken in this study (as an extra control measure) on somatic embryo production for a related species Baloskion tetraphyllum (using the same BM with 1 μM 2,4-D and coleoptile segments as explants). Various media combinations were investigated for
efficacy in converting somatic embryos into plants with best results ranging from 86% to 100% conversion for B. tetraphyllum on BM without plant growth regulators. Development of L. drummondii somatic embryos into plants was not observed on BM without plant growth regulators. However, a best result of 39% conversion
to plants was observed on BM with 1 μM thidiazuron. This is the first report of successful development of somatic embryogenesis
and conversion of somatic embryos into plants using thidiazuron for the Australian cyperale L. drummondii. 相似文献
9.
Microspores of several genotypes of Brassica campestris ssp. parachinensis have been cultured in vitro and induced to undergo embryogenesis and plant formation. Conditions favourable for embryogenesis in this species include a bud size of 2–2.9 mm, NLN-13 culture medium (Nitsch and Nitsch 1967; Lichter 1981, 1982; Swanson 1990), and an induction through exposure to 32°C for a period of 48 h. Longer periods of an elevated temperature for induction of embryogenesis resulted in embryo abortion at early developmental stages. With the protocol developed here, microspores of 60–80% of donor plants could be induced to produce embryos, although embryo yields were low, i.e. 2–5 embryos per 10 buds. Some genotypes responded to culture conditions with high numbers of embryo formation (100–150 embryos per 10 buds) but most of these subsequently failed to mature. The pattern of cell division and morphological changes of the microspores in culture were studied using various microscopic techniques. 相似文献
10.
Improved efficiency in apricot breeding: Effects of embryo development and nutrient media on in vitro germination and seedling establishment 总被引:3,自引:0,他引:3
Apricot (Prunus armeniaca L.) embryos at three stages of development were cultured on C2d, SBH and WPM media. In vitro culture produced high percentages of germination and seedlings throughout all three developmental stages. Significant media effects were noted for changes in both embryo length and weight during the culture period, as well as number of plants produced. Embryos between 5 and 9 mm (developmental stage I) germinated and developed into plants in a significantly higher percentage than in the other two more mature stages. Therefore, embryo culture can be successfully used as a tool in an apricot breeding program to obtain higher percentages of seedlings from planned hybridization or to overcome a lack of seed germination. 相似文献
11.
In-vitro culture of fertilized embryo sacs of maize: Zygotes and two-celled proembryos can develop into plants 总被引:2,自引:0,他引:2
Fertilized embryo sacs of Zea mays L. surrounded by a few layers of nucellar cells were cultured in vitro. Primary expiants contained zygotes or twocelled proembryos. Embryos of various sizes and shapes were isolated from 12–48% of explants after two weeks of culture in hormone-free media supplemented with 6–12% of sucrose. Many embryos were at the transition or proembryo stages whilst the rest were either differentiated, with a scutellum, a coleoptile and a shoot apex, or had a deformed apical part. Organogenesis started in 36–89% of embryos cultured on a semisolid medium supplemented with coconut water. Most of the embryos formed only roots but up to 9% of embryos regenerated into plants. This simple method leads the way to plant regeneration from in-vitro-manipulated zygotes or proembryos of maize.Abbreviation NBM
medium composed of N6 macronutrients, B5 micronutrients and MS vitamins
This research was supported by an I.N.R.A. post-doctoral fellowship. The authors thank R. Blanc for donor plant culture, Dr. M. Cock (Reconnaissance Cellulaire et Amélioration des Plantes, Université Lyon 1) for correction of the English and P. Audenis for micrograph development. 相似文献
12.
Summary This paper investigates maintenance and proliferation of somatic embryogenesis systems for Ulmus minor and U. glabra. Proliferation occurred with subculture of embryogenic calluses. The calluses were mainly formed by friable nodules composed
of meristematic cells organized into proembryogenic cell masses (PEMs) and thin-walled vacuolated parenchymatic cells. Cotyledonary
embryos, with procambial strands and differentiation of their vascular tissues as well as visible root meristems, were identifiable
after 18d of culture on a proliferation medium with 0.44 μM benzyladenine (BA). The shoot meristem was only occasionally well developed. Somatic embryo multiplication from elm embryogenic
calluses is a clearly asynchronic system, and PEMs as well as embryos at all stages of development are observed simultaneously
at the end of subculture period. Factors affecting the proliferation of elm embryogenic callus, such as culture medium, carbon
source and genotype, were studied. Basal medium (MS) or medium supplemented with 0.44 μM BA produced the highest number of somatic embryos. Somatic embryo production was higher with sucrose or glucose than with
maltose, and significant differences were also found among the four embryogenic lines tested. The use of liquid medium with
filter paper support is an essential step for the survival of isolated somatic embryos during the germination stage. The addition
of 0.22 μM BA′ to liquid MS medium was the best treatment for germination and plantlet conversion of elm somatic embryos. 相似文献
13.
K. Samuel D. Debashish B. Madhumita G. Padmaja Siva Ram Prasad V. Bhaskara Ramana Murthy P. S. Rao 《In vitro cellular & developmental biology. Plant》2009,45(4):466-473
The propagation of Givotia rottleriformis Griff. is difficult as a result of long seed dormancy associated with poor seed germination. The present study was undertaken
to develop a protocol to overcome seed dormancy by culture of zygotic embryo axes and then develop an efficient method for
micropropagation of Givotia. Best germination frequency (78.3%) was achieved from mature zygotic embryo axes isolated from acid-scarified fresh seeds
when cultured on Murashige and Skoog (MS) medium (half-strength major salts) with 28.9 μM gibberellic acid (GA3). Efficient plant conversion was achieved by transfer of 10-d-old germinated embryos to MS medium (half-strength major salts)
supplemented with 1.2 μM kinetin (KN) and 0.5 μM indole-3-butyric acid (IBA). However, acid scarification of 1-yr-old seeds
decreased the germination frequency of zygotic embryo axes in comparison to those obtained from non-acid-scarified seeds which
germinated (96.2%) and converted into plants (80.3%) on MS basal (half-strength major salts) medium. Multiple shoot bud induction
was achieved by culture of shoot tips derived from in vitro germinated seedlings on MS medium with 0.5 μM thidiazuron for 4 wk, and the shoots elongated after transfer to a secondary
medium with 1.2 μM KN. A maximum number of 7.8 shoots per explant with an average shoot length of 3.2 cm was achieved after
two subcultures on this medium. The in vitro regenerated shoots rooted (41.5%) on half-strength MS medium with 0.5 μM IBA. The in vitro generated seedlings and micropropagated plants were established in soil with a survival frequency of 70% and 60%, respectively. 相似文献
14.
Immature embryos culture in Italian red chicory 总被引:3,自引:0,他引:3
Varotto Serena Lucchin Margherita Parrini Paolo 《Plant Cell, Tissue and Organ Culture》2000,62(1):75-77
Chicory (Cichorium intybus L.) embryo maturation in vitro was achieved in B5 medium without growth regulators. Immature embryos were collected at different developmental stages 4–168
h after pollination. Only a few plantlets were obtained from ovules collected shortly after pollination since the embryos
at these early stages developed abnormal leaves and roots which regenerated shoots ‘via’ organogenesis. Zygotic embryos collected
24–72 h after pollination needed one month of culture in vitro before acclimation. Embryos collected at the heart or early torpedo stage of development (three days after pollination) produced
green plantlets after two weeks of in vitro culture and thus they could be transferred to the greenhouse for acclimation. Culture of zygotic embryos in vitro has shown to be a suitable technique to accelerate the breeding process in biennial cultivated Italian red chicory. In fact
it is possible to obtain plantlets ready for performing the selection for the desired agronomic traits one month after pollination.
Since flowering occurs after vernalization, the selection can be performed in the correct season before flowering.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
15.
Y. W. Kim R. Newton J. Frampton K.-H. Han 《In vitro cellular & developmental biology. Plant》2009,45(4):400-406
Embryogenic suspensor mass (ESM) was established from immature seeds of Fraser fir. The initiation frequency of ESM was dependent
on genotype, collection time, medium, and plant growth regulators (PGR) used. The ESM initiation potential was higher with
seeds collected in late June (clone 16-273, 4.7%) or early July (clone 16-45, 2.2%) and decreased as the zygotic embryos matured.
Excised proembryo stage of zygotic embryos was most appropriate to initiation of ESM. Most of the ESM arose from the seeds
that were at the proembryo stage. From the four different culture media we compared, seven ESM lines were obtained: two lines
from Murashige and Skoog (MS) medium with 4.4 μM benzyladenine (BA), one from Schenk and Hildebrandt (SH) medium with 4.5 μM
thidiazuron (TDZ), and four from SH with 4.4 μM 6-benzyladenine. However, only one ESM line from clone 16-273 (June 24, SH+TDZ)
could be proliferated in subsequent culture. Different concentrations of l-glutamine and casein hydrolysate (CH) in the medium were also compared for their effect on ESM proliferation. The highest
proliferation rate (1.16-fold) was obtained from SH medium supplemented with 250 mg/L CH and 3.42 mM l-glutamine. In contrast, the lowest rate was noted when 1,000 mg/L CH plus 3.42 mM l-glutamine (0.17-fold) was added to the medium. As for somatic embryo maturation, the highest number of mature precotyledonary
(100.1/g−1 FW ESM) or cotyledonary (64.3/g−1 FW ESM) somatic embryos was obtained on a medium containing 20 or 80 μM abscisic acid, 10% polyethyleneglycol, 4% maltose,
and 0.3% gellan gum. For germination of the somatic embryos, the cotyledonary somatic embryos derived from maturation medium
were transferred on half-strength Litvay medium containing 0.3% gellan gum. The somatic plantlets were recovered from the
germination medium and transferred to soils. 相似文献
16.
Summary Fertilized embryo sacs of Zea mays were isolated and cultured In vitro. Each explant contained one zygote and 2–4 endosperm nuclei which formed, respectively, embryo and cellular endosperm during the culture. In our double-layer/two-phase culture system, NBM medium (Mòl et al. 1993) supplemented with 0.1–1.0 mg·l–1 zeatin and 12 % sucrose showed the best results. On this medium, embryos were isolated from 37–54 % of two-week-old explants. They were similar to maize embryos developing in vivo. We have shown that development of stage-2 embryos (according to Abbe and Stein 1954) with two leaf primordia and normally differentiated provascular tissue is possible from the maize zygote in an in vitro culture system. Some embryos with enlarged and deformed scutellum or whole apical parts were also found. Up to 62 % of the embryos germinating on a simple medium regenerated into mature and fertile plants; i.e. 23 % of explants yielded plants. This unproved culture method results in better embryo differentiation and 14-fold increase of regeneration frequency than previous protocol.Abbreviations BAP
benzylaminopurin
- ZT
Zeatin 相似文献
17.
Marjatta Salmenkallio-Marttila Ulrika Kurtén Veli Kauppinen 《Plant Cell, Tissue and Organ Culture》1995,43(1):79-81
Subculture regime and carbohydrate concentration of the medium had a marked effect on the regeneration of green plantlets from mechanically isolated microspores of Hordeum vulgare L. cv. Kymppi. A sevenfold increase in the yield of green plants was obtained by shortening the suspension culture time of the developing proembryo mass from 4 to 3 weeks. A further twofold increase was obtained by increasing the maltose concentration of the microspore isolation medium and of the culture medium. Under optimal conditions, a mean of 169±97 green plants per spike were regenerated. 相似文献
18.
Laura Y. Solís-Ramos Sara Nahuath-Dzib Antonio Andrade-Torres Felipe Barredo-Pool Tomas González-Estrada Enrique Castaño de la Serna 《Biologia》2010,65(3):504-511
Capsicum chinense is recalcitrant in in vitro morphogenesis. No efficient, reproducible somatic embryogenesis regeneration system exists for this species, impeding regeneration
from transformed cells. An indirect somatic embryogenesis protocol is developed using mature C. chinense zygotic embryo segments (ZES). The ZES cultured in semi-solid Murashige-Skoog (MS) medium supplemented with 8.9 μM naphthaleneacetic
acid, 11.4 μM indoleacetic acid and 8.9 μM 6-benzylaminopurine, developed an embryogenic callus and 8% of the calli developed
somatic embryos. Torpedo-stage somatic embryos were detached from the callus and subcultured in semi-solid MS medium without
growth regulators, producing a 75% conversion rate to plantlets with well-formed root tissue. Histological analysis showed
the developed structures to have no vascular connection with the callus and to be bipolar, confirming that this protocol induced
formation of viable somatic embryos from mature C. chinense ZES. All acclimated plantlets survived under greenhouse conditions. This protocol will facilitate regeneration of genetically
transformed plants using either biolistics or Agrobacterium tumefaciens approach. 相似文献
19.
Ana Sofia Duoue Ana Sofia Pires Dulce Metelo Dos Santos Pedro Fevereiro 《In vitro cellular & developmental biology. Plant》2006,42(3):270-273
Summary Plants were suecessfully régenerated via somatic embryos from 3-yr-old cell suspension cultures of Medicago truncatula Gaertin. cv. Jemalong line M9-10a. The cultures were originally initiated from callus induced in well-expanded leaflets of
30 d in vitro-grown plants, Suspension cultures were established in stirred-liquid Murashige and Skoog (MS) basal salts and vitamins supplemented
with 2.3 μM 2.4-dichlorophenoxyacetic acid (2,4-D) and 2.3 μM kinetin (Kin) and subeultured weekly. Somatic embryogenesis induction step was conducted in liquid MS medium containing 0.45
μM 2,4-D and 0.91 μM zeatin (Zea), during 1,2, and 3wk after subculture. Induced and non-induced cultures were transferred to solid embryo proliferation
medium [EPM-MS basal salts and vitamins solidified with 0.2% (w/v) gelrite]. Somatic embryos developed until the late torpedo/dicotyledonary
stages. We found that the best condition for the development of somatic embryos was achieved when suspension cultures were
not subjected to the induction step. Induction of 1 and 2 wk led to a decrease in the recovery of somatic embryos and the
3-wk treatment resulted in no differentiation of somatic embryos. Plant regeneration was obtained in all conditions (except
for 3wk induction) when embryos were transferred to an embryo conversion medium [ECM, similar to EPM but solidified with 0.7%
(w/v) agar]. Embryo conversion rates were 54.5±1.6, 52.5±18.5, and 41.6±8.4% for 0, 1, and 2 wk induction treatments, respectively.
These plants were successfully transferred to the greenhouse where they matured and produced seeds. 相似文献
20.
Michael R. Becwar Thomas L. Noland Judith L. Wyckoff 《In vitro cellular & developmental biology. Plant》1989,25(6):575-580
Summary Quantitative data are presented on the efficiency of three stages of plant regeneration from somatic embryos of Norway spruce
(Picea abies L.): 1) Maturation, the development of immature embryos to the cotyledonary stage; 2) Germination, primary root growth; and
3) Conversion, plantlet survival and continued growth in nonaxenic conditions. Maturation frequency was calculated relative
to the number of immature somatic embryos induced to develop on the basal medium of von Arnold and Eriksson (1981). The average
number of immature somatic embryos was 700 per gram of embryogenic callus, on medium supplemented with ABA and IBA (1 μM each).
Maturation was the least efficient stage of regeneration; an average of 3% of the embryos induced to develop reached the cotyledonary
stage. Mean germination frequencies were improved on treatments which avoided immersion of the radicle in medium solidified
with agar. Whereas, 27% of the somatic embryos germinated when radicles were immersed in agar medium, 45% germinated when
placed on the surface of the medium, and 56% germinated when cotyledons were immersed in agar medium and the culture vessel
inverted. Twenty-nine percent of the somatic embryos germinatedin vitro were converted to plants. Under greenhouse conditions these plants set dormant buds, subsequently survived overwintering
(to −5°C), and renewed vegetative growth synchronously with seedlings grown under the same conditions. Our results verified
long-term (2 year) growth and development potential of conifer somatic embryo plants. 相似文献