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1.
The effects of growth regulators, cold-pretreatment of flower buds, ovule (embryo sac) developmental stage and genotype on
induction of gynogenesis in unpollinated ovule cultures were assessed in niger (Guizotia abyssinica (L. f.) Cass.). Indirect callus-mediated gynogenesis occurred in cvs JNC-6 and Ootacamund when the ovules were cultured on
MS medium supplemented with 30 g l−1 sucrose and 2,4-D either alone (0.5–2.0 μM) or in combination (2.0 μM) with different cytokinins, such as adenine, BA, 2iP
and kinetin (0.5–2.0 μM). An optimum induction of gynogenesis was fostered on medium supplemented with 2.0 μM 2,4-D and 1.0 μM
kinetin. Cold-pretreatment of flower buds had no stimulatory effect, but ovules collected one day before anthesis were most
responsive to gynogenesis. The results showed significant variations in genotypic competence for gynogenesis with cv. Ootacamund
being the most responsive (12.5%) and cv. IGP-76 the least (2.5%). Gynogenic embryos differentiated and matured on media (30 g l−1 sucrose) supplemented with 0.5 μM NAA plus 1.0 μM kinetin, and 0.5 μM ABA, respectively. The haploidy (2n = 1x = 15) of gynogenic plants was confirmed by cytological analysis. 相似文献
2.
Summary Plantlets of Capsicum annuum L. ev. Sweet Banana regenerated via somatic embryogenesis from immature zygotic embryos were capable of producing flower,
fruit, and seed when cultured in small tissue culture containers. In vitro floral buds were first formed on plantlets that grew on plantlet development medium [agar-gelled Murashige and Skoog (MS)
basal medium containing 1 mgl−1 (5.3 μM) α-naphthaleneacetic acid (NAA)] in a growth room at 22°C and continuous illumination. However, floral buds rarely developed
further into mature flowers. This problem was overcome using the vented autoclavable plant tissue culture containers. In vitro fruit formation and ripening was observed when liquid half-strength MS basal medium supplemented with 5 μg ml−1 silver thiosulfate, 1 mg l−1 (5.3 μM) NAA, and 3% sucrose was added to the surface of the plantlet development medium. Hand-pollination improved fruit set. Further
research in needed to determine why the pepper seeds formed in vitro failed to germinate. 相似文献
3.
Apomixis in <Emphasis Type="Italic">Eulaliopsis binata</Emphasis>: characterization of reproductive mode and endosperm development 总被引:1,自引:0,他引:1
Apomixis represents an alteration of classical sexual plant reproduction to produce seeds with essentially clonal embryos,
stimulating wide interest from biologists and plant breeders for its ability to fix heterosis. Eulaliopsis binata (Poaceae), is identified here as a new apomictic species. Embryological investigation indicates that the developmental pattern
of embryo sac formation in E. binata represents gametophytic apospory, the embryo originating from an unreduced cell, without fertilization and the mode of endosperm
development was autonomous. Sexual embryo sacs were found with a frequency of 1–4% depending on the biotype. The DNA content
of nuclei (C-value) in mature seeds was screened by flow cytometry (FCSS) and demonstrated that the endosperm was derived
autonomously without fertilization and the three biotypes of E. binata showed varying degrees of apomixis. The Wide-leaf type showed obligate apomixis whereas the Slender-leaf and the Red-haulm
type displayed facultative apomixis. In addition, adventitious embryos were observed on the wall of ovary, integument and
nucellus cells, indicating that E. binata produces embryos via a mixture of apospory and adventitious embryony. 相似文献
4.
Takashi Okada Andrew S. Catanach Susan D. Johnson Ross A. Bicknell Anna M. Koltunow 《Sexual plant reproduction》2007,20(4):199-211
Asexual seed formation (apomixis) in Hieracium aurantiacum occurs by mitotic embryo sac formation without prior meiosis in ovules (apomeiosis), followed by fertilization-independent
embryo and endosperm development. Sexual reproduction begins first in Hieracium ovules with megaspore mother cell (MMC) formation. Apomixis initiates with the enlargement of somatic cells, termed aposporous
initial (AI) cells, near sexual cells. AI cells grow towards sexually programmed cells undergoing meiosis, which degrade as
the dividing nuclei of AIs obscure and displace them. Following Agrobacterium-mediated transformation of an aneuploid Hieracium aurantiacum apomict, a somaclonal mutant designated “loss of apomeiosis 1” (loa1) was recovered, which had significantly lost the ability to form apomictic seed. Maternal apomictic progeny were rare and
low levels of germinable seedlings were primarily derived from meiotically derived eggs. Cytological analysis revealed defects
in AI formation and function in loa1. Somatic cells enlarged some distance away from sexual cells and unlike AI cells, these expanded away from sexual cells without
nuclear division. Surprisingly, many accumulated callose in the walls, a marker associated with meiotically specified cells.
These defective AI (DAI) cells only had partial sexual identity as they failed to express a marker reflecting entry to meiosis
that was easily detected in MMCs and they ultimately degraded. DAI cell formation did not lead to a compensatory increase
in functional sexual embryo sacs, as collapse of meiotic embryo sacs was prevalent in the aneuploid somaclonal mutant. Positional
cues that are important for AI cell differentiation, growth and fate may have been disrupted in the loa1 mutant and this is discussed.
The authors Takashi Okada, Andrew S. Catanach and Susan D. Johnson made equal contributions to the data. 相似文献
5.
Optimization of <Emphasis Type="Italic">Agrobacterium</Emphasis>-mediated transformation conditions in mature embryos of elite wheat 总被引:1,自引:0,他引:1
Immature embryos have been used frequently as target tissues in the genetical transformation of wheat. However, obtaining
a large number of high quality immature embryos throughout the year is a laborious and delicate process, because of the need
to cultivate the plants under controlled conditions. To circumvent this, we have employed mature embryos rather than immature
ones as starter explants for Agrobacterium-mediated transformation of an elite wheat (Triticum aestivum L.) cultivar EM12. The neomycin phosphotransferase ІІ (npt ІІ) and β-glucuronidase (gus) genes were used as selectable and screenable marker genes, respectively, to assess and optimize the performance of T-DNA
delivery. With the aid of an orthogonal design, the effect of four factors in combination on transfer DNA (T-DNA) delivery
was studied. These factors were preculture duration, different kinds of inoculation, length of inoculation and co-culture
condition. Optimal conditions for T-DNA delivery were obtained for mature embryos precultured for 14 days, followed by immersing
in inoculation suspension with full strength Murashige and Skoog (MS) salts in darkness at 23–25°C for 3 h, and then co-culturing
with Agrobacterium under desiccating condition in the dark at 23–24°C for 2–3 days. Complete analysis of transgene insertion demonstrated that
the optimized method for Agrobacterium-mediated transformation of mature embryos of wheat was efficient and practicable. 相似文献
6.
Summary We describe an in vitro propagation protocol for Zingiber petiolatum (Holttum), I. Theilade, a rare species from the southern part of Thailand. Fruits were surface-sterilized and seeds germinated
on Murashige and Skoog medium (MS) medium supplemented with 3% sucrose. Three-month-old seedlings were used as initial plant
material for in vitro propagation. Terminal buds of the plants were inoculated on MS medium containing 6-benzylaminopurine (BA; 2.2–35.5 μM) alone or in combination with 1-naphthaleneacetic acid (0.5 μM). Eight weeks after inoculation, the cultures were transferred to MS medium without plant growth regulators for 4wk. The
cultures transferred from MS medium with 17.8 μM BA revealed the highest shoot induction rate of 6.1±0.7 shoots per explant. Rooting was spontaneously achieved in MS medium
without plant growth regulators. Rooted plants were successfully transplanted to soil. 相似文献
7.
Jing Li Yang Yu Da Niu Chuan Ping Yang Gui Feng Liu Cheng Hao Li 《Plant Cell, Tissue and Organ Culture》2011,106(3):391-399
Somatic embryogenesis (SE) was induced in female flower buds from mature Schisandra chinensis cultivar ‘Hongzhenzhu’. Somatic embryo structures were induced at a low frequency from unopened female flower buds and excised
unopened on Murashige and Skoog (MS) agar medium containing 4.0 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D). Friable embryogenic calli were induced from somatic embryo structures after three
to four subcultures on initiation medium. The frequencies of mature somatic embryo germination and plantlet conversion were
low, but increased in the presence of gibberellic acid (GA3). Some germinated somatic embryos could form friable embryogenic calli on medium without plant growth regulators (PGRs).
The germination and conversion frequencies of somatic embryos from embryogenic calli induced using PGR-free medium were higher
than for somatic embryos from embryogenic calli induced on medium containing 2,4-D. Most somatic embryos from 2,4-D-induced
embryogenic calli had trumpet-shaped embryos, and most somatic embryos from PGR-free medium–induced embryogenic calli had
two or three cotyledons. Histological observation indicated that two- and three-cotyledon embryos had defined shoot primordia,
but most of the trumpet-shaped embryos yielded plantlets that lacked or had poorly developed meristem tissue. Cytological
and random amplification of polymorphic DNA (RAPD) analyses indicated no evidence of genetic variation in the plantlets of
somatic embryo origin. 相似文献
8.
9.
To investigate the biocontrol effectiveness of the antibiotic producing bacterium, Pseudomonas aureofaciens 63–28 against the phytopathogen Rhizoctonia solani AG-4 on Petri plates and in soybean roots, growth response and induction of PR-proteins were estimated after inoculation
with P. aureofaciens 63–28 (P), with R. solani AG-4 (R), or with P. aureofaciens 63–28 + R. solani AG-4 (P + R). P. aureofaciens 63–28 showed strong antifungal activity against R. solani AG-4 pathogens in Petri plates. Treatment with P. aureofaciens 63–28 alone increased the emergence rate, shoot fresh weight, shoot dry weight and root fresh weight at 7 days after inoculation,
when compared to R. solani AG-4; P + R treatment showed similar effects. Peroxidase (POD) and β-1,3-glucanase activity of P. aureofaciens 63–28 treated roots increased by 41.1 and 49.9%, respectively, compared to control roots. POD was 26% greater in P + R treated
roots than R. solani treated roots. Two POD isozymes (59 and 27 kDa) were strongly induced in P + R treated roots. The apparent molecular weight
of chitinase from treated roots, as determined through SDS-PAGE separation and comparison with standards, was about 29 kDa.
Five β-1,3-glucanase isozymes (80, 70, 50, 46 and 19 kDa) were observed in all treatments. These results suggest that inoculation
of soybean plants with P. aureofaciens 63–28 elevates plant growth inhibition by R. solani AG-4 and activates PR-proteins, potentially through induction of systemic resistance mechanisms. 相似文献
10.
Wen Liu Xuesen Chen Guanjun Liu Qing Liang Tianming He Jianrong Feng 《Plant Cell, Tissue and Organ Culture》2007,88(3):289-299
Embryo rescue technique was used successfully to produce interspecific hybrids by crossing peach (P. persica) as a female parent with apricot (P. armeniaca) and plum (P. salicica). In those crosses that had ‘Yuhualu’ or ‘Zhonghuashoutao’ as female parents, hybrid embryos aborted from the 7th or 8th
week after pollination mainly due to post-pollination incompatibility. An embryo rescue protocol was established to rescue
such embryos and recover hybrid plants. Modified half-strength MS medium containing 4 mg l−1 6-BA and 0.5 mg l−1 IBA produced up to 90% germination in the embryos. Modified MS medium with 1.0 mg l−1 6-BA and 1.0 mg l−1 IBA gave the highest bud induction and multiplication whereas modified MS medium containing 0.5 mg l−1 IAA and 0.2 mg l−1 NAA gave the best rooting percentage. All the hybrids obtained using this embryo rescue technique were verified using simple
sequence repeat (SSR) markers. A series of pollen treatments were carried out to partially overcome pre-pollination incompatibility,
and it was found accidentally that pollen treatment with electrostatic field not only improved pollen germination but also
increased the multiplication coefficient of embryo-induced shoots. 相似文献
11.
D. N. Vlachostergios A. G. Mavromatis S. K. Kantartzi D. G. Roupakias 《Plant Cell, Tissue and Organ Culture》2007,88(1):109-115
The in vitro response of ovules obtained after pollination of cotton flowers with pollen from Abelmoschus esculentus was studied. For this, 492 cotton flowers from five G. hirsutum varieties, four G. barbadense varieties and 10 F1 interspecific hybrids, were pollinated with pollen from A. esculentus and 5,069 ovules were cultured in vitro. From the cultured ovules, 69 embryos were isolated and 16 of them grew into plants.
However, only three of them survived after transplantation. Finally, one plant which originated from the interspecific cross
(B403 × Acala Sindos) × A. esculentus reached maturity. The mature plant (Pa0) had no morphological traits from A. esculentus. On the contrary, traits from both cotton species were observed. The flowcytometric analysis of the Pa0 plant indicated that
it was hypoaneuploid. Root tip chromosome counts of its offsprings revealed a progressive chromosome increase from the Pa1
to Pa4 generation. Plants with 52 chromosomes or hypoaneuploids with a lower level of chromosomes (46–51) could be isolated
from the Pa4 generation. These plants exhibited morphological traits from both cotton species and they were fertile. No signs
of A. esculentus morphological characteristics were observed in these plants. It was concluded that aneuploid partial interspecific cotton
plants could be produced after pollination of cotton interspecific hybrids with pollen from A. esculentus and application of an in-ovule embryo rescue technique. 相似文献
12.
A microspore culture protocol for Brassica oleracea of Indonesian origin (cv. ‘Kemeh’) has been successfully established. A high number of embryos formed with high microspore
density i.e. 15 × 104 cells/ml. Embryo formation was improved by using flower buds (4.5–4.6 mm in length) as explants, a temperature treatment
at 30.5°C for 48 h and then transfer to 25°C continuously until embryos formed. A total of 295 embryos were obtained from
189 buds, 30% of which were abnormal (i.e. with an abnormal cotyledon or lacking hypocotyls). All normal embryos that grew
and survived, 165 in total, were successfully transferred to soil and grew well in plastic bags (15 cm in diameter) containing
a mixture of burned-rice husk and organic manure (1:1, v/v). 相似文献
13.
Edyta Skrzypek Ilona Czyczyło-Mysza Izabela Marcińska Maria Wędzony 《Plant Cell, Tissue and Organ Culture》2008,94(2):131-137
Anthers cultures of six Polish cultivars of pasture lupin (Lupinus L.) were examined for their androgenic response. Anthers with microspores at the uninucleate stage were isolated from flower
buds and cultured in liquid media. Better viability of androgenetic structures was obtained when donor plants had grown under
field as opposed to greenhouse conditions. A density of five anthers per 0.5 ml medium was more conducive to androgenetic
induction than 25 anthers per 0.5 ml medium. Addition of 5% maltose to the induction medium and culture at 25°C without pre-treatment
of flowers, buds or anthers promoted microspore release and division. The greatest frequency of androgenic callus, ~70% was
developed from cvs. Katon, Wat (white lupin), in contrast to cvs. Legat, Juno (yellow lupin), Polonez and Sonet (narrow-leafed
lupin) with callus induction ~30–40%. Despite various combinations of media tested, plant regeneration was not obtained from
anther derived callus. 相似文献
14.
The Drosophila melanogaster genes zerknüllt (zen) and fushi tarazu (ftz) are members of the Hox gene family whose roles have changed significantly in the insect lineage and thus provide an opportunity to study the mechanisms
underlying the functional evolution of Hox proteins. We have studied the expression of orthologs of zen (DpuHox3) and ftz (Dpuftz) in the crustacean Daphnia pulex (Branchiopoda), both of which show a dynamic expression pattern. DpuHox3 is expressed in a complex pattern in early embryogenesis, with the most anterior boundary of expression lying at the anterior
limit of the second antennal segment as well as a ring of expression around the embryo. In later embryos, DpuHox3 expression is restricted to the mesoderm of mandibular limb buds. Dpuftz is first expressed in a ring around the embryo following the posterior limit of the mandibular segment. Later, Dpuftz is restricted to the posterior part of the mandibular segment. This is the first report of expression of a Hox3 ortholog in a crustacean, and together with Dpuftz data, the results presented here show that Hox3 and ftz have retained a Hox-like expression pattern in crustaceans. This is in accordance with the proposed model of Hox3 and ftz evolution in arthropods and allows a more precise pinpointing of the loss of ftz “Hox-like behaviour”: in the lineage between the Branchiopoda and the basal insect Thysanura. 相似文献
15.
A high-frequency and simple procedure for Agrobacterium tumefaciens-mediated genetic transformation of the medicinal plant Salvia miltiorrhiza was developed. Leaf discs were pre-cultured on MS medium supplemented with 6.6 μmol l−1 BAP and 0.5 μmol l−1 NAA for one day, then co-cultured with A. tumefaciens strain EHA105 harboring the plasmid pCAMBIA 2301 for three days on the same medium. Regenerated buds were obtained on selection
medium (co-culture medium supplemented with 60 mg l−1 kanamycin and 200 mg l−1 cefotaxime) after two cycles’ culture of 10 days each and then transferred to fresh MS medium with 60 mg l−1 kanamycin for rooting. Fifteen days later, the rooted plantlets were obtained and then successfully transplanted to soil.
The transgenic nature of the regenerated plants was confirmed by PCR, Southern hybridization analysis and GUS histochemical
assay. Averagely, 1.1 independent verified transgenics per explant plated were obtained through this protocol. Adopting this
procedure, positive transformed plants could be obtained within 2–3 months from mature seeds germination to transplant to
soil, and more than 1,000 transgenic plants with several engineered constructs encoding different genes of interest were produced
in our lab in the past two years. 相似文献
16.
T. Zhang 《In vitro cellular & developmental biology. Plant》2007,43(2):91-94
This study investigated the factors affecting in vitro flowering of Perilla frutescens. The shoots regenerated from cotyledonary and hypocotyl explants cultured on Murashige and Skoog (MS) medium supplemented
with benzyladenine (BA) and indole-3-acetic acid, each at 0.5 mg l−1, were excised and transferred to MS medium containing 30 g l−1 of sucrose, 8.25 g l−1 of ammonium nitrate, and 1.0 mg l−1 of BA. After 40 d of culture, 86.2% of shoots flowered and most of which self-fertilized in vitro and produced mature fruits with viable seeds. These seeds were germinated and plants were grown to maturity and flowered
in soil under greenhouse conditions. The in vitro flowering system reported in this study may facilitate rapid breeding of P. frutescens and offers a model system for studying the physiological mechanism of flowering. 相似文献
17.
C. Douglas Boyette Mark A. Weaver Robert E. Hoagland Kenneth C. Stetina 《World journal of microbiology & biotechnology》2008,24(11):2721-2726
A mycelial formulation of the fungus Myrothecium verrucaria (IMI 361690) containing 0.20% Silwet L-77 surfactant was found to be highly efficacious in controlling the exotic invasive
weed kudzu. The mycelium can be rapidly (48–72 h) produced in several media, including an inexpensive soy flour–corn meal
medium. Mycelial yields were 2, 10, and 25 g dry weight l−1 in Czapek-Dox, Richard’s V-8, and soy flour–corn meal media, respectively. Scale-up production in soy flour–corn meal medium
using laboratory fermenters (10–25 l), resulted in a mycelial formulation that caused 90% mortality of naturally-occurring
mature (0.9–1.0 m in height) kudzu within 48 h after application in field experiments. HPLC analyses revealed that the mycelium
produced in this liquid culture contained no detectable amounts of the trichothecene mycotoxins roridin A and verrucarin A
(limit of detection 2 μg ml−1). This has resulted in a safer, yet effective bioherbicidal product. We anticipate that these findings should improve the
probability of EPA registration and subsequent commercial development of this bioherbicide. 相似文献
18.
Eugène K. Konan Justin Y. Kouadio Albert Flori Tristan Durand-Gasselin Alain Rival 《In vitro cellular & developmental biology. Plant》2007,43(5):456-466
In vitro rooting of oil palm shoots derived from somatic embryos was achieved through a single-phase protocol in which three shoots
are cultured in the same culture tube on an α-naphtaleacetic acid-enriched culture medium. Rooting performance was dependent
on both the genetic origin and initial size of the shoot explants. All shoots from a given tube showed a tendency to give
roots of the same type, independent of the original size of the explant. Whatever the clonal line, longer-size shoots (L-type:
>9 cm) showed higher rooting rates than medium-size (M-type: 7–9 cm) and short-size ones (S-type: 5–7 cm). When groups of
three shoots from the same clonal line were rooted together in the same culture tube, the combination of plant size within
the group impacted overall quality of rooting. Within triplets of shoots containing more than one short individual, the probability
of obtaining adequate rooting was low. Similarly, when more than one long shoot was included in the triplet rooting, quality
was also poor. By avoiding such combinations, the rate of well-rooted plantlets increased by 25%, with a maximum of 66% when
triplets of S/M/L combination were used. Smaller shoots, which usually showed poor rooting performance, were therefore found
to benefit from the presence of their neighbors. This interaction between the sizes of individuals in a given tube was found
to be associated with a within-tube correlation effect, a phenomenon previously described as “event coupling,” which was estimated
using a distorted binomial-type distribution of probabilities. The resulting calculation of a coupling factor (average r = 0.60) explains the behavior of shoots within the same culture tube and their average rooting performance. Modeling of the
interactions that occurred during in vitro rooting is described here and is recommended for improvement of this critical step in micropropagation. 相似文献
19.
Ravinder Kaur Grewal Monika Lulsdorf Janine Croser Sergio Ochatt Albert Vandenberg Thomas D. Warkentin 《Plant cell reports》2009,28(8):1289-1299
This is the first report on the production of double-haploid chickpea embryos and regenerated plants through anther culture
using Canadian cultivar CDC Xena (kabuli) and Australian cultivar Sonali (desi). Maximum anther induction rates were 69% for
Sonali and 63% for CDC Xena. Under optimal conditions, embryo formation occurred within 15–20 days of culture initiation with
2.3 embryos produced per anther for CDC Xena and 2.0 embryos per anther for Sonali. For anther induction, the following stress
treatments were used: (1) flower clusters were treated at 4°C for 4 days, (2) anthers were subjected to electric shock treatment
of three exponentially decaying pulses of 50–400 V with 25 μF capacitance and 25 Ω resistance, (3) anthers were centrifuged
at 168–1,509g for 2–15 min, and finally (4) anthers were cultured for 4 days in high-osmotic pressure (563 mmol) liquid medium. Anthers
were then transferred to a solid embryo development medium and, 15–20 days later, embryo development was observed concomitant
with a small amount of callus growth of 0.1–3 mm. Anther-derived embryos were regenerated on plant regeneration medium. Electroporation
treatment of anthers enhanced root formation, which is often a major hurdle in legume regeneration protocols. Cytological
studies using DAPI staining showed a wide range of ploidy levels from haploid to tetraploid in 10–30-day-old calli. Flow cytometric
analysis of calli, embryos and regenerated plants showed haploid profiles and/or spontaneous doubling of the chromosomes during
early regeneration stages. 相似文献
20.
Ryoo N Yu C Park CS Baik MY Park IM Cho MH Bhoo SH An G Hahn TR Jeon JS 《Plant cell reports》2007,26(7):1083-1095
To elucidate the role of SSIIIa during starch synthesis in rice (Oryza sativa L.) endosperm, we characterized null mutants of this gene, generated by T-DNA insertions. Scanning electron microscope (SEM)
analysis revealed that the starch granules in these mutants are smaller and rounder compared with the wild type controls,
and that the mutant endosperm is characterized by a loosely packed central portion exhibiting a floury-like phenotype. Hence,
the OsSSIIIa (Oryza sativa SSIIIa) mutations are referred to as white-core floury endosperm 5-1 (flo5-1) and flo5-2. Based upon their X-ray diffraction patterns, the crystallinity of the starch in the flo5 mutant endosperm is decreased compared with wild type. Through determination of the chain-length distribution of the mutant
endosperm starch, we found that flo5-1 and flo5-2 mutants have reduced the content of long chains with degree of polymerization (DP) 30 or greater compared with the controls.
This suggests that OsSSIIIa/Flo5 plays an important role in generating relatively long chains in rice endosperm. In addition,
DP 6 to 8 and DP 16 to 20 appeared to be reduced in endosperm starch of flo5-1 and flo5-2, whereas DP 9 to 15 and DP 22 to 29 were increased in these mutants. By the use of differential scanning calorimetry (DSC),
the gelatinization temperatures of endosperm starch were found to be 1–5°C lower than those of the control. We propose a distinct
role for OsSSIIIa/Flo5 and the coordinated action of other SS isoforms during starch synthesis in the seed endosperm of rice. 相似文献