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1.
Lone Bruun 《Sexual plant reproduction》1991,4(1):64-72
Summary Fertilized ovules from sugar beet, Beta vulgaris L., of different intra- and interspecific crosses have been grown under in situ and in vitro conditions and investigated by light microscopy. Selected anatomical parameters were observed and entered in a computer program for statistical treatment. After a few days in culture the cells of the inner integument epidermis develop reticulate wall thickenings and their content of tannins decrease. Likewise, the starch content in the outer integument decreases and no real seed coat is formed. The funiculus tissue increases its metabolic activity, i.e., abundant accumulation of protein and starch. Callus or callus-like proliferations develop in the nucellus and the suspensor, but only rarely in the embryo or endosperm. However, the embryo may show an irregular morphology. Very rapid metabolism of starch in the suspensor may be related to the ability of the embryo to survive the first days in culture. Generally, the cellular responses, most significant in the maternal sporophytic tissue and the suspensor rather than in the embryo and endosperm, can be explained as structural adaptations to alternative pathways of nutrient supply. 相似文献
2.
Arabinogalactan proteins (AGPs) have been implicated in plant development including sexual plant reproduction. In this paper,
the expression of AGPs and the effects of β-glucosyl Yariv reagent (βGlcY, which binds arabinogalactan proteins) in embryo
development and cotyledon formation were investigated. Immunofluorescence assay displayed that the expression of AGPs labeled
with antibody JIM13 was developmentally regulated. In early stages, AGPs were evenly distributed in the whole embryo, except
for a short polar expression in the basal suspensor cell. In the globular stage of embryo, AGPs were condensed in the embryo
proper (EP), apex of the EP, and at the juncture of the EP and suspensor. In heart-shaped embryo, APGs were only present at
the juncture of the EP and suspensor. Immunogold labeling assay showed that the strong expression of AGPs at the juncture
of the EP and suspensor was localized in the cell wall. Provision of βGlcY to the in vitro ovule culture medium caused delayed
growth of embryos, cotyledon defect and abnormal venation pattern. Consequently, βGlcY induced the death of defective seedlings
with the characteristics of deformed or irregular single cotyledon. Our results suggested that AGPs play functional roles
in embryo development, cotyledon formation and seedling morphology establishment in Nicotiana tabacum L. 相似文献
3.
J. A. Smith S. L. Desborough 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1986,72(3):346-352
Summary To investigate the mechanisms of seed failure in intraspecific and interspecific crosses of Solanum two diploid, S. commersonii and Group Phureja, and one tetraploid species, S. acaule, species were crossed and the seeds were analyzed for embryo and endosperm development. Many seeds of certain crosses observed seven days after pollinations were found to contain abnormal embryos and degenerating endosperms. In some cases seeds contained an embryo with no endosperm, or an endosperm with no embryo. Other interspecific crosses which were predicted to fail actually produced seeds with normally developed embryos and endosperms. To further characterize the intra- and interspecific embryos and endosperms the nuclear DNA was measured. There are several ways to explain the ploidy levels of embryos and endosperms among the crosses, the occurrence of unreduced gametes in some cases and genomic instability in other cases. The latter resulted in chromosome loss at meiotic and mitotic divisions. Genomic balance in interspecific seeds is critical to both embryo and endosperm development.Scientific Journal Series Article No. 14636 of the Minnesota Experiment Station 相似文献
4.
Summary The frequency of aborted fruits and the changes and abnormalities that occur during the embryo development in intraspecific crosses of sweet-potato Ipomoea batatas (2n=6x=90) and interspecific crosses between I. batatas and I. trifida (2n=2x=30) were investigated in order to study the causes of the low seed production. Three genotypes of I. batatas and 18 genotypes of I. trifida were intermated. The frequency of aborted fruits was below 25% in the intraspecific crosses and over 90% in the interspecific crosses. Paraffin sections were used to examine the developmental stages of fruits and seeds. Embryos in different developmental stages were observed to determine the stage of abortion. These observations permitted the identification of developmental stages of embryo rescue in interspecific crosses. There were no significant differences in the frequency of embryo abortion before the early globular stage among female sweet-potato progenitors for the intraspecific and interspecific crosses. The frequency of the late occurrence of embryo abortion (when embryo abortion occurs after the pre-globular stage) was higher in interspecific crosses (19.1%) than in intraspecific crosses (5.5%). The frequency of the late occurrence of embryo abortion in interspecific crosses was higher at the globular stage (9.6%) than at the heart stage (4.3%). Providing that embryo rescue is conducted in interspecific crosses, the estimated number of potentially viable embryos could be increased: 30 times with embryos at the globular stage; 20 times with embryos at the heart stage; and 11 times if embryos at the torpedo stage were used for the rescue with respect to the seed set. The results suggested that the appropriate time for embryo rescue in interspecific crosses is at the globular stage. If embryos could be rescued at the globular stage, it would be possible to increase the number of surviving embryos up to 30 times in interspecific crosses and 0.02 times in intraspecific crosses with respect to natural conditions without embryo rescue.This research was initiated during sabbatical of M.I. at the Asian Vegetable Research and Development Center (AVRDC) in Taiwan 相似文献
5.
通过qRT-PCR对毛竹相关成花基因PheTFL1的表达进行研究,为毛竹开花机理的研究提供理论依据.从毛竹UBC18、PP2A和EF1α等9个候选内参基因中筛选出在叶、幼嫩花序、花序轴、枝、竹青等11个组织器官中都稳定表达的PP2A用于毛竹PheTFL1基因qRT-PCR结果的校正.结果显示:PheTFL1基因在开花竹叶、枝和竹青中低丰度表达,与未开花竹差异不显著,但在花和花序轴中高丰度表达;在实生苗叶和根中高丰度表达,在实生苗茎中低丰度表达.PheTFL1基因在具有分生能力的幼嫩组织中高丰度表达,说明其不仅参与花发育的调控,还参与了分生组织生长的调控. 相似文献
6.
Cotton ovule culture: A tool for basic biology, biotechnology and cotton improvement 总被引:1,自引:0,他引:1
Barbara A. Triplett 《In vitro cellular & developmental biology. Plant》2000,36(2):93-101
Summary Nearly 30 years ago the conditions for culturing immature cotton ovules were established to serve as a working research tool
for investigating the physiology and biochemistry of fiber development. Not only has this tissue culture method been employed
to characterize the biochemistry of plant cell expansion and secondary cell wall synthesis, but ovule cultures have contributed
to numerous other aspects of plant cell physiology and development as well. In addition to basic studies on fiber development,
cotton ovule cultures have been used to examine plant-fungal interactions, to model low temperature stress responses, to elucidate
the pathways responsible for pigment formation in naturally pigmented fiber and to probe how cytoskeletal elements regulate
cell wall organization. Success in rescuing Gossypium interspecific hybrids was dependent on ovule culture media formulations that could support early embryo development in ovulo. As tissues produced in culture are analyzed by increasingly more sophisticated techniques, there appear to be some differences
between ovule growth in planta and ovule growth in vitro. Discerning how ovule culture fiber development is different from fiber development in field-grown plants can contribute
valuable information for crop improvement. Cotton ovule cultures are an especially attractive model system for studying the
effects of gravity on cell elongation, cellulose biosynthesis and embryo development and are excellent targets for examining
transient expression of introduced gene constructs. With only minor modification, the procedure originally described by C.
A. Beasley and I. P. Ting for growing cotton ovules in vitro will continue to be useful research tool for the foreseeable future. 相似文献
7.
Exogenous plant growth regulators are known to increase the efficiency of interspecific and intergeneric crosses. In vitro floret culture provides a defined system for assessing the importance of various plant growth regulators on the determinants of haploid production efficiency (seed set, embryos per seeds, and plants per embryos) in Hordeum vulgare × Hordeum bulbosum crosses. The individual and combined effects of three plant growth regulators (2,4-D, GA3 and kinetin) on in vitro seed growth, embryo development and haploid production efficiency were tested in floret culture of the cross H. vulgare, cultivar Klages × H. bulbosum. All treatments, except kinetin alone, produced larger seeds and more embryos/100 seeds than the control (no plant growth regulator). 2,4-D alone was superior to GA3 alone in haploid production efficiency (70.6 vs. 51.5) as measured by the number of plants regenerated/100 florets pollinated. Although kinetin +2,4-D+GA3 produced the largest seeds and embryos, no advantage over 2,4-D alone was observed in haploid production efficiency. 2,4-D alone or kinetin +2,4-D are recommended for the purpose of barley haploid production in floret culture using the bulbosum method.Abbreviations 2,4-D
2,4-dichlorophenoxyacetic acid
- GA3
gibberellic acid 相似文献
8.
M. G. M. Van Creij J. L. van Went D. M. F. J. Kerckhoffs 《Sexual plant reproduction》1997,10(4):241-249
The development of the embryo and endosperm has been investigated in an intraspecific Tulipa gesneriana cross and in the incongruent cross T. gesneriana ×T. agenensis at intervals of 10 days, from 12 to 82 days after pollination (DAP). In both tulip crosses, the zygote gives rise to an apparently
undifferentiated cell mass, the proembryonal cell mass, on which a suspensor then develops. Subsequently, a globular embryo
is formed on top of the suspensor. This embryo finally elongates, giving rise to a spindle-shaped embryo. The cellular endosperm
fills the whole embryo sac in mature seeds, except for a region immediately around the embryo. In both crosses, aberrant developments
were found. In the intraspecific T. gesneriana cross, the pollen tubes did not open in a number of ovules. In other ovules, the pollen tubes seemed to have opened, but an
embryo or endosperm was not found or only endosperm was observed. In the cross T. gesneriana ×T. agenensis, fewer pollen tubes entered the ovules than in the intraspecific T. gesneriana cross. The ovules with embryo and endosperm formation of the incongruent interspecific cross showed, in general, retarded
development in comparison with the intraspecific T. gesneriana cross. The first globular embryos and spindle-shaped embryos were found at the later fixation dates and the relatively lower
number of spindle-shaped embryos at 82 DAP had a shorter average length. The number of ovules with deformations in embryo
and/or endosperm development was also higher in the cross T. gesneriana × T. agenensis in comparison with the intraspecific T. gesneriana cross. Between 87% and 100% of the ovules with embryo and endosperm development showed normal development in the intraspecific
T. gesneriana cross, while in the incongruent interspecific cross, from 22 DAP, between 17% and 56% of the ovules showed normal development.
Of those ovules with aberrations in embryo and/or endosperm formation, about 80% had a deformed endosperm, of which more than
50% also contained a deformed embryo. Embryos of the incongruent cross might be saved by the application of embryo rescue
techniques.
Received: 10 December 1996 / Revision accepted: 23 April 1997 相似文献
9.
The effects of genotype, pollen or growth regulator-pretreatment of pistils, developmental stage of the ovule (embryo sac)
and culture media on induction of gynogenesis, and subsequent plantlet regeneration in vitro were assessed in interspecific
Gossypium barbadense × G. hirsutum cotton hybrids. Gynogenesis occurred in all genotypes used when the pistils had been pre-treated with pollen from Hibiscus cannabinus and ovaries were harvested 5 or 10 days after anthesis. The use of culture media, SH and MS, showed no significant differences
in responding ovules, embryogenic ovules or embryo germination frequency. Recovered progeny were characterized cytogenetically
and microscopically to help documenting their reproductive basis. Root tip chromosome counts of 17 plants established from
ovule culture revealed that chromosome numbers ranged from 27 to 44. Although the reproductive mechanisms need to be characterized
more extensively by cytological and molecular means, the observations suggest that gynogenesis in cotton involves some unusual
reproductive events. Aneuploids could be useful for functional genomic characterization of genome shock, deletion mapping,
and germplasm introgression. 相似文献
10.
通过对受精后烟草(Nicotiana tabacumL.)胚珠的体外培养,建立了一个简便、实用、高频率的胚胎发生研究系统。采用MS培养基附加6%蔗糖,然后换以2%蔗糖对烟草胚珠进行培养,结果受精后胚珠在体外可以完成正常的胚胎发生并可直接萌发成幼苗。追踪观察表明,合子体外胚胎发生过程中关键发育事件,如合子休眠期间的定向生长、一次不对称分裂的完成、胚柄的形成和解体、胚的分化等过程均可在体外重现。体外培养形成的胚珠及胚胎在形态上与自然状态下形成的胚珠及胚胎几乎没有差异。此体系操作简单,稳定性好,且关键发育事件的时空调控与自然胚胎发育进程相吻合。 相似文献
11.
Jinling Meng Mei Lu 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1993,87(1-2):238-242
To investigate the cause of variation in the interspecific crossability of Brassica napus, three different genotypes were studied in respect of their reproductive behavior after pollination with B. juncea. There were great differences among maternal genotypes in allowing foreign pollen to germinate on and penetrate into their stigmas, leading to a wide diversity of interspecific fertilization. The division of the hybrid primary endosperm nucleus and zygote appeared normal in all combinations of crosses. While the abundant free nuclei of the endosperm developed properly and never became cellular, the embryos degenerated as early as 10 days after pollination when the cultivar Rucabo, which had the highest fertilization record with species of B. juncea, was involved. When 81007 was used as female parent, the endosperm grew a little but the embryo halted at the heart-torpedo stage. Lack of nourishment might be responsible for the observed embryo abortion. Among the sic hybrid combinations, the cross 84014A x Changyang hunagjie was the only one where endosperm tissue was observable and an abnormal embryo occurred prior to cellular endosperm formation. Apart from the three typical embryological features, significant variation was also demonstrated among each of the cross combinations. Genetic diversity appears to exist not only between varieties, but also within cultivars. In addition, methods for developing interspecific crossable lines are discussed. 相似文献
12.
Summary Interspecific hybridization between Vigna unguiculata and V. vexillata always failed: no seed was obtained in both crossing directions. Two different barriers to crossability were found: a pre-zygotic barrier and a post-zygotic one. Many abnormalities were observed in pollen-tube development, which reduced the percentage of fertilization to 18–30%. Differences in the percentage of fertilization were detected between the two accessions of V. vexillata involved in the interspecific crosses. The development of the interspecific embryo was analyzed and the embryo and endosperm nuclei always degenerated 5–8 days after pollination. The growth of the embryo stopped at a globular stage, which is too early for excision and in vitro culturing. 相似文献
13.
J. Bohdanowicz 《Protoplasma》1987,137(2-3):71-83
Summary The development of the suspensor (consisting of a basal cell and a few chalazal cells) inAlisma plantagoaquatica andA. lanceolatum was investigated using cytochemical methods, light and electron microscopy. The basal cell becomes differentiated during the first three days of embryo development. As a result of endopolyploidization the volume of the nucleus rapidly increases, as does the quantity of chromatin it contains and the size of the nucleolus. As basal cell grows, its cytoplasm increases in volume and the number of organelles increase, and wall ingrowths begin to form on the walls at the micropylar pole of the cell. The full development and functioning of the suspensor occurs during the next three days. The enormous basal cell then attains its maximum degree of differentiation: its nucleus reaches a ploidy of 256n or 512n, the micropylar transfer wall is fully developed, as is the cytoplasm, rich in proteins, ribonucleic acids (RNA) and organelles, particularly dictyosomes and long cisternae of the rough endoplasmic reticulum. The chalazal suspensor cells joining the embryo proper to the basal cell also become differentiated. In the seven-day embryo the suspensor begins to degenerate which coincides with the cellularization of the endosperm at the micropylar pole of the embryo sac. The senescence of the suspensor involves the degradation of the nucleus, increasing cytoplasmic vacuolization, and a distinct decrease in protein and RNA content, first in the basal cell, then in the chalazal suspensor cells. Analysis of the development and ultrastructure of the basal suspensor cell suggests that it plays the role of an active metabolic transfer cell, translocating nutrients from the maternal tissues via the chalazal suspensor cells to the growing embryo proper. 相似文献
14.
G. Chichiriccò 《Plant Systematics and Evolution》1996,201(1-4):83-92
The reproductive system was studied inCrocus genus (Iridaceae) following intra- and interspecific pollination, by using light and scanning electron microscopy. The results suggest that the stigma-style tract of theCrocus pistil is a mere promoter of pollen tube growth, while intra- and interspecific discrimination of compatible and incompatible pollen occurs in the ovarian tract. Here, the transmitting tissue consists of special epidermal cells, whose granular or floccular secretions provide the selective medium for the growth of pollen tubes. The ovarian self-incompatibility (SI) is widespread within the genus, resulting in a partial or complete suppression of self-fertilization. Moreover, postzygotic SI mechanisms, as well as postzygotic mechanisms of unknown nature, seem to be recurrent and both are responsible for seed abortion. The interspecific ovarian incompatibility concerns only unrelated crosses; crosses between related fertile species succeed both in fertilization and seed-set. 相似文献
15.
T. J. McCoy L. Y. Smith 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1986,71(6):772-783
Summary New interspecific hybrids between alfalfa (Medicago sativa L.) and several perennial Medicago species were obtained by embryo rescue techniques. The methodology, designated ovule-embryo culture, involved preculturing the fertilized ovule (10 to 20 days post-pollination) for a period of six to 12 days followed by excision and direct culture of the embryo. Placement of the hybrid embryo directly onto culture medium without the interim ovule culture was unsuccessful. Ovule culture to germination without removing the embryo also was unsuccessful. Ovule-embryo culture was essential for recovering interspecific hybrids between diploid alfalfa (2n=2x=16) and the following diploid (2n=2x=16) species: M. hybrida Traut., M. marina L., M. papillosa Boiss., M. rhodopea Velen. and M. rupestris M.B. In addition, trispecies hybrids between M. sativa x M. dzhawakhetica Bordz. F1 hybrids (2n=3x=24) and either M. cancellata M.B. (2n=6x=48) or M. saxatilis M.B. (2n=6x=48) were obtained from ovuleembryo culture. Media manipulations using M. sativa x M. rupestris F1 and first backcross generation embryos demonstrated the optimum concentration of 12.5 mM NH4
+ for successful embryo rescue; ammonium salt formulation (whether chloride, nitrate or sulfate) was not critical. From a few thousand crosses, hybrids between M. sativa and either M. rhodopea or M. rupestris were recovered relatively efficiently with 157 and 66 hybrids, respectively. However, only 13 hybrids between M. sativa and M. papillosa were obtained from more than 2,000 crosses, and just two hybrids each have been recovered from the combinations M. sativa x M. hybrida and M. sativa x M. marina from 2,000 to 3,000 crosses. The predominant chromosome number between diploid alfalfa and the other diploid perennial species was 2n=2x=16. Morphology of the hybrids was generally intermediate. Electrophoretic analysis of the F1 hybrids and parental clones on uniform or gradient polyacrylamide gels demonstrated that peroxidase phenotypes could be used to confirm hybridity. For all interspecific combinations there was at least one peroxidase isozyme unique to the wild species that was present in the F1 interspecific hybrid. 相似文献
16.
为探讨多花地宝兰(Geodorum recurvum)胚胎发育的系统分类学意义,采用石蜡制片法对多花地宝兰胚囊和胚的发育进行解剖学观察。结果表明,在开花前,多花地宝兰胚珠原基发育缓慢,开花授粉后胚珠原基快速发育成"树状二杈分枝结构",随后在"分枝结构"末端形成孢原细胞,开始胚囊发育。多花地宝兰的胚囊发育属于单孢蓼型胚囊,胚珠具有双层珠被。孢原细胞形成后,经过细胞膨大延长发育形成胚囊母细胞,胚囊母细胞经过减数分裂形成线性四分体,在珠孔端形成1个功能大孢子,功能大孢子经过3次有丝分裂形成8核胚囊。多花地宝兰的胚发育具有藜型和紫苑型两种方式。双受精完成后,多花地宝兰合子进行一次橫裂后形成基细胞和顶细胞;基细胞经过多次分裂形成细胞团,细胞团中的细胞向不同方向膨大延长形成多个胚柄细胞;顶细胞有两种分裂方式,一种是横裂形成藜型胚,一种是纵裂形成紫苑型胚。因此,推测多花地宝兰在兰科植物系统分类学上属于较为原始种。 相似文献
17.
U. K. Schmitz 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1988,75(2):350-356
Summary Reciprocal differences for male sterility, dwarfism and morphological traits have been studied in intra- and interspecific crosses of five Epilobium species. Male sterility occurred in two interspecific hybrids with E. montanum as the male parent while dwarfism has been found to varying degrees in three interspecific crosses with E. watsonni. In contrast to transient differences in plant height and leaf morphology in reciprocal hybrids of the cross between E. hirsutum and E. parviflorum, male sterility and dwarfism persistently occur as reciprocally different traits which may be influenced by determinants of the cytoplasm. The molecular characterization of the plastid DNA of the parental lines and the F1 hybrids indicate that the plastome of male sterile and dwarf plants is identical to that of the female parents. Furthermore, in spite of these developmental disturbances, the expression of plastid genes coding for polypeptides of thylakoid-membrane complexes is unchanged. Thus, it seems unlikely that the genetic compartement of the plastids is responsible for the expression of the male sterile or the dwarfed phenotype. 相似文献
18.
Summary
Amaranthus hypochondriacus ovules are of the crassinucellate type, having several layers of nucellus cells between the micropyle and the embryo sac
through which pollen tubes have to penetrate. The ultrastructural features of the micropylar nucellus cells appear to reflect
cells with high metabolic activity. With the monoclonal antibodies MAC207 and JIM8 (against arabinogalactan proteins) we have
shown that the presence of the two epitopes was different in the gametophytic tissues and embryo sac. The young embryo and
suspensor cells are reactive only to Mab JIM8. The selective presence and localization of these two epitopes was also demonstrated
in the micropylar nucellus cells. The expression of these arabinogalactan proteins in this ovule seems to be closely aligned
with the pathway of the pollen tube, possibly providing directional guides for tube growth inside the ovule. 相似文献
19.
Embryo rescue techniques in Arachis are potentially importantfor recovering interspecific hybrids which have the propensityto abort. Pegs are commonly produced in interspecific crosses,but either they fail to reach the soil because growth is arrested,or pods are produced but embryo development is never re-initiated.Peg tips, with the ovule and embryo, of A. hypogaea L. cv. NC6, were used to determine whether peg tips can be usedas nurse tissue for in vitro culture of embryos. Tissues werecollected 1, 2, 3 and 4 d after self-pollination, after whichpeg meristems were removed from half the pegs, and culturedon five media combinations. Continued reproductive developmentwas observed for embryos cultured at all four collection days;however, the highest frequency of growth was observed in 1-d-oldtissues. Evidence is presented that meristematic activity mayrestrict embryo growth in the 2- to 4-d-old embryos and, oncethe sequence of events is initiated to slow embryo growth, itis not easily reversed in vitro. Achievements of embryo growthto multicellular, globular stages (stages 11 or 12)encourage the development of methods to recover very young embryosthrough tissue-culture techniques. Embryo culture, morphology, interspecific hybridization, Arachis hypogaea, comparative light and scanning electron microscopy, peanuts, groundnuts 相似文献
20.
《Plant science》1988,57(2):159-164
Correlative interactions between the embryo and the ovular tissue in peanut, were studied in vitro. Growth arrest of the embryo in the light was controlled by the ovule. Light perceived by the ovular tissue inhibited embryo growth and the inhibitory effect was diminished by decreasing the amount of ovular tissue remaining attached to the embryo. The suspensor played a major role in the development in vitro of isolated globular and heart-stage but not in the cotyledonary stage embryos. Injury to the suspensor in isolated pro-embryos, inhibited their growth in vitro. Electron microscopy showed disintegrated cells, devoid of starch grains and protein bodies, in nuclear cells surrounding the embryo sac at the micropylar, but not at the chalazal end. This may indicate a role of the suspensor in metabolite absorption by the young embryo. Pro-embryos cultured in a medium with abscisic acid in the dark exhibited a mode of growth arrest similar to that by light. The results suggest that light perceived by the ovular tissue induces the production of substances which diffuse to the embryos and arrest their development. 相似文献