Wyniki wyszukiwania

1

Formation of female gametophyte of Larix decidua Mill. in plants from West Ukraine

100%

Fedorowska J., Zhivitsky Z.

Acta Biologica Cracoviensia. Series Botanica. Supplement

|

2000

|

tom 42

|

nr 1

2

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Egg apparatus in sexual and apomictic species of Taraxacum: Structural and immunocytochemical aspects of synergid cells

86%

Musial K., Koscinska-Pajak M.

Acta Biologica Cracoviensia. Series Botanica

|

2013

|

tom 55

|

nr 1

The paper reports a comparative study of the female gametophyte and especially synergid structure in sexual and apomictic dandelions. We analyzed diploid sexually reproducing Taraxacum linearisquameum (2n = 2x = 16) and two triploids, T. alatum and T. udum (2n = 3x =24), with autonomous embryo and endosperm development. There were no observed differences in the organization of the mature megagametophyte between the examined species. Both meiotically reduced and diplosporous embryo sacs showed typical polarity of the egg apparatus cells, together with development of a filiform apparatus in the synergids, but immunocytochemical analyses indicated that microtubules form longitudinal brush-like bundles adjacent to the filiform apparatus in the synergids of the sexual T. linearisquameum. This arrangement of cytoskeletal elements is similar to the configuration described in other amphimictic plants. The synergids of the apomictic T. alatum and T. udum show a uncharacteristic and relatively weak cytoskeleton with no brush-like bundles. We discuss the role of synergids in autonomous apomicts.

3

Ovule, megaspores, and female gametophyte formation in Larix decidua Mill. [Pinaceae]

86%

Slobodnik B., Guttenberger H.

Acta Biologica Cracoviensia. Series Botanica

|

2000

|

tom 42

|

nr 2

Compared to the formation of male generative organs, the development of female sporogenous tissue of the European larch (Larix decidua Mill.) is considerably delayed. The young megaspore mother cell (megasporocyte, MMC) is not observable until late October, a short time before the period of dormancy. In early spring, MMCs become moderately enlarged, with intensive accumulation of starch grains around the nucleus. At the end of the first 10 days of March the MMCs become more rounded in section and the nucleus moves towards the basal part of the cell (near the chalaza). The integument and nucellus become observable at that time and chromosomal strands are visible in the MMC nuclei. Meiosis of MMCs was observed from mid-March to early April. During that period the tip of the integument grows gradually over the nucellus and creates the stigmatic apparatus of the ovule. Instead of the expected tetrads, triads of linearly arranged unequal megaspores were observed in individual ovules at the beginning of pollen shedding. Immediately after meiosis of the MMC, massive growth of the functional chalazal megaspore occurs, along with intensive free-nuclear divisions. The nuclei become located near the megaspore membrane, whereas the whole central part of the developing female gametophyte is filled with an extraordinarily large central vacuole. During intensive growth of the functional megaspore, the innermost layer of the nucellar tapetum gradually disintegrates. This development stage lasts until early May, when the megaspore membrane segregates partially from the nucellar tapetum and the free-nucleate female gametophyte assumes an irregular sac-like shape. The cellular stage of the female gametophyte with typical pyramidal cells at its micropylar end is visible at mid-May. Then the vacuolated (so-called frothy) archegonia gradually forms. The disappearance of vacuoles and the division of the central cell were registered in late May. At the stage of the large female gamete (egg cell) and the small ventral canal cell, the archegonia become fully receptive for fertilization. Our observations indicate that the development of the free-nucleate gametophyte and the formation of cell walls among the nuclei are the most sensitive phases of ovule development in the European larch before fertilization. During these stages, numerous cases of degeneration of the female gametophyte were observed, along with the complete deformation of ovules. The reasons for frequent irregularities are discussed here; the influence of meteorological and nutrient conditions seems especially important.

4

Transcriptional activity of Petunia calreticulin gene (PhCRT) involved in pistil transmitting tract maturation, progamic phase and double fertilization

72%

Suwinska A., Lenartowski R., Lenartowska M.

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology

|

2013

|

tom 94

|

nr 3

5

Immunolocalization of AGO1 in female gametophyte cells of Hyacinthus orientalis L. before and after fertilization

72%

Niedojadlo K., Mehelewska M., Niedojadlo J., Bednarska-Kozakiewicz E.

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology

|

2013

|

tom 94

|

nr 3

6

Ovule, megaspores, and female gametophyte formation in Larix decidua Mill.

72%

Slobodnik B.

Acta Biologica Cracoviensia. Series Botanica. Supplement

|

1999

|

tom 41

|

nr 1

7

On the origin of the ovule: some key events and their impact

72%

Herr J. M.

Acta Biologica Cracoviensia. Series Botanica. Supplement

|

1999

|

tom 41

|

nr 1

8

Is the blue zinc violet [Viola guestphalica Nauenb.] a taxon of hybrid origin? Evidence from embryology

72%

Siuta A., Bozek M., Jedrzejczyk M., Rostanski A., Kuta E.

Acta Biologica Cracoviensia. Series Botanica

|

2005

|

tom 47

|

nr 1

Investigations of reproductive processes of the blue zinc violet (Viola guestphalica Nauenb.) from its natural location in Germany (Blankenrode) and from two sites of introduction in Poland (Wełnowiec zinc spoil and a private garden in Sosnowiec-Ostrowy Górnicze) showed significant disturbances resulting in reduced plant fertility. Pollen viability estimated by acetocarmine staining was relatively low, with 54% viable pollen grains in plants from Wełnowiec and 62% from the garden. Specimens from Blankenrode had 80% viable pollen but the pollen grains differed in size conspicuously. Giant abnormal pollen grains accompanied very small ones. Necrosis affected anthers and pistils, including degeneration of whole anthers and ovules, whole embryo sacs or embryo sac elements, and abortion of embryos. The pathway of female gametophyte and embryo development was normal in 61% of the ovules. Necrosis of somatic tissues and generative cells at different developmental stages was found in 28% of the ovules, and irregular development in 11% of them. As a consequence, embryo viability was reduced to 33%. Embryological data indicated that V. guestphalica is not a well-stabilized genotype. The possible origin of the blue zinc violet is discussed.

9

Anatomical changes in the structure of lupine plants caused by bean yellow mosaic virus

72%

Morozowska M.

Phytopathologia Polonica

|

1993

|

tom 05

10

Development of flower organs in common lilac [Syringa vulgaris L.] cv. Mme Florent Stepman

72%

Jedrzejuk A., Szlachetka W.

Acta Biologica Cracoviensia. Series Botanica

|

2005

|

tom 47

|

nr 2

Studies on the development of common lilac cv. Mme Florent Stepman inflorescence buds and flowers were carried out in 2001-2002 in order to observe the development of flower organs before and after winter dormancy during the following phenological phases: inflorescence bud swelling, inflorescence elongation, flower bud whitening, flower bud swelling and flowering anthesis. The hypogynous, actinomorphic and perfect flower conforms to the general pattern of the Oleaceae. The calyx is four-lobed, and the four-lobed corolla is gamopetalous with a cylindrical basal tube. Two stamens are basally fused with the corolla. The anthers are tetrasporangiate, with a uniseriate epidermis, bilayered endothecium, single middle layer, and secretory, binucleate tapetum. Microspore tetrads are isobilateral and the pollen grains are spherical, three-colpate and two-celled. The ovary is superior and bilocular. Four anatropous, unitegmic and tenuinucellar ovules are formed. The female gametophyte development is Polygonum-type. Flower primordia differentiation starts in midsummer and lasts until autumn. Before entering dormancy, microspore meiosis was discernible in flowers in the lower part of the inflorescence. The ovular primordia differentiate after winter dormancy. During inflorescence bud breaking after winter dormancy, pollen mother cells in anthers and ovule primordia were observed. During inflorescence elongation, pollen mother cell meiosis and microspore tetrads occured in anthers, and the archesporial cell of the megaspores was present in ovules. During flower bud whitening and flower bud breaking, young microspores were observed in anthers, and developing megaspores were visible in ovules. In the last phenological phase, anthers dehisced and the female gametophyte was organized.

11

Changes in distribution of 5' methylcytosine in male and female gametophyte of Hyacinthus orientalis before and after fertilization

58%

Kozlowska M., Niedojadlo K., Bednarska-Kozakiewicz E.

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology

|

2013

|

tom 94

|

nr 3

12

Ovules, female gametophytes and embryos are more sensitive to heavy metal pollution than anthers and pollen of Cardaminopsis arenosa (L.) Hayek (Brassicaceae), a member of calamine flora

58%

Kwiatkowska M., Izmailow R.

Acta Biologica Cracoviensia. Series Botanica

|

2014

|

tom 56

|

nr 1

13

Flower size and developmental stage of Allium cepa L. umbels

58%

Klein M., Korzonek D.

Acta Biologica Cracoviensia. Series Botanica

|

1999

|

tom 41

In onion, seven stages of umbel development were distinguished with regard to the size of umbels, flower buds and developmental stages of male and female gametophytes. At the beginning of blooming, the stage at which buds are most often collected for induction of gynogenesis, flower bud length ranged from 2.0 to 5.0 mm, and the stages from archesporial cell to mature embryo sac were observed in the ovules. Microspores and bicellular pollen grains were observed in the anthers. Flower bud size was not an accurate indicator of pollen development. Buds of the same size but originating from umbels at different developmental stages were characterized by different stages of pollen development.

Ograniczanie wyników

Formation of female gametophyte of Larix decidua Mill. in plants from West Ukraine

Egg apparatus in sexual and apomictic species of Taraxacum: Structural and immunocytochemical aspects of synergid cells

Ovule, megaspores, and female gametophyte formation in Larix decidua Mill. [Pinaceae]

Transcriptional activity of Petunia calreticulin gene (PhCRT) involved in pistil transmitting tract maturation, progamic phase and double fertilization

Immunolocalization of AGO1 in female gametophyte cells of Hyacinthus orientalis L. before and after fertilization

Ovule, megaspores, and female gametophyte formation in Larix decidua Mill.

On the origin of the ovule: some key events and their impact

Is the blue zinc violet [Viola guestphalica Nauenb.] a taxon of hybrid origin? Evidence from embryology

Anatomical changes in the structure of lupine plants caused by bean yellow mosaic virus

Development of flower organs in common lilac [Syringa vulgaris L.] cv. Mme Florent Stepman

Changes in distribution of 5' methylcytosine in male and female gametophyte of Hyacinthus orientalis before and after fertilization

Ovules, female gametophytes and embryos are more sensitive to heavy metal pollution than anthers and pollen of Cardaminopsis arenosa (L.) Hayek (Brassicaceae), a member of calamine flora

Flower size and developmental stage of Allium cepa L. umbels