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The development of the female gametophyte in Fragaria x ananassa Duch. cv. Selva

100%

Dziadczyk E., Domaciuk M., Nowak M., Szczuka E., Bednara J.

Acta Biologica Cracoviensia. Series Botanica

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2011

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tom 53

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nr 2

Megasporogenesis and female gametophyte development were investigated in ovules of the everbearing strawberry Fragaria × ananassa Duch. cv. Selva. Observations of thin sections revealed that ovule development starts from the formation of a nucellus and coincides in time with the beginning of receptacle overgrowth. The most characteristic feature during nucellus differentiation is the formation of a multicellular archesporium, beginning from at least two cells. Analysis of female gametophyte development indicated that in addition to the meiotic mode, female gametophytes develop by an apomeiotic mode of Antennaria type. Asynchronous development of female gametophytes of different origin occurs. The mature, eight-nucleate, seven-celled female gametophyte of meiotic origin is cylindrical and slightly curved. It occupies the central part of the nucellus. The egg apparatus, consisting of an egg cell and two synergids, is formed in the micropylar part of the female gametophyte; the opposite chalazal pole is occupied by antipodal cells. Besides the ovule in which only one seven-celled female gametophyte finally develops, ovules with a different number of cells were observed to initiate female gametophyte development. Some ovules contain a nucellus with a tetrad of linearly arranged megaspores surrounded by enlarged cells, each of which has the potential to develop into an apomictic female gametophyte. After degeneration of some post-meiotic cells or developmentally advanced female gametophytes, some of the chalazal cells initiated female gametophyte development.

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Development and functioning features of archesporium in species of Sanguisorbeae tribe [Rosaceae]

84%

Kolesnyk O. B.

Acta Biologica Cracoviensia. Series Botanica. Supplement

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1999

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tom 41

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nr 1

3

Ovule and seed development in Vaccinium myrtillus L. [Ericaceae]

59%

Anisimova G. M., Shamrov I. I.

Acta Biologica Cracoviensia. Series Botanica

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2000

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tom 42

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nr 1

Ovule and seed morphogenesis in Vaccinium myrtillus was studied here for the first time. The gynaeceum is paracarpous. The ovules are developed at sutural-angular placentae. Periclinal divisions of the subepidermal cells of the placenta usually precede formation of the ovular primordia. The ovules are ana-campylotropous, medionucellate, unitegmic, leptochalazal and sessile. The initials and dynamics of different ovule structures were determined. The chalazal zone of the nucellus transforms into the postamento-podium. The integument is of dermal origin, with a typical endothelium. The ovule has a hypostase, which is initiated with the beginning of ovular primordium differentiation. It is cup-shaped in the mature ovule and consists of 2-3 layers. Their cell walls are not lignified. The nucellus, integumental parenchyma, endothelium and hypostase do not persist in the mature seed. The latter is exotestal. The embryo sac develops according to the Polygonum type. The endosperm is cellular, with micropylar and chalazal haustoria. The mature embryo is large and well differentiated into organs.

Ograniczanie wyników

2 Acta Biologica Cracoviensia. Series Botanica

1 Acta Biologica Cracoviensia. Series Botanica. Supplement

1 Anisimova G. M.

1 Bednara J.

1 Domaciuk M.

1 Dziadczyk E.

1 Kolesnyk O. B.

1 Nowak M.

1 Shamrov I. I.

1 Szczuka E.

1 2011

1 2000

1 1999

The development of the female gametophyte in Fragaria x ananassa Duch. cv. Selva

Development and functioning features of archesporium in species of Sanguisorbeae tribe [Rosaceae]

Ovule and seed development in Vaccinium myrtillus L. [Ericaceae]