Light and Electron Microscopic Examination of the Embryo and Endosperm Development in the Natural Tetraploid Trifolium Pratense L.

Algan, Gönül; Bakar, H. Nurhan

doi:10.1080/07929978.1996.10676651

Cited by 9 publications

(9 citation statements)

References 24 publications

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“…The study of this type of barriers requires the knowledge of embryogenesis. Mackiewicz (1965) and more recently Algan and Bakar (1996) have studied the ultrastructure of embryo development and endosperm formation in T. pratense in detail by light and electron microscopes. Kazimierski et al (1972), Kazimierska (1978) and Sawai and Ueda (1987), dealt with the histological observations of the process of embryogenesis after interspecific hybridisation of T. pratense and any other species.…”

Section: Introductionmentioning

confidence: 99%

Identification of barriers to interspecific crosses in the genus Trifolium

2006

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A study of pre-and post-fertilisation barriers after interspecific crosses of diploid and tetraploid Trifolium pratense L. and wild species T. alpestre L., T. medium L. and T. sarosiense Hazsl. was aimed at finding of a promising cross combination for obtaining hybrids. The growth of pollen tubes was arrested in interspecific crosses mainly when T. pratense was at a diploid level. To investigate the post-fertilisation barriers in detail, the hybrid embryo viability was traced by two clearing treatments of immature seeds: (1) using chloral hydrate (which proved to be most appropriate); and (2) a mixture of benzyl benzoate and dibutly phthalate. In interspecific combinations T. pratense (4×) × either T. alpestre or T. sarosiense, enlargement of immature seeds occurred, but no hybrid embryo was traced. Of the wild species used as a male parent for crosses, T. medium was the only exception from the point of view of fertilisation. Globular, heart and the early torpedo stages of hybrid embryos were observed 7 days after pollination (DAP) but only when T. pratense was at a tetraploid level. When T. pratense (2×, 4×) was used as a male parent for interspecific crosses with T. alpestre, T. medium and T. sarosiense, strong defects in various stages of embryogenesis were observed, particularly wrinkled and narrowing embryo sacs caused by an expansion of endothelial cells. We conclude with the following finding: (1) to make crosses only in one direction with T. pratense as a female parent and T. medium as a male; (2) to use tetraploid plants of T. pratense; (3) and to excise hybrid embryos at an early torpedo stage, about 7 DAP.

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Section: Introductionmentioning

confidence: 99%

Identification of barriers to interspecific crosses in the genus Trifolium

2006

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“…Female gametopyte development in the natural tetraploid T. pratense has been examined and some difficulties have been identified observed (Algan and Bakar, 1990). Besides, embryo and endosperm development (Algan and Bakar, 1996) and the ultrastructure of the megagametophyte were investigated in details (Algan and Bakar, 1997a). But there are no reports dealing with the fine structure of fertilisation in this plant.…”

Section: Introductionmentioning

confidence: 99%

Ultrastructural changes of the egg apparatus associated with fertilisation of natural tetraploid Trifolium pratense L. (Fabaceae)

Büyükkartal

2009

Biol. Res.

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The aim of this study is to describe the ultrastructural changes of the egg apparatus associated with fertilisation of the natural tetraploid Trifolium pratense. The pollen tube enters one of the synergids through the filliform apparatus from the micropyle. Before the entry of the pollen tube into the embryo sac, one of the synergids begins to degenerate, as indicated by increased electron density and a loss of volume. This cell serves as the site of entry for the pollen tube. Following fertilization, the vacuolar organisation in the zygote changes; in addition to the large micropylar vacuole, there are several small vacuoles of varying size. Ribosomal concentration increases significantly after fertilisation. In T. pratense, ultrastructural changes between the egg cell and zygote stages are noticeable. Several marked changes occur in the egg cell because of fertilisation. The zygote cell contains ribosomes has many mitochondria, plastids, lipids, vacuoles. After fertilization, most of the food reserves are located in the integument in the form of starch. The zygote shows ultrastructural changes when compared to the egg cell and appears to be metabolically active.

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“…An even greater degree of developmental variability is evident among free nuclear endosperms when comparisons are made with higher eudicot taxa, represented here by legumes (Fabaceae) (Yeung and Cavey, 1988;Dute and Peterson, 1992;Chamberlin, Horner, and Palmer, 1994;XuHan and Van Lammeren, 1994;Algan and Bakar, 1996), Stellaria (Caryophyllaceae) (Newcomb and Fowke, 1973), and Helianthus (Asteraceae) (Newcomb, 1973) (Fig. 47).…”

Section: Evolutionary Implications: Multiple Origins Of Free Nuclear mentioning

confidence: 95%

“…Multiple origins of free nuclear endosperm development among dicots and monocots were also predicted by Dahlgren Olson, 1981;Johri, Ambegaokar, and Srivastava, 1992. c Chitralekha and Bhandari, 1993;XuHan and Van Lammeren, 1993. d Newcomb, 1973 Yeung and Cavey, 1988;Chamberlin, 1994;XuHan and Van Lammeren, 1994;Algan andBakar, 1996. f Newcomb, 1973;Johri, Ambegaokar, and Srivastava, 1992. g Fineran, Wild, and Ingerfeld, 1981;Van Lammeren, 1988;Olsen, Potter, and Kalla, 1992;Olsen, Brown, and Lemmon, 1995;Olsen, 1996. (1991).…”

Section: Evolutionary Implications: Multiple Origins Of Free Nuclear mentioning

confidence: 99%

“…In general, these higher eudicot taxa have less extensive free nuclear development prior to cellularization than the free nuclear basal eudicots, although there is variability in this feature. Cellularization begins when fewer than ten free nuclei are present in Helianthus (Newcomb, 1973), whereas many free nuclei are produced before walls form in Stellaria (Newcomb and Fowke, 1973) and legumes (Algan and Bakar, 1996). Endosperm cell wall initiation in the higher eudicots appears to occur at a relatively advanced embryo stage, but this feature also varies among the higher eudicots.…”

Section: Evolutionary Implications: Multiple Origins Of Free Nuclear mentioning

confidence: 99%

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A developmental and evolutionary analysis of embryology in Platanus (platanaceae), abasal eudicot

Floyd

Lerner

Friedman

1999

American J of Botany

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The Platanaceae are an early derived eudicot lineage and therefore occupy a key position for understanding reproductive character diversification associated with the early evolutionary radiation of flowering plants. We conducted an embryological study of Platanus racemosa in order to provide critical data on defining angiosperm reproductive characters for this important group. Female gametophyte development is monosporic. Embryogenesis occurs in a series of stages including zygote elongation and division, development of a linear proembryo, formation of the embryo proper, histogenesis, organogenesis, and growth. Endosperm development is a complex process that includes four distinct phases: free nuclear proliferation, cellularization of the chalazal zone, centripetal cellularization of the micropylar zone, and cellular differentiation and growth. Only the outer endosperm layer persists at seed maturity. Our findings differ significantly from previously published reports for Platanus, in which endosperm development was described as ab initio cellular. A comparison of endosperm development in Platanus with several closely and distantly related free nuclear taxa reveals considerable developmental variability, consistent with a hypothesis of multiple origins of free nuclear endosperm in angiosperms. Our analysis indicates that much remains to be learned about embryology in basal angiosperms. Additional developmental and comparative studies will likely reveal critical insights into the early evolution of flowering plants.

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Light and Electron Microscopic Examination of the Embryo and Endosperm Development in the Natural Tetraploid Trifolium Pratense L.

Cited by 9 publications

References 24 publications

Identification of barriers to interspecific crosses in the genus Trifolium

Identification of barriers to interspecific crosses in the genus Trifolium

Ultrastructural changes of the egg apparatus associated with fertilisation of natural tetraploid Trifolium pratense L. (Fabaceae)

A developmental and evolutionary analysis of embryology in Platanus (platanaceae), abasal eudicot

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