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Cytological features of various microspore derivatives appearing during culture of isolated maize microspores

100%

Goralski G., Rozier F., Matthys-Rochon E., Przywara L.

Acta Biologica Cracoviensia. Series Botanica

2005

tom 47

nr 1

Microspore derivatives occurring in culture of maize microspores were studied by light and electron microscopy. The cultures showed a high degree of heterogeneity throughout the whole period of cultivation. Several types of androgenic structures at different developmental stages were observed, indicating a high level of asynchrony among microspores following the androgenic pathway. During the first 5 to 7 days of culture, multicellular structures developed inside the exine. At later stages of culture the developing microspores ruptured the pollen wall and formed structures variable in cellular characteristics. Three main types were distinguished: (i) one-domain structures consisting of small or large cells only; (ii) two-domain structures with large and small cells, the domains differing in size and cellular characteristics; (iii) callus-like structures. The two-domain structures seem to resemble zygotic proembryos which also contain two different parts, the suspensor and the apical region. The observed variability is most likely related to differences in gene activity during the inductive stage of androgenesis and the genetic properties of the microspores themselves, rather than to the conditions of in vitro culture.

First embryogenic stages of Citrus microspore-derived embryos

84%

Ramirez C., Chiancone B., Testillano P. S., Garcia-Fojeda B., Germana M. A., Risueno M. C.

Acta Biologica Cracoviensia. Series Botanica

2003

tom 45

nr 1

This work is the first characterization at cellular and subcellular level of the main cellular events occurring in the first stages of microspore embryogenesis. Microspore embryogenesis was induced in two varieties of Citrus Clementina (Nules and Monreal). The results showed that one of the most responsive stages for embryogenesis was the vacuolate microspore. Microscopic analysis revealed specific features of the young proembryos still surrounded by the exine: large nuclei, clear areas in the cytoplasm, starch accumulation, and an increase in the thickness of the wall under the exine. Immunogold labelling with JIM 5 antibody showed a high amount of non-esterified pectins in the surrounding cell wall. After exine rupture, different cell types were detected in late proembryos. As embryogenesis proceeded, the normal pattern of development was observed, including heart-shape, torpedo and cotyledonar embryos.

Ograniczanie wyników

2 Acta Biologica Cracoviensia. Series Botanica

1 Chiancone B.

1 Garcia-Fojeda B.

1 Germana M. A.

1 Goralski G.

1 Matthys-Rochon E.

1 Przywara L.

1 Ramirez C.

1 Risueno M. C.

1 Rozier F.

1 Testillano P. S.

1 2005

1 2003

Wyniki wyszukiwania

Cytological features of various microspore derivatives appearing during culture of isolated maize microspores

First embryogenic stages of Citrus microspore-derived embryos