| Autor: |
Haccius, Barbara, Reichert, Hans |
| Zdroj: |
Planta: An International Journal of Plant Biology; 1964, Vol. 62 Issue 4, p355-372, 18p |
| Abstrakt: |
Young undifferentiated embryos of Eranthis hiemalis were treated with x-rays (1000-4000 r) and their further development was observed. In most of the 4000 r-group the division-activity is completely and irreversibly arrested, but the cell image remains unchanged. The embryos treated with doses between 1000 and 2000 r are also severely damaged, this time undergoing radical disorganization of the tissue, due to degeneration and necrosis. In these embryos small cell groups or even single cells are able to regain their mitotic potency. Meristematic centers ('embryoids') arise and develop into normal or sometimes misformed viable adventive embryos. This restitution takes place only in x-rayed embryos whose cell coherence is heavily disturbed, a condition which is absent not only after exposure to low (<1000 r) but also to high (4000 r) x-ray doses. It is concluded that the somatic cells of young embryos are totipotent when released from the as yet unknown correlative influences of their environment. Since the adventive embryos are more exposed to developmental disturbances than the zygotic ones, they show a higher percentage of morphological anomalies. Therefore in the future it will be necessary, when dealing with the so-called x-ray induced cotyledonary anomalies, to distinguish between true x-ray damage of the original embryo and indirect teratogenic effects in the case of adventive embryony. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
Full text from SpringerLink