Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 21

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
The effects of different concentrations of copper ions (Cu2+ in the form of CuS04 x 5H20) on in vivo cucumber (Cucumis sativus L. ‘Edinstvo’) seedlings as well as on in vitro hypocotyl-derived callus were considered. Callus induction from hypocotyls was more prolific than from roots or cotyledons. Thus, callus obtained from hypocotyls of 7-day-old cucumber plants was cultured for 5 weeks on Murashige and Skoog medium containing 4 mg dm'3 2,4-D + 1 mg dm'3 BA supplemented with 0.01 mM, 0.1 mM or 1.0 mM of Cu2+. Biochemical indices related to oxidative stress were assessed. Cu2+ at 0.01 mM stimulated callus induction but 1.0 mM Cu2+negatively affected callus formation and growth. LPO intensity was significantly lower than the control at all concentrations of Cu2+ but significantly higher than the control in plants exposed to 0.01 or 0.1 mM Cu2+. A similar trend was observed for the generation of the superoxide radical in both callus and plantlets. Superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APOX) activity increased in both callus and plantlets, but the level of increase in these antioxidant enzyme systems depended on the Cu2+ concentration. Cu2+ ions had a stronger (i.e., more negative) influence on oxidative stress in cucumber seedlings than on cucumber callus.
The use of flower tissue for the in vitro propagation of chrysanthemum (Chrysanthemum 9 grandiflorum (Ramat.) Kitam.), an ornamental plant, provides a specific and precious explant type for organogenesis (regeneration of adventitious shoots/roots) or somatic embryogenesis. This is of great importance for the breeding of this species. In vitro culture of flower tissue can lead to the separation of chimera components to obtain stable mutants. Moreover, regenerants derived from ray (ligulate) or disc (tubular) florets may present somaclonal variation. The ability to then regenerate such plant material can result in the production of plants with novel flower colour, modified architecture or other positive attributes, even more so after the application of physical mutagens such as gamma radiation. Although in vitro flowering is a rare phenomenon in chrysanthemum, the notion that it could be possible would allow for the formation of flower material that could serve as in vitro-disinfected material without the need to introduce explants, and possible contamination, from the ex vivo milieu. Regeneration protocols from flower tissue would allow for breeding using such tissues to be advanced while the process of in vitro flowering could also be better understood. This review provides an up-todate understanding of what is known in this field of research.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.