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Phenolic changes during
in vitro organogenesis of cotton (Gossypium
hirsutum L.) shoot tips
Ibrahim Ilker Ozyigit
Marmara University, Science and Arts Faculty, Department of
Biology, 34722 Goztepe Istanbul/Turkey, E-mail:
ilkozyigit@marmara.edu.tr, Tel.: (+90216) 3487759/1182;
Fax: (+90216) 3478783.
Accepted
10 March, 2008 |
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Browning
and subsequent death of the cultured explants are major
problems for many tissue culture non/hard-adaptive species
and usually depended on the phenolic compounds and the
quantity of total phenols. Many studies, using shoot tips as
explant source indicated various problems such as phenolic
exudation, media discoloration, rooting deficiencies and
explant browning and death. The phenols are synthesized by
the plants and in many tissue culture studies, excreted and
then oxidized phenols effect in vitro proliferation
negatively. In addition, amount of phenolics can be more or
less in different stages of organogenesis due to metabolic
actions. Therefore determination of phenolics and
calculating the amounts of phenols may be another research
area for many tissue culture studies. In this study, total
phenol amounts of shoot tip cultures were evaluated during
in vitro organogenesis of cotton (Gossypium
hirsutum L.). Cotton var. Nazilli 84S was used as
explant source and total phenols of young leaves, shoots and
the MS (Murashige and Skoog) media (for excreted phenols
from explants to medium) were calculated in 7-14-21 and 28
days of culturing period. Seeds were germinated in hormone
free MS media in 7 days. After germination, 7 day old
meristematic shoot tips were dissected out from seedlings
and cultured on MS media, supplemented with 0.1 mg/L Kinetin
(KIN). They were grown at 25oC under fluorescent
light (7500 lx) 16 h light and 8 h dark for 3 weeks.
Singleton-Rossi method based Folin-Ciocaelteu reactive was
used for determination of total phenol amount of the young
plantlets and it was observed that different parts of the
plantlets synthesized more or less amounts of phenolics in
different stages of organogenesis.
Key words:
Cotton, tissue culture, phenolics, browning, organogenesis,
shoot tip.
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