Seasonal changes in sugar beet photosynthesis as affected by exogenous cytokinin N6-(m-hydroxy-benzyl)adenosine.

Čatský J., Pospíšilová J., Kamínek M., Gaudinová A., Pulkrábek J., Zahradníček J.
BIOLOGIA PLANTARUM 38: 511-518, 1996

Klíčová slova: BAP, cytokinin content, chlorophylls, carotenoids, photosynthesis, photorespiration, stomatal conductance
Abstrakt: Abstract Foliar sprays with N6-(m-hydroxybenzyl)adenosine, (mOH)-[9R]BAP, one of the synthetic cytokinins, were applied to field-gown sugar beet twice during the vegetation period: before full canopy closing (/), 6 weeks before harvest (1/) or both. Application of (mOH)[9R]BAP retained high cytokinin content that usually declines prior to harvest. The total content of isoprenoid cytokinins at harvest was 2.6-fold higher in (mOH)[9R]BAP-treated plants as compared to the controls. Treatment I had no significant effect on contents of chlorophylls (Chl) a and b and carotenoids, nor on the rates of net photosynthesis (PN) or photorespiration (RL) , or on CO 2 compensation concentration (F) measured during the whole vegetation period on detached leaves under optimum environmental conditions. Increased values in PN, RE and Chl a and b contents were found in variants//and 1+11 linked with a delay in leaf senescence before harvest. Transpiration rate and stomatal conductances of adaxial and abaxial epidermes were not significantly affected by any treatment.
DOI: 10.1007/BF02890598
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