14C-labelled Assimilate Distribution in Flowering Maize Plants |
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| Authors: | R T Jasdanwala A A Khan |
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| Institution: | Department of Biological Sciences, Ahmadu Bello University, Zaria, Nigeria |
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| Abstract: | Maize ( Zea mays L.) plants were grown in the field and labelled with 14CO2 at four leaf positions from silking up to maturity. The ear leaf was the most important source of labelled photosynthates to the ear, followed by the first leaf blade above and below the ear. The movement of labelled assimilates from the second leaf blade below the ear was predominantly downwards. The ear became an important sink soon after silking and continued in importance till harvest.
Initially assimilates were partitioned within the ear as husk < cob < grains but at harvest as grains < cob < husk. There was considerable remobilization of assimilates from the husk and stem. Removal of leaves drastically altered the pattern of distribution of labelled photosynthates and the direction of movement was determined by the position of the source leaf blade and the defoliation treatment. Darkening the leaf blades did not much alter the translocation of the labelled photosynthate and increased slightly its proportion to the grains. The removal of the ear severely altered the pattern of distribution of 14C, which was mostly deposited in the stem. |
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| Keywords: | Maize 14C-photosynthates source-sink relationship grain filling period partitioning of assimilates |
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