Use of In Vitro Kernel Culture to Study Maize Nitrogen and Carbohydrate Metabolism.

Grain yield in maize is the result of a genotype's response to environmental conditions and agronomic management. However, whether in a field, greenhouse, or growth chamber, plant-to-plant variation exists within the same genotype, necessitating large amounts of plants and growth area to determine a metabolic response to a change in growth conditions or fertilizer supply. Additionally, because of whole-plant interactions in the supply of nutrients to kernels, it is difficult to study assimilate or temperature effects on the growth of kernels.

Relationship of source and sink in determining kernel composition of maize.

The relative role of the maternal source and the filial sink in controlling the composition of maize (Zea mays L.) kernels is unclear and may be influenced by the genotype and the N supply. The objective of this study was to determine the influence of assimilate supply from the vegetative source and utilization of assimilates by the grain sink on the final composition of maize kernels.

Amino acid metabolism in maize earshoots. Implications for assimilate preconditioning and nitrogen signaling.

Nitrogen (N) is an essential requirement for kernel growth in maize (Zea mays); however, little is known about how N assimilates are metabolized in young earshoots during seed development. The objective of this study was to assess amino acid metabolism in cob and spikelet tissues during the critical 2 weeks following silking. Two maize hybrids were grown in the field for 2 years at two levels of supplemental N fertilizer (0 and 168 kg N/ha).