A Heterochromatic Knob Reducing the Flowering Time in Maize

Maize flowering time is an important agronomic trait, which has been associated with variations in the genome size and heterochromatic knobs content. We integrated three steps to show this association. Firstly, we selected inbred lines varying for heterochromatic knob composition at specific sites in the homozygous state. Then, we produced homozygous and heterozygous hybrids for knobs. Second, we measured the genome size and flowering time for all materials. Knob composition did not affect the genome size and flowering time. Finally, we developed an association study and identified a knob marker on chromosome 9 showing the strongest association with flowering time. Indeed, modelling allele substitution and dominance effects could offer only one heterochromatic knob locus that could affect flowering time, making it earlier rather than the knob composition.

Automated summary

Research has found that maize flowering time is associated with variations in genome size and heterochromatic knob content, although knob composition does not affect genome size and flowering time. A knob marker on chromosome 9 was identified as having the strongest association with flowering time.