Expression Levels of Flowering Time Genes ( CONZ1 , GIGZ1A , GIGZ1B , FKF1A , and FKF1B ) in Seedlings under Long-Day Conditions Differentiates Early and Late Zea mays L. Lines

Phenophase durations, including the timing of flowering and ripeness, were characterized in 20 inbred lines of the maize Zea mays L. Expression of key flowering initiation genes ( CONZ1 , GIGZ1a , GIGZ1b , ZmFKF1a , and ZmFKF1b ) under long-photoperiod conditions was studied in seedlings of six maize lines that differed in ripeness time. Significantly lower transcription levels of all of the five genes were found in early-ripening lines compared with late-ripening lines. Similar expression patterns were observed for the GIGZ1a and GIGZ1b paralogous genes, while ZmFKF1a significantly predominated in expression over its paralog ZmFKF1b .