Maize B chromosome affects the flowering time

The influence of maize B chromosomes on flowering time was investigated, revealing a tendency for male flowering time to be delayed with an increase in the number of B chromosomes. This research aimed to verify whether the presence of B chromosomes alters the female and male flowering time of Zea mays L. For this purpose, four experiments were carried out, three with inbred lines of the Zapalote Chico race and the last one with the hybrid Cateto x Zapalote Chico. These experiments consisted of classes differing in the number of B chromosomes and were designed in complete randomized blocks, with two replications. In the three experiments conducted with the inbred lines of the Zapalote Chico race, it was observed that B chromosomes had a minimal influence on female flowering. For male flowering time, the statistical analysis results indicated that at least part of the observed variation in the flowering time could be attributed to differences in the number of extranumerary chromosomes. The analysis of the Cateto x Zapalote Chico hybrid confirmed the results observed in the inbred lines of Zapalote Chico race, showing that the influence of B chromosomes on the flowering time in Zea mays L. was more pronounced in the male flowering time. The mechanism by which B chromosomes alter flowering time is still unknown, and more research is needed to better clarify the possible role that the euchromatic and heterochromatic regions of the extranumerary chromosomes may play on the flowering time of Zea mays L.