Chronic water-deficit stress may increase meiotic recombination in maize.

Meiosis and recombination lead to gametes with novel combinations of genes as key processes in evolution and plant breeding. Numerous extrinsic factors have been reported to affect meiotic recombination of plants. The goal of this research was to identify simple, low-cost, and effective treatments that affect recombination in maize (Zea mays L.). The treatments, water-deficit stress and defoliation, were separately applied to two F1-generation genotypes, B73/Mo17 and Mo17/H99. The F1 plants were backcrossed to an inbred line to produce the backcross populations that were genotyped at microsatellite loci on chromosomes 1 and 10. Overall, 1271 crossovers were observed in the progeny of the water-stressed plants while 1092 were observed in the progeny of the non-stressed plants. The water-deficit treatment may have increased the rates of recombination in both F1 genotypes while the defoliation treatment was ineffective.