Influence of soil acidity and environment on the frequency and localization of chiasmata in maize (Zea mays L.)

In order to assess the influence of soil acidity and environment on the frequency and localization of chiasmata, seven maize genotypes, four of them heterozygous and three homozygous, were cultivated ill the field and in a greenhouse on acid and corrected soil. The analyses demonstrated a differential behavior among genotypes with respect to interaction with environment and level of soil acidity. For most genotypes there was an increase in the frequency of chiasmata when they were grown on corrected soil both in the field and in the greenhouse. Under all conditions tested the heterozygous genotypes presented higher chiasma frequencies than did the homozygous genotypes. These results show that the rate of genetic recombination of a population, estimated by chiasma frequency, may be increased when the material is cultivated in soil of good fertility.