BREEDING SYSTEMS IN COIX LACRYMA-JOBI POPULATIONS

Six populations of Coix lacryma-jobi with distinct characters were stu died to evaluate the presence of autonomous apomixis and pseudogamy, a nd to determine its implications and effects in the calculations of th e rate of breeding. For this reason, two types of genetic markers were used - morphological markers and isozymatic markers. The results show that autonomous apomixis does not seem to occur in these populations. Further experiments are necessary to prove the presence of pseudogamy in one of the populations. The rate of natural outcrossing in the gra in types Rosario, Rosadlay and I-47 fluctuated around 35.9% using esti mates based on isozymatic markers. The rate of natural outcrossing was 37.4% in the Adlay population using morphological markers. A populati on composed of tall individuals, named Tailandia, which has a greater vegetative mass and fewer grains, presented a high level of natural ou tcrossing at 72.8%. This information is important for many reasons, su ch as: 1) guiding sampling strategies of genetic material, 2) in the o rganization and upkeep of germplasm banks, and 3) for plant breeding p rograms.