RFLP ANALYSIS TO IDENTIFY PUTATIVE CHROMOSOMAL REGIONS INVOLVED IN THE ANTHER CULTURE RESPONSE AND CALLUS FORMATION OF MAIZE

RFLP analysis was performed with anther culture-derived callus lines developed from the maize F1 hybrids Pa91 x FR16 (PF), H99 x Pa91 (HP) and H99 x FR16 (HF). Relatively evenly spaced RFLP markers were selected to cover the maize genome with 52, 58 and 35 RFLP markers for the PF, HP and HF callus lines, respectively. The results from populations PF and HP combined with limited information from HF showed that six chromosomal regions on chromosomes 1, 2 (two regions), 3, 6 and 8 appear to be associated with the formation of embryo-like structures (ELSs) from microspores or the subsequent formation of regenerable callus from the ELSs. Regions at the end of the long arm of chromosome 2 and on the long arm of chromosome 8 appear to be associated with ELS formation, and the other regions appear to be associated with either ELS or regenerable callus formation or both. Certain regions that we have identified are the same as those found in other studies to be important for friable, embryogenic callus formation (chromosomes 1 and 3 and near the centromere of 2) and for ESL formation (chromosomes 1 and 3). This study has provided evidence for the genetic basis of the maize anther culture response and callus formation.