Anther culture and Hordeum bulbosum-derived barley doubled haploids: mutations and methylation.

Anther culture and Hordeum bulbosum-derived doubled haploid (DH) lines of barley (Hordeum vulgare L.) were analyzed for RFLP and RAPD polymorphisms. Polymorphisms were not detected in the anther culture- or H. bulbosum-derived DH lines among 273 RFLP and 89 polymerase chain reaction (PCR)-amplified DNA fragments assayed. It was calculated that base substitution or small deletion/insertion mutations had not been induced among 401,640 bp screened. Large deletion/insertion mutations were not observed among 33 Mb screened. Polymorphisms were observed when DNA was digested with the methylation-sensitive restriction enzymes HpaII and MspI: these RFLPs originated primarily from the anther culture-derived doubled haploids. The data indicate that heritable DNA methylation changes had occurred during DH production, particularly with the anther culture method.