Abstract

A series of experiments were carried out to investigate the effects of ethyl methane sulfonate (EMS) as an in vitro mutation mutagen using the anther-derived embryos of loquat (Eriobotrya japonica Lindl) which had been newly developed in the laboratory for the first time in the world. The results showed that EMS treatment caused changes in vitality and conformation of the anther-derived embryos. All EMS treatments employed in the study resulted in lower vitality to various extents depending on the EMS concentration and duration. The death rate of loquat anther-derived embryos was over 50% while the EMS concentration ranged from 0.1 to 0.9% and the exposure time of treatment was 0.5, 1 and 2 h, respectively. Maximal survival rate (46.2%) was obtained in the treatment of 0.3% EMS for 0.5 h and minimal survival rate (2%) was obtained in the treatment of 0.7% EMS for 2 h. The induction ability of secondary embryos decreased after the EMS treatment. Both the maximal percentage (46.2%) of embryos producing new embryos and the maximal number (5.4) of newly formed embryos per embryo producing new embryos were obtained in the treatment of 0.3% EMS for 0.5 h. Minimal percentage (2.8%) of embryos producing new embryos was obtained in the treatment of 0.7% EMS for 2 h. Minimal number (2.75) of newly formed embryos per embryo producing new embryos was obtained in the treatment of 0.9% EMS for 2 h. EMS treatment caused more morphological malformations in the secondary anther-derived embryos. Changes were detected with RAPD amplification profiles in the secondary anther-derived embryos from EMS treatment. There were diversities on the RAPD profiles in the EMS treated embryos, and 0.3% EMS for 2 h was the most effective in causing changes detected by RAPD in all treatments.

Key words: In vitro mutation, ethyl methane sulfonate (EMS), anther-derived embryos, Eriobotrya japonica Lindl.