Increasing anther culture efficiency in rice (Oryza sativa L.) using anthers from ratooned plants

Anther culture response for the variety Taipei-309 was compared using anthers of ratooned and non-ratooned plants. Anthers were plated onto N6 liquid media with 0, 2, 5, and 10 mg l(-1) ABA, respectively. After 5 days in culture, the media were removed and N6 medium without ABA was added. A higher number of pre-mitotic P-pollen grains were observed in anthers from ratooned plants. A significant synergistic effect was found between anthers from ratooned plants/ABA concentrations and the increase in embryogenic-like structures (ELS) induction and green plant regeneration efficiency. The highest frequency of anthers producing ELS was found in N6 medium (6% Sucrose and 2 mg l(-1) 2,4-D) with 5 and 10 mg l(-1) ABA for anthers derived from ratooned plants. Mean green plant regeneration efficiencies were raised from 24.2 to 42% (non-ratooned), and from 30 to 70%, (ratooned donor plants) using a combination of 10 mg l(-1) ABA in induction media, and MS with 2 mg l(-1) BAP, 1 mg l(-1) NAA, 2 mg l(-1) kinetin and 0.45% agarose. The highest number of green shoots per ELS were obtained from ratooned-derived anthers (up to 82). The use of ratooned plants in anther culture, its importance and relative advantages are also discussed.