Factors Affecting Haploid Plant Regeneration from Maize Anther Culture

Abstract

Anthers from CH-13 Zea mays plants were cultured in order to optimize the pretreatment and culture conditions. A cold pretreatment of 6 to 9 days at 9 °C was found to be optimal while 9 % sucrose in the culture medium was better than 3, 6, 12 or 15 %. Adding plant hormones or activated charcoal did not increase the response but orienting the anthers on edge rather than flat on the medium stimulated embryoid formation. Under optimal pretreatment and medium condition, 12 % of the cultured anthers produced embryoids. In no case was callus formed directly from the pollen or anthers. Of 80 anther-derived embryoids transferred onto regeneration medium, 90 % produced plants, of which 60 % were phenotypically normal. Root tip chromosome counts of 53 plants showed that 51 were haploid and two were diploid. From a total of 43 normal plants regenerated soon after the anthers were cultured, 2 were albino and 41 were green. Callus capable of forming plants for periods longer than one year could be induced from the small embryo structures on a culture medium containing dicamba.