Tissue Culture Regeneration of Plants in Zea diploperennis, a Close Relative of Corn

Abstract

High frequency and reliable plant regeneration from somatic cells of Zea mays is the key step in allowing the tools of soma-clonal variation, somatic cell hybridization, and recombinant DNA to be used in the development of improved breeding lines. This communication describes high frequency plant regeneration from somatic stem donor tissue of field-grown Zea diploperennis. Reliable plant regeneration has now been achieved in a perennial diploid relative of corn (Zea diploperennis), which, like perennials in general, is highly tillered. This species is being used in our maize improvement program as a source of germplasm for the unique trait of high tillering and its associated capacity for plantlet regeneration. After 3–4 subcultures of cultured somatic tissues on a primary medium, small callus fragments are transferred to secondary medium devoid of the auxin, 2,4-D. After a few days, numerous shoots regenerate and develop into normal plantlets which are then separated and transferred to a tertiary medium for root development. The selection of somaclonal variants from cultured somatic cells of interspecific hybrids between corn and teosinte holds promise for the synthesis of breeding lines suited for the development of improved corn varieties.