Establishment of multiple shoot clumps from maize (Zea mays L.) and regeneration of herbicide-resistant transgenic plantlets.

A kind of quick, efficient and season-free inducing embryoid and multiple shoot clumps system from shoot tip meristems that derived from elite inbreds of maize was established. The herbicide-resistant gene als (coding Acetolactate synthase) isolated from a mutant of Arabidopsis thaliana was transferred to tissue pieces of maize multiple shoot clumps by microprojectile bombardment. Herbicide-resistant tissue and regenerants were obtained through selections with herbicide chlorsulfuron. PCR analysis and Southern blot hybridization indicated that gene als has been transferred to some regenerants. The test of spraying chlorsulfuron displayed that the transgenic plantlets and R(1) plants had favorable herbicide-resistant trait. We have established a new genotype-free system of maize which could rapidly and efficiently produce large quantities of transgenic plantlets.