An improved method for dihaploid production in Nicotiana rustica through anther culture.

The efficiency of dihaploid production from anther culture in N. rustica has been improved by studying the effects of pretreatment temperature, pretreatment duration and initial anther stage on anther response, anther productivity and time to first plantlet production. Pretreatment was most effective on anthers at or around the stage of pollen mitosis. Pollen mitosis stage anthers pretreated at 9 °C for 15 days gave the best results. Both spontaneous and induced dihaploids were obtained. Small plantlets treated with 0.4% colchicine and 2% DMS solution for 5 h produced the maximum number of dihaploids (more than 50%). These considerable improvements in the efficiency of the techniques have made dihaploidy an attractive method for producing inbred lines in N. rustica. This will permit a large scale comparison of dihaploids with more conventional methods of inbreeding such as single seed descent and pedigree breeding.