In Vitro Multiplication of Primary Trisomic Sugarbeets

Seed multiplication is difficult for several of the recently developed sugarbeet primary trisomies. To assure the preservation of these genetic stocks, in vitro shoot multiplication and root induction of eight of the nine trisomic sugarbeet types was inves­ tigated and accomplished. Only type 5 was not suc­ cessfully cloned. Significant differences were found among trisomic types for multiplication rate and weight increase of in vitro clonal cultures. Morphol­ ogy of in vitro plantlets resembled that of trisomics grown from seed. The methods described in this research provide an effective means of maintaining and multiplying most of the sugarbeet primary trisomies.