Occurrence of a mosaic-aneuploid in polyembryonic Norway spruce seed

In this investigation, the chromosome number in the embryos of polyembryonal Picea abies seeds was determined. Polyembryony in seeds of Norway spruce is of rather common occurrence in the northern regions of Scandinavia. The selection of such seeds for experimental purposes can be easily made with the help of x-ray radiography. Among 220 polyembryonal seeds investigated there was one with two embryos. One of the embryos was normal (2n = 24), the other was a mosaic aneuploid with chromosome number ranging from 12 to 24 (Fig. 8). Some other cytological abnormalities were also observed in this embryo. The possibility of getting plants from haploid embryos in polyembryonal seeds is discussed.