Chromosome structural changes in cultured celery cells

Extensive karyotypic analyses of cultured celery cells were performed to assess variability with respect to the loss or gain of specific chromosome structural types and the nature and extent of chromosomal rearrangements. Among 40 karyotypes, produced from air dried protoplasts of celery suspension cultures, a net loss of long acrocentrics concomitant with a net increase in the number of short acrocentrics was observed as compared to the native karyotype. An average of 1.35 chromosomes per cell in these karyotypes exhibited distinct structural alterations. A technique developed to quantify and qualify actual loss or gain or both of chromosomes was used to determine that 67.5% of the cells were aneuploid, whereas all 40 cells exhibited clear karyotypic changes from the native karyotype. It was concluded that gross chromosome numbers were of little or no value in describing genetic variability at the chromosomal level of organization in this culture.