Ploidy stability in grapevines following long term storage in vitro

A modified method to prepare root tip squashes was used for the routine examination of chromosomes of grapevines developed from in vitro shoot cultures. The results established that adventitious buds obtained by culture of fragmented shoot apices were diploid, and that storage at 9.5 °C of multiple shoot cultures of eight Vitis genotypes for periods up to 12 months did not affect the ploidy level of plants regenerated from them