Variation in the Chromosome number of cultured shoot tip of Vitis spp. by p-fluorophenylalanine treatment.

Abstract

The effect of p-fluorophenylalanine (PFP) on the induction of variations in the chromosome number was investigated in cultured shoot tips of Vitis clones, including triploid and tetraploid cultivars and interspecific hybrids. A higher concentration (400 μM) of PFP inhibited the growth of the shoot tips. The abnormal mitoses and the variations in the chromosome number including the induction of haploid and aneuploid cells were observed in the shoot tip cells treated with PFP. Variations in the chromosome number were also observed in the root tip cells of regenerated plants after PFP treatment. However, most of cells with abnormal chromosome number co-existed with normal cells. The average perc6ntage of the anormal cells was about 1.0% among total observed cells of all the clones examined. In most of the cases the abnormal chromosome number observed in the roots was euploids, regardless of the ploidy level of the clones examined. There were fewer aneuploids in root cells than in the shoot tip cells. In all the experiments, two variants (about 0.3% of the plants checked) had large sectors with reduced numbers of chromosomes in the shoots. One was a triploid-tetraploid variant from the tetraploid cultivar Kyoho, and the other was a diploid-triploid variant from the triploid clone KC-1.