3. Result and discussion
3.1. Lacto-propionic orcein staining
First, for the experiments of chromosome observation at the
metaphase stage in diploid and octoploid strawberry plants, we adopted a method developed by Iwatsubo and Naruhashi (1991)
for diploid strawberries. Fig. 1A shows that many clear
images of diploid plants were obtained using that method.
However, for octoploid plants, there arose various difficulties,
mostly because the root tips of octoploid plants were thicker
and harder than those of the diploid plants: (1) overlapped cells
by insufficient softening treatment, (2) overlapped chromosomes
and unclear imaging attributable to contamination with
cytoplasm, and (3) unclear images of pro-metaphase chromosomes.