Abstract: Various methods for ploidy determination were investigated and evaluated in cucumber. The results indicated that chromosome counting was the most reliable and precise method , however , it was cumbersome and required skilled cytological techniques; The chromocenter size , heterochromatin number , guard cell chloroplast number and certain plant morphological characteristics have close corelationships with ploidy levels , and are simple and practical methods for ploidy determination but with some shortages.

Key words: Cucumber (Cucumis sativus L. ), Ploidy determination