Abstract: The contents of nuclear DNA in different ploidy kiwifruit cultivars were measured by flow cytometry, a simple, rapid method for the identification of kiwifruits ploidy was established. Diploid “Red Sun” Kiwi was used as control, ‘81-5’, ‘Wan Chui’ Kiwi as material, the ploidy was identified by screening the optimal leaf area, improving dissociation liquid formulations, improving membrane mesh and the number of filters, increasing the number of centrifugation. The results showed that open conditions of field cultivation, the early exhibition leaf under the stem tip is the best part of ploidy identification; twice centrifugation; dissociation solution 2% PVP-30; 500 mesh membrane filtration twice can effectively resolve the blocking of tube, effectively remove impurities and obtain a clear peak sample peak. The optimized technology enables the simultaneous determination of two or more kiwifruit mixed samples.

Key words: flow cytometer, kiwifruit, ploidy identification, peak