Abstract:In order to understand the variation of mango (Mangifera indica L.) germplasms in Yunnan, the genome size of 35 germplasms was determined by flow cytometry and their variation was analyzed. The results showed that the mean genome size among the 35 germplasms was 0.445110 pg and 0.4353177×109 bp, which the minimum one (0.434567 pg, 0.4250060×109 bp) was YSM-44 from Jinghong, and the maximum one (0.458679 pg, 0.44485881×109 bp) was YSM-25 from Honghe. The genome size variation of wild germplasms was the largest (CV=1.65%), followed by semi-wild germplasms (CV=1.26%), semi-cultivated germplasms (CV=1.21%) and cultivated germplasms (CV=0.11%). The bryophytes had similar genome size to mango, which is consistent with the "C-value paradox" theory. Therefore, flow cytometry method could accurately and fastly measure genome size of mango, and the genetic variation in wild, semi-wild and semi-cultivated germplasms was rich, these could be used for mango breeding.