Jiji GeorgeAnitha Karun2015-01-062015-01-062011Current Science, Vol. 100, No. 6, 25 March 2011http://hdl.handle.net/123456789/6113The palmyrah palms are slow-growing dioecious perennials and have no distinguishing features to identify the sex until flowering. The palm commences flowering only after 12–15 years of maturity. The seed sex ratio (primary sex ratio) was estimated by germinating seeds and growing seedlings under favourable conditions with minimal mortality until flowering. Early sex determination was done to assess the seed sex ratio of one-, two- and three-seeded fruits with a male-specific random amplified polymorphic DNA marker. The seed sex ratio (M : F) of seedlings raised from one-, two- and three-seeded fruits were 57 : 43, 35 : 65 and 61 : 39 respectively. There was no correlation between the number of seeds in a fruit and sex of the seedlings raised from them. The overall percentage of M : F was 52 : 48, which was almost 1 : 1 ratio. While comparing the sex ratio of one-, two- and three-seeded fruits individually, the sex-ratio of two-seeded fruits was 0.350 with probability 0.263. This indicated a female-biased sex ratio (M : F) in two-seeded fruits (35 : 65).enApocolonpyrenesrandom amplified polymorphic DNAsecondary sex ratioseed sex ratioArticle