Intersexual comparison of DNA content by flow cytometry, and chromosome number in four dioeciousChamaedoreapalms from Mexico

Abstract

Flow cytometric analysis of DNA content was performed using nuclei isolated from young leaves of male and female plants of four sympatric Chamaedorea species from Los Tuxtlas, Mexico. Nuclear DNA content distribution showed that more than 90% of leaf nuclei were in the G0/G1 phase of the cell cycle. Nuclei with DNA content higher than 4C were not detected, indicating the absence of endopolyploidy. All four species were diploids. C. tepejilote and C. alternans with 2n = 2x = 32 (x = 16) displayed a 52% variation in 2C DNA content, ranging from 5.95 pg in C. tepejilote to 12.34 pg in C. alternans. C. pinnatifrons and C. ernesti-augusti, with 2n = 2x = 26 (x = 13), had a range in 2C DNA content from 6.67 pg in C. pinnatifrons to 8.26 pg in C. ernesti-augusti (19% variation). DNA content did not vary significantly between male and female plants. On the other hand, we report, for the first time, DNA content in Chamaedorea considering species and sex.