Genome size in three multiploid species of Paspalum L.

ECKERS, FABIANA; MARTINEZ E.J.; DAVIÑA JULIO R.; HOJSGAARD, DIEGO; ANA I. HONFI

FOZ DO IGUAZU

Congreso; 2018 INTERNATIONAL CONGRESS OF GENETICS; 2018

INTERNATIONAL FEDERATION OF GENETICS, SOCIEDADE BRASILERA DE GENETICA, ASOCIACION LATINOAMERICANA DE GENETICA

Genome size is the DNA content of the whole chromosome complement, and it is a useful descriptor of plant genetic resources. Paspalum is a genus with relevance for biological studies, due to its great versatility in genetic systems. About 75% of species are polyploids and multiploidspecies are frequent. The aim of this work was to determinate the genome size, and analyze its relation with the ploidy level in three multiploid species of Paspalum. Chromosomes counts were made by conventional staining in Paspalum conjugatum (4x, 6x), P. humboldtianum and P.paucifolium (2x, 4x), all based on x=10. The absolute DNA content was determined by flow cytometry, using propidium iodide for staining and Zea mays CE-777 was used as standard. P. conjugatum 4x showed a 2C-value=2.695 pg and 1Cx-value=0.67 pg, while the 6x cytotypeshowed a 2C-value=2.923 pg and 1Cx-value=0.49 pg. P. humboldtianum 2x has a 2Cvalue=2.688 pg and 1Cx-value=1.34 pg, and the 4x cytotype has a 2C-value=4.597 pg and 1Cxvalue=1.15 pg. P. paucifolium 2x showed a 2C-value=1.977 pg and 1Cx-value=0.99 pg, and 4x cytotype 2C-value=4.031 pg and 1Cx-value=1.01 pg. DNA content 1Cx-value decreases when ploidy increases, in P. conjugatum 6x is 26.87% (p