Nuclear ADN content and ploidy level in apomitic bufflegrass genotypes

Abstract

Buffelgrass [Pennisetum ciliare (L.) Link syn. Cenchrus ciliaris L.] is a polyploid fodder grass that has mostly apomictic reproduction. The wide genetic and cytological diversity present in the species indicates that the active field collection of the IFRGV - INTA might contain individuals with different ploidy levels. The aims of this work were to determine the nuclear DNA content and ploidy level of an introduced apomictic germplasm of buffelgrass. Cytological studies showed different ploidy levels in the germplasm. Genetic resources include tetraploid (2n = 4x = 36) and aneuploid (2n = 43 and 44) individuals. The 10 materials that exhibited 2C values ranging between 3.04 and 3.17 pg were tetraploid cytotypes. The values of the four aneuploid individuals with 43 chromosomes ranged between 3.83 and 3.86 pg, whereas aneuploid individual with 44 chromosomes had 2C value of 3.94 pg. Number of chromosomes and nuclear DNA content were correlated. In addition, a model equation was obtained, which might be used to estimate DNA ploidy value in buffelgrass genotypes.