02080naa a2200229 a 450000100080000000500110000800800410001910000230006024500860008326000090016930000100017852014530018865000120164165000150165365300240166865300160169270000200170870000260172870000220175470000180177677300560179420646172023-01-30       2016    bl uuuu     u00u1 u    #d1 aCHIAVEGATTO, R. B.  aKaryotype asymmetry in Cynodon Rich. (Poaceae) accessions.h[electronic resource]  c2016  a12 p.  aAbstract Cynodon is a genus of plants with forage potential that has attracted the interest of breeders. These species have high morphological variability in a large number of varieties and cytotypes, hampering identification. This study aimed to determine the karyotype asymmetry index among accessions of Cynodon to discriminate between them. Karyotype symmetry was based on three estimates, which were compared. The basic number for the genus is x = 9. The results of the chromosome count and DNA quantification, respectively, were as follows: two diploid accessions (2n = 2x = 18 and 1.08 ± 0.094 to 1.17 ± 0.036 pg DNA and ± standard deviation), one triploid accession (2n = 3x = 27 and 1.63 ± 0.017 pg DNA), four tetraploid accessions (2n = 4x = 36 and 1.88 ± 0.069 to 2.10 ± 0.07 pg DNA), and one pentaploid accession (2n = 5x = 45 and 2.55 ± 0.098 pg DNA). C. incompletus var. hirsutus had the longest total length of the haploid lot (29.05 µm), with chromosomes that ranged from 1.7 to 6.2 µm in length. On the basis of the karyotype asymmetry indices, the accessions were divided into two groups: 1) C. dactylon var. dactylon, C. transvaalensis, C. dactylon var. polevansii, three accessions of Cynodon sp, and C. nlemfuensis; and 2) C. incompletus var. hirsutus. This is the first description of tetraploidy in C. transvaalensis. The karyotypic data facilitated a determination of the degree of proximity between the accessions.  aCynodon  apolyploidy  aChromosome symmetry  aDNA content1 aPAULA, C. M. P.1 aSOUZA SOBRINHO, F. de1 aBENITES, F. R. G.1 aTECHIO, V. H.  tGenetics and Molecular Researchgv. 15, n. 4, 2016.