Cytotaxonomy of Tripogandra diuretica and T. glandulosa (Commelinaceae) from NE Argentina

GRABIELE, M.; HONFI, A. I.; DAVIÑA J. R.

PLANT BIOSYSTEMS

TAYLOR & FRANCIS LTD

Lugar: Roma; Año: 2010

1126-3504

Karyotype features and microsporogenesis of T. diuretica (Mart.) Handlos and T. glandulosa (Seub.) Rohw. from fifteen NE Argentina accesions are analyzed via classical cytogenetics, CMA/DA/DAPI and Ag-NOR. The karyotype of T. glandulosa (2n=2x=16; 2m+6sm+8st) is bimodal (A2=0.37; R=2.65) and assymetrical (A1=0.63; i=26.06; r>2=0.88) (3B-Stebbins) with a genome size of 33.28 µm; two pairs are satellited, CMA+ and NOR-actives. Another four CMA+ loci and DAPI+ universal centromeric heterochromatin occur. Microsporogenesis is normal (pollen viability short stamens=97.8%; large=96.7%), meiotic behaviour is regular and chromosomes pairs as 8II. The karyotype of T. diuretica (2n=8x=64; 8m+24sm+32st) is bimodal (A2=0.27; R=2.54) and assymetrical (A1=0.60; i=27.32; r>2=0.88) (3B-Stebbins), additionally, two pairs are satellited. Microsporogenesis is normal (short stamens=77.8%; large=68.5%), except for micronuclei and low pollen viability in some accessions. Meiotic behaviour is regular with 32II, acting as a cytological diploid, however, the arrangement of the haploid karyotype suggests that T. diuretica, which also exhibits a reduction of the genome size (18.58 ìm), constitutes an auto-octoploid taxa. Additionally, both species share cytological features common to karyotype orthoselection.