Citogenética de especies de Vasconcellea (Caricaceae)

this work aims to know basic aspects of cytogenetics of mountain papayas' or 'papayuelas', vasconcellea species (caricaceae), originated from ecuador and colombia. flower buds were fixed in 3:1 acetic-alcohol solution for 24 hr, transferred to new solution and stored al low temperature. both microsporocytes and pollen grains were stained with 1% acetic carmine. meiosis phases and pollen viability were evaluated to describe chromosome behavior. we found that: 1) all tested species were diploid (2n=2x=18); 2) chromosome number of v. sphaerocarpa, v. longiflora and v. palandensis (2n=18) were by first time reported; 3) asymmetry level of chromosome complements indicated a evolution process in these species; 4) presence of numerous nor in v. sphaerocarpa associated to micronucleoli corroborated its possible hybrid origin; and 5) v. cauliflora (42.98%) and v. cundinamarcensis (47.93%) presented the low percentage of pollen viability.