Citogenética de genotipos de uchuva, Physalis peruviana L., y Physalis floridana Rydb., con respuesta diferencial a Fusarium oxysporum

Vascular wilt caused by the fungus Fusarium oxysporum is considered the main constraint of cape gooseberry, Physalis peruviana, production in Colombia. P. peruviana and P. floridana genotypes with differential resistance responses against F. oxysporum have been identified previously. In the present study, the genotypes were evaluated in order to complement the knowledge of cytogenetics diversity in Physalis and to design hybridization strategies to support breeding of cape gooseberry crop. The chromosome number in mitotic dividing cells from root-tips of tissue culture plantlets was determined, from which the average mitotic hour was estimated at 12:00 hours for P. peruviana and 10:00 for P. floridana. Chromosomic complements of 2n = 4x = 48 and 2n = 2x = 24 were found for each one of the two species. Additionally, flow cytometry analyses detected variation within P. peruviana with a nuclear DNA content of 2.33 pg for the 2n = 24 genotype and variations ranged from 5.77 to 8.12 pg for 2n = 48 genotypes. In P. floridana DNA content was 2.29 pg in the 2n = 24 genotype and 4.03 pg in the 2n = 48 genotype. There was a significant effect (α = 0.01) of the number of chromosomes on nuclear DNA content for the two species