Refinement of the karyological aspects of Psidium guineense (Swartz, 1788): a comparison with Psidium guajava (Linnaeus, 1753).

Wellington Clarindo,Carlos Roberto Carvalho,Marcia Flores da Silva Ferreira,Amélia Carlos Tuler,Tatiana Carrijo,Anelise Marques

doi:10.3897/compcytogen.v10i1.6462

Abstract

Euploidy plays an important role in the evolution and diversification of Psidium Linnaeus, 1753. However, few data about the nuclear DNA content, chromosome characterization (morphometry and class) and molecular markers have been reported for this genus. In this context, the present study aims to shed light on the genome of Psidium guineense Swartz, 1788, comparing it with Psidium guajava Linnaeus, 1753. Using flow cytometry, the nuclear 2C value of Psidium guineense was 2C = 1.85 picograms (pg), and the karyotype showed 2n = 4x = 44 chromosomes. Thus, Psidium guineense has four chromosome sets, in accordance with the basic chromosome number of Psidium (x = 11). In addition, karyomorphometric analysis revealed morphologically identical chromosome groups in the karyotype of Psidium guineense. The high transferability of microsatellites (98.6%) further corroborates with phylogenetic relationship between Psidium guajava and Psidium guineense. Based on the data regarding nuclear genome size, karyotype morphometry and molecular markers of Psidium guineense and Psidium guajava (2C = 0.95 pg, 2n = 2x = 22 chromosomes), Psidium guineense is a tetraploid species. These data reveal the role of euploidy in the diversification of the genus Psidium.

Highlights

Psidium Linnaeus, 1753 is a genus of Myrtaceae that comprises about 92 species (Govaerts et al 2013), predominantly distributed in the Neotropics
The present study aims to shed light on the genome of Psidium guineense Swartz, 1788, comparing it with Psidium guajava Linnaeus, 1753
Psidium guineense fruits were obtained from indigenous populations occurring in Atlantic Forest remnants located in the Municipalities of Alegre, Itapemirim, Santa Teresa, and Conceição da Barra, all located in Espírito Santo state

Summary

Introduction

Psidium Linnaeus, 1753 is a genus of Myrtaceae that comprises about 92 species (Govaerts et al 2013), predominantly distributed in the Neotropics. The genus is economically important (Rai et al 2010), with Psidium guajava Linnaeus, 1753, Psidium cattleyanum Sabine, 1821 and Psidium guineense Swartz, 1788 being the most relevant commercial species for fruit production and/or source of compounds in the pharmaceutical industry. Of these taxa, P. cattleianum (Costa and Forni-Martins 2007, Costa et al 2008, Souza et al 2015) and P. guajava (Costa and Forni-Martins 2007, Coser et al 2012) are the best-known species with regard to cytogenetic features. The relationship among species that arose from euploidy events is still poorly understood in Psidium

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