Leaves and Seeds as Materials for Flow Cytometric Estimation of the Genome Size of 11 Rosaceae Woody Species Containing DNA-Staining Inhibitors

Iwona Jedrzejczyk,Elwira Sliwinska

doi:10.1155/2010/930895

Abstract

The presence of some secondary metabolites in the cell cytosol can cause a stoichiometric error in the flow cytometric estimation of nuclear DNA content. There is no fully reliable method to completely eliminate the effect of these compounds on nuclei fluorescence, and therefore using plant organs/parts free of staining inhibitors is recommended. Eleven species of Rosaceae with high concentrations of propidium-iodide-staining inhibitors were studied to check the possibility of using seeds instead of leaves for genome size estimation. Despite optimizing the concentration and composition of antioxidants in nuclei-isolation buffer for each species, the effect of cytosolic compounds present in the leaves could not be avoided entirely. None of the seeds of the studied species contained inhibitors, and they produced histograms of good quality. The genome size of the studied species ranged from 1.15 to 3.17 pg/2C; for 10 species the DNA content was estimated for the first time.

Highlights

The Rosaceae family is economically very important because many of the species are cultivated for their fruits (e.g., Malus, Pyrus, Prunus, Fragaria, and Rubus) or have ornamental value (Rosa)
The aim of the present study was to find if the seeds of the 11 Rosaceae woody species containing staining inhibitors in the leaf cytosol are free of such compounds, to compare the quality of the flow cytometry (FCM) histograms of the leaf and seed nuclei, and determine the genome size of those two materials to check their suitability
All the species except Prunus padus (Prunoidae; x = 8) belong to the Spiraeoideae (x = 17) subfamily

Summary

Introduction

The Rosaceae family is economically very important because many of the species are cultivated for their fruits (e.g., Malus, Pyrus, Prunus, Fragaria, and Rubus) or have ornamental value (Rosa). It has been well studied, the systematic position and evolution of many taxa are still not clear. Knowledge of the genome size would be helpful in their classification. Since the chromosomes are small and often numerous, ploidy estimation by chromosome counts is difficult. Microscopic chromosome counting is time-consuming and limited to a few tissues. Flow cytometry (FCM) is a more convenient alternative for establishing the ploidy/genome size of Rosaceae species

Objectives

Methods

Results