Flow cytometric analysis using SYBR Green I for genome size estimation in coffee

Area of Science:

• Plant molecular biology
• Cytometry and cell analysis

Background:

• Flow cytometry is standard for plant genome size measurement using propidium iodide.
• Secondary metabolites in plants like coffee can cause genome size estimation errors with propidium iodide.

Purpose of the Study:

• To evaluate SYBR Green I as an alternative fluorochrome for plant nuclear DNA staining.
• To compare the accuracy and efficiency of SYBR Green I against propidium iodide in Coffea species.

Main Methods:

• Nuclear DNA was stained using SYBR Green I and propidium iodide in Coffea canephora and Coffea arabica.
• Flow cytometry was employed to measure genome size and analyze G(0)/G(1) peak variations.

Main Results:

• SYBR Green I and propidium iodide yielded statistically identical mean genome sizes.
• SYBR Green I showed significantly lower coefficient variations in G(0)/G(1) peaks (1.57-2.85%) compared to propidium iodide (2.75-4.80%).

Conclusions:

• SYBR Green I is a suitable fluorochrome for stoichiometric nuclear DNA staining in plant flow cytometry.
• SYBR Green I offers advantages including reduced errors in DNA content quantification, faster staining, high affinity, and lower mutagenicity than propidium iodide.