Flow cytometry is being recognized as a powerful tool in the areas of plant science and agronomy. Flow cytometry techniques are allowing plant breeders to develop and evaluate new plant specimens more quickly and accurately. Measuring DNA content or ploidy in plant cells is one of the most powerful applications of flow cytometry and is now widely used across plant research sectors.

Measuring Ploidy

New plant cultivars are evaluated for phenotypic features, such as growth rate and fruit yields, but genotypic screens are also critical in the early phases of evaluation. Ploidy is defined as the number of chromosome sets in a cell. Animal cells are typically diploid, having two sets of chromosomes (except for gametes which are haploid). In contrast, many plants are polyploid, and this seemingly excessive genetic content is considered to offer evolutionary benefits. Ploidy can be measured by flow cytometry by staining and quantifying nuclear DNA content (C-value). Nuclei are isolated from plant cells, seeds or callus and stained with DNA-binding fluorochromes, and C-values can be measured over a large dynamic range. These C-values can then be used to estimate genome sizes, level of ploidy, and replication stage.

Applications

Ploidy data is useful to basic plant research on novel plant species, but has many industrial applications, including characterization of parent and progeny plants during plant breeding, and screening of seeds during crosses between two different parent plants.

Beyond Ploidy

Flow cytometry can also be used to evaluate the subcellular content of plant cells, including chlorophyll content and characterization of the cell wall. New techniques and protocols are also being developed as more reagents are developed for plant-based flow cytometry applications. Flow cytometry is becoming a valuable tool for advancing plant science research.