Researchers have taken their berry breeding down to some of the smallest components of nature possible.

They are using microsatellites—short, repetitive, non-coding DNA sequences that can be used to compare species and varieties.

The bits of DNA carry genetic maps for traits, such as agronomic quality and nutritional components.

By identifying how these bits repeat themselves, they can differentiate cultivars.

In a study partially supported by the Northwest Center for Small Fruit Research, Nahla Bassil, a plant geneticist with the Agricultural Research Service in Corvallis, Ore., has worked with colleagues in Beltsville, Md., to generate several DNA sequences for blueberries.

The scientists developed microsatellite genetic markers from those DNA sequences, and established that these markers could be used to identify not only blueberry varieties, but cranberry and rhododendron varieties as well.

A different type of DNA-based marker had previously been developed for cranberries by plant pathologist James Polashock, formerly with Rutgers University and now with the ARS Plant Sciences Institute in Beltsville. Bassil and Polashock are collaborating to identify the strengths and weaknesses of each marker system for use in identifying cranberry varieties.

In related work, Rowland and Bassil are collaborating on an international effort to develop more genetic markers for blueberries that will be used to improve traits, such as cold hardiness and fruit quality.