About the Breeder
The Rutgers University Cranberry Breeding Program is led by Dr. Nicholi Vorsa, a professor in the Department of Plant Biology and Director of the Philip E. Marucci Center for Blueberry & Cranberry Research & Extension, Rutgers University.
Dr. Vorsa became the director of the Philip E. Marucci Center for Blueberry and Cranberry Research in 1991, a position he holds to this day. He possesses numerous patents concerning health attributive qualities of the cranberry, including urinary tract infection prevention and anti-inflammatory characteristics.
A graduate of Rutgers University, Dr. Vorsa subsequently attended The University of Wisconsin, receiving a Masters in 1978 in Breeding and Genetics.
He later returned to Rutgers, where he earned a Doctorate in Breeding and Genetics, in 1985. His cranberry breeding program initiative began that same year. Here, Dr. Vorsa set out to further enhance the yield, fruit quality, and genetic diversity of the cranberry.
The goal of Dr. Vorsa’s breeding program has been to “identify superior parents of diverse genetic background, to produce superior progeny with improved traits.” It was within this aspirational framework that enhanced yield, fruit quality, and genetic diversity of the cranberry were to be achieved.
A Bit of History
Before Rutgers varieties, the cranberry industry relied on only a few productive cultivars, and was dangerously dependent on a narrow genetic base.
For this reason, a critical first step in the breeding program was the establishment of a broad gene pool with which to work, including selections from cultivated beds throughout North America, from the previous USDA breeding program, and from native bogs.
Dr. Vorsa discovered that in many cases, beds of a given ‘variety’ were in fact composed of more than one variety and that varietal misidentification was common.
This problem prompted Dr. Vorsa’s lab to develop the first DNA fingerprinting technique for cranberries, allowing for accurate identification.
Well-known varieties of cranberry, Dr. Vorsa determined, were in fact composed of genetically different individuals. Thus emerged the realization that utilizing existing germplasm plots for breeding, in their genetically impure form, would not lead to the maximum potential of the gene pool at hand.
Over numerous years, Dr Vorsa isolated the most productive strain of the existing commercial varieties. He proceeded to re-establish the germplasm plots from a single vine to ensure genetic purity and superiority of the variety in the plot. In this way, Dr. Vorsa isolated superior parents to produce superior progeny.
New Jersey offers an ideal environment for cranberry breeding due to severe disease pressure and heat stress. These conditions provide the opportunity to identify varieties with higher resistance to disease, scald, and heat stress.
Breeding and Selection
DNA fingerprinting technology enabled individual varieties to be readily distinguished, yet many years of work lie ahead to determine which individuals possessed valuable traits…
By consistently isolating the most productive strain of the existing commercial varieties, Dr. Vorsa achieved superior parents, capable of producing superior progeny.
Once the germplasm was sorted out, many hundreds of controlled crosses were made in the greenhouse, their progeny evaluated in thousands of 5′ x 5′ field plots.
Dr. Vorsa began to discern which varieties had the greatest propensity to develop superior progeny, and these varieties became favored parents.
Traits such as yield, fruit size, percentage rotten fruit, TAcy, fruit chemistry, and plant vigor were all evaluated over multiple years. The best plants were selected and the process was repeated; crosses, evaluation, selection.
Especially promising selections went into larger replicated trials, often at commercial cranberry growers and in several locations.
No other cranberry breeding program in history has made such a patient and extraordinary effort to influence the success of its progeny.