The USDA Cranberry Genetics and Genomics Lab (CGGL) at the University of Wisconsin-Madison group began compiling genetic fingerprinting data in 2011. Since then, they have identified the consensus genetic profiles and the parentages of many cranberry cultivars. Based on this research, they provided the first free and reliable cranberry DNA fingerprinting method available to Wisconsin growers (Fajardo et al. 2013).  

This work was particularly important and difficult because of the practice of sharing or selling cranberry propagule among growers and the long-lived perennial nature of cranberries, both of which lend themselves for producing genetic contamination overtime. A survey was conducted in 2011 where Wisconsin cranberry growers sent their samples with their cultivar labels. The CGGL then compiled all the samples with different cultivars names and started sorting the different genetic profiles and cultivar names, and hybrid parentages. Since then, thousands and thousands of samples have been submitted from Wisconsin growers. Additionally, data from growers from other states and internationally has been gathered. More recently, the three major cranberry diversity collections have been analyzed such as the USDA National Clonal Repository cranberry collection (2018), the Rutgers University cranberry collection (2020), and the Dubay Wisconsin cranberry collection (2022).

The CGGL has used all the data compiled over time to study cranberry cultivated diversity; data is continually being gathered from growers., and there is still much to learn in the realm of cranberry genetic fingerprinting. The information has been used to create a database of cranberry genetic profiles that includes the true-to-type genotype for most major named cultivars. The database is always evolving and changing as new information becomes available. Additionally, the database is being used to store every incidence of a unique genetic profile produced in growers’ fields, and some of these genetic profiles do not match any known cultivar or parentage. These unknown genotypes probably arose from chance seedlings from natural crosses or self-pollination of cultivated cranberries or even from wild cranberries.¹ When growers submit their samples, they provide trait information, for example the barren-berry trait, and the database stores trait information for future assessment of troublesome genetic invasions being reported by growers through their submission of sample for genetic analysis.   

This progressive approach of refining the data has resulted in some changes in the genetic profiles labels overtime. For example, one the most prevalent barren-berry genetic profiles identified in Wisconsin in the early years of the research was originally labeled as Crowely. This label originated in grower submissions and remained in place based on consensus analysis; in other words, many of the samples submitted by growers of this genetic profile had the name Crowley. Additionally, there was one sample in the national cranberry collection with the label Crowley which had the same genetic profile.  Therefore, the name Crowley was adopted and reported back to growers for this barren-berry cultivar. However, recent data from the three cranberry collections analyzed has shed new light on the parentage and true identity of this barren-berry genotype. Based on newly available parentage data, this genetic profile could not be Crowley (McFarlin x Prolific) based on the newly acquired McFarlin genetic profile. Although the genetic profile of Prolific has not been identified, the McFarlin genetic profile clearly shows that this genetic profile is indeed not Crowley. Therefore, a new search of all databases was conducted and based on another genetic hit with the national cranberry collection, the possible name (“Perry Red”) was identified for this barren-berry genotype. At this time, the Perry Red name has been identified for this genotype, and there is no indication that this will change in the future since all the major cranberry collections have been analyzed. This genotype has been found to be a prevalent barren-berry invader genotype in both Wisconsin and Massachusetts.

But where did barren-berry Perry Red come from?

All the historic information that we have is that Perry Red was a wild selection from Massachusetts, and it was selected in 1888 (Dana, 1983). According to Dana, “Perry Red was named by J. Perry and planted in Marion, Mass. The medium-sized fruit (80-100 cup) ripens and colors well in storage. The berry is round with a flat calyx end and is covered with heavy bloom. Coarse vines support tall up-rights with large dark green leaves that are capable of producing good crops.” Based on this information it is likely that this wild selection was once grown commercially and was a productive genotype that became contaminated and was lost to the current barren-berry genetic profile we see today. Then, it was passed along among growers and eventually was dropped from cultivation due to its unproductivity. We can conclude that the barren-berry cultivar we have been referring to as Perry Red is likely different from the originally named Perry Red, but the originally named Perry Red has been lost to time and will not reappear, so though the name “Perry Red” was originally used to describe a different cultivar, both cultivars do not ‘exist’ at the same time today, so it was decided to adopt the name Perry Red to describe this barren-berry cultivar.

Now, what do we know about Crowley? Quoting Vorsa and Zalapa, 2019 on the development of Crowley:

The first breeding and selection cycle was initiated in 1929 by the United States Department of Agriculture (USDA) and the New Jersey and Massachusetts Agricultural Experiment Stations in response to a devastating disease, “false‐blossom,” caused by a phytoplasma […] the first populations were field planted in 1.5 × 1.5 m plots in 1934 at Whitesbog, […]. Breeding populations from additional crosses were planted in 1937 and 1943. […] From 30 crosses made between 18 native selections a total of 8,692 seedlings were evaluated […] The majority of the parents were [native selections from Massachusetts, Michigan, and Wisconsin]. Selection of progeny from the 1934 planting was initiated in 1938 and carried out over three years through 1940. Of the over 8,000 seedling plots, 1,800 plots that produced at least a pint for two to three consecutive years were further evaluated. The berries were hand‐harvested and placed into storage for 2–3 months. The selection criteria included average yield, percent sound berries post‐storage and “general appearance.” Since only the seedlings producing a minimum quantity of fruit were evaluated, it is likely that indirect selection for establishment (stolon) vigor, precocious fruiting, upright production, fruit set, and fruit size took place. From the Whitesbog planting, 40 selections were initially selected for further testing. In 1945 an additional 182 seedlings were selected for further testing. The selections were further evaluated in a “second test” in New Jersey, Massachusetts, and Wisconsin. From this first breeding and selection cycle, six named varieties were released. The cultivars that were initially released in 1950 from the 40 “numbered” selections in 1940 were ‘Stevens’, ‘Beckwith’, and ‘Wilcox’. Subsequently ‘Pilgrim’, ‘Bergman’, and ‘Franklin’ were released in 1961 (Dana 1983). A second round of selections were made, […] which were not officially named except for [Willapa Red] and ‘Crowley’.

Figure 1 shows a Principal Coordinate Analysis (PCoA), which is a method commonly used to simplify large amounts of cranberry genetic data into visually informative charts. Looking at the chart, the genetic profiles of differences and similarities are seen in a spatial arrangement. Genetic profiles that are more distant from each other are more genetically dissimilar and ones that are closer are more genetically similar (clones match exact positions in the chart). An example of a parentage analysis is illustrated with Crimson Queen, HyRed, and Sundance (all progeny of a Ben Lear x Stevens cross), and they expectedly cluster in a spatially similar locations between their parents Ben Lear and Stevens. Again, this type of clustering or grouping analysis is a simplification, but it allows the visualization of large data sets, which is useful for growers and geneticists while examining variety purity data and genetic relationships. 

When Dr. Zalapa’s group began this fingerprinting research, they found that a cultivar name might appear at several different points on the chart. Crowley was one example—appeared in two places on Figure 1–with one genetic fingerprint landing close to the parental McFarlin. The most likely reason for this observation is that some samples had been mis-identified and mis-labeled. The ”Crowley” near McFarlin is a fruiting cultivar. The “Crowley” (now labeled Perry Red) near Bugle Mashpee in Figure 1. is non-fruiting.  If Crowley was selected from one of 1,800 hybrids that produced at least 1 pint of fruit in a 5’x5’ plot two years in a row—and we have two “spots” on in Figure 1. named Crowley—it is more likely that the fruiting cultivar (left dot) is the “true” Crowley; and the non-fruiting cultivar is likely to be a contaminant which was incorrectly labeled, now labeled Perry Red (Figure 1). Additionally, new data provided in Figure 2. shows the genetic profiles of the of the true-to-type Crowley, McFarlin, and the barren-berry Perry Red. It is clear from the genetic profiles that the barren berry Perry Red cultivar is not related to McFarlin or Crowley because it does not share at least half of the genetic profiles, one number in each marker.

Since the barren-berry Perry Red cultivar shows up commonly in growers’ plantings in both WI and MA, it is likely that this contamination occurred early in the east and was spread through propagation in more recently planted beds in Wisconsin. A current study of Massachusetts contaminated beds labeled as Stevens and Crowley supports this conclusion as the same barren-berry genotype has been identified. This would explain the mislabeling associated with the name Crowley and prevalence of this contaminant in Stevens beds in both states. Dr. Zalapa noted that, since the unfruiting “Crowley” contaminant was already known to many growers, “it would be annoying to withdraw the cultivar’s name and replace it with just “unknown 12””—so his team identified the most likely named cultivar first associated in history with this genetic fingerprint. This is Perry Red (1888) based on an accession with that name stored at the USDA National Clonal Repository cranberry collection.

In conclusion, there used to be a cultivar named Perry Red which has been lost to time. Now we are using the name “Perry Red” for this barren-berry cultivar, based on the traits that growers have submitted. In the future, other prevalent barren-berry cultivars may be identified, and if they are prevalent enough to warrant a name, to avoid the question Crowley or Perry Red?, they will be labeled, barren-berry 1, 2, 3, etc.

As we continue the process of fingerprinting cultivars—those produced, those newly bred, and those contaminating our production beds—we are likely to find more information that will highlight areas where we had had misunderstandings in the past. How exciting it is to gain new understanding!

References:

Dana, M.N. 1983. Cranberry cultivar list. Fruit Var. J 37:88–95.

Fajardo, D., J. Morales, H. Zhu, S. Steffan, R. Harbut, N. Bassil, K. Hummer, J. Polashock, N. Vorsa, and J. Zalapa. 2013. Discrimination of American cranberry cultivars and assessment of clonal heterogeneity using microsatellite markers. Plant Molecular Biology Reporter 31(2):264–271. doi: 10.1007/s11105-012-0497-4.

Matusinec D., A. Maule, E. Wiesman, A. Atucha, M. Jyostna Devi, and J. Zalapa (2022) The New Cranberry Wisconsin Research Station: Renovation Priorities of a ‘Stevens’ Cranberry Marsh Based on Visual Mapping, Genetic Testing, and Yield Data, International Journal of Fruit Science, 22:1, 121-132, DOI: 10.1080/15538362.2021.2014016 https://www.tandfonline.com/doi/full/10.1080/15538362.2021.2014016

Vorsa, N., and J. Zalapa. 2019. Domestication, genetics, and genomics of the American Cranberry. Plant Breeding Reviews 43:279–310.

This article was posted in Cranberry and tagged Allison Jonjak, Cranberries, cranberry genetic profiles, crowley, Juan Zalapa, perry red.