Fig Variety Genetic Testing: Synonyms, What We Know & My Take

The USDA genetically tested its germplasm of Ficus carica. The results can be found in this 2010 publication: https://pmc.ncbi.nlm.nih.gov/articles/PMC2860561/pdf/10709_2010_Article_9442.pdf

In 2018, a set of 23 local varieties from Slovenia and 218 fig accessions from the Californian fig germplasm collection were compared to determine the identity of genotypes and their possible genetic relationships. The results have to be downloaded. See attached.

s10722-018-0634-5.pdf

Download PDF • 1.32MB

I asked AI to summarize these documents to make it more digestible, so in this article, I’m going to take you through its findings and give my own interpretation (in bold). They both have some fascinating realizations. I know you’ll be a better fig grower after reading this. Let’s get started.

The Historic and Genomic Context of Ficus carica

Accurate identification of fig (Ficus carica L.) germplasm is essential for breeding, conservation, and nursery work, yet thousands of years of vegetative propagation and repeated renaming have produced extensive confusion. Figs were first domesticated in the Near East—likely the Jordan Valley over 11,000 years ago—and spread throughout the Mediterranean, North Africa, Europe, and later the Americas through human migration and trade. As cultivars moved across regions and languages, they were repeatedly renamed, creating many synonyms (different names for the same clone), while the loss of historical records and reliance on variable physical traits produced homonyms (the same name applied to genetically different trees). 

For example, the name "Brown Turkey" has become a catch-all term for various brown-fruited figs, obscuring true genetic relationships. 

Fig Tree Synonyms

One of the central and controversial findings of this research was the identification of 32 instances of synonymy, grouping historically distinct cultivars—such as 'Brunswick', 'Rattlesnake', and 'Capitola Long'—into single genetic entities.

This is why I created a list of synonyms. Although not based on genetic testing, but on observation of trialing hundreds of fig varieties.

You can find the synonym list here.

I don’t have an issue with most of the synonyms the studies found. For example, these are well regarded as synonyms, which the studies also list:

1. Bourjassotte Grise & Violet Sepor

2. Beer’s Black & Violette de Bordeaux

3. Paradiso, Ischia Green & Gros Monstreuse

   
   

But there’s a problem: the studies used SSR tests, which only look at a few tiny, quiet parts of the DNA—the parts that don’t really do anything. Because of that, they can’t see mutations that sometimes happen on a single branch of a fig tree (called bud sports), which can make fruit look or taste different. To see those small changes, you need to read the fig’s whole book of DNA, not just a few pages.

The types of mutations that create sports are typically:

1. Single Nucleotide Polymorphisms (SNPs): A change in a single DNA letter (e.g., A to T) in a key gene. For example, a mutation in a regulatory gene controlling anthocyanin production can cause a white grape to turn red.

2. Transposable Element (TE) Insertions: "Jumping genes" that insert themselves into a gene sequence, disrupting its function. This is a common driver of color variation in fruit.

3. Epigenetic Changes: Alterations in DNA methylation that silence or activate genes without changing the underlying sequence.

   
   

So, while the studies show what I would consider a strong list of synonyms, it’s not perfect until whole-genome sequencing is performed.

Lineage Findings

The structural analysis shows that most genetic variation in cultivated figs occurs within groups rather than between them, with AMOVA revealing only 14.7% differentiation among groups—evidence of a shared, relatively recent ancestry and extensive historical gene flow across regions such as Greece, Italy, and Spain. The Neighbor-Joining analysis further identified ten major clusters that did not correspond to traditional morphological categories but instead reflected broad geographic patterns, including a clear separation of Turkmenian figs from the Mediterranean group. Together, these results support the view that while Transcaucasia may represent an early center of origin, the Mediterranean basin functioned as a major genetic mixing hub in the evolution of cultivated figs.

Cluster I.2 is a large group of fig varieties—mostly Common-type figs—that were collected from the United States and many other countries. Their close grouping shows they all come from a fairly recent shared ancestor and have been spread around the world through cuttings rather than seeds. The dominance of Common figs in this cluster is important because it suggests this lineage was repeatedly chosen for being self-fruitful (able to make fruit without pollination) and for other useful traits that growers liked and kept propagating.

Evaluating the Dendrograms

If you compare the dendrograms from both studies, a clear pattern emerges: many of the most popular—and, in my view, genetically superior—fig varieties trace back to a shared ancestral lineage. This helps explain why many Middle Eastern cultivars tend to be lower in fruit quality and why Greece shows a higher frequency of Smyrna types. The data suggest that during Roman times, superior common figs and caprifigs became widely disseminated across Italy, France, Spain, and Portugal. It’s also possible that individuals in these regions were unusually advanced in selecting elite seedlings produced via fig wasp pollination. Another contributing factor may be the reduced degree of hybridization with other Ficus species.

Interestingly, Celeste is closely related to the following varieties. All of these can be found in cluster I.2:

• Coll de Dama

• Becane

• Hardy Chicago

• Olympian (English Brown Turkey)

• Violette de Bordeaux

• Brunswick

These are all known to be hardy varieties.

Here is a full list of hardy fig varieties & breba-producing varieties.

• Cluster G1 & I.1 contains a lot of breba producers and honey figs: Kadota, Dauphine, I258, Desert King, Ischia White, and Alma.

• Cluster G2 contains the tastiest figs in the world: Hivernenca (Verdal Longue), Adriatic (Ischia Green), Coll de Dama, and Black Madeira.

It would be great to find the pollen-producing caprifig parent responsible for each cluster, as we already know how great their offspring are.