“That’s not Vanilla planifolia”

This is the unfortunate news that I’ve had to share with a few collaborators in different countries over the last few months. From small-scale growers to big companies, it seems that no one is immune to growing, buying, or investing in the wrong vanilla species. This is especially true for V. x tahitensis that seems to be a common term used around the world for anything that is similar to, but not exactly the same as, a standard V. planifolia. How is there so much confusion surrounding vanilla? Well, most people can tell the difference between an orange and a lemon, but how many can correctly differentiate these trees just by the leaves and branches? The risk to the vanilla industry comes when spending money on something with lower quality than V. planifolia, or labeling something as if it was V. planifolia and, surprise (!), it’s actually not. It gets even more complicated when hybrids are prevalent. How do we prevent wasting capital and effort on the wrong vanilla species? Well, it depends.

In order to grow vanilla, you must first obtain vanilla vines. You could go online and buy a vanilla vine on Ebay. You could get a vine from a neighbor who says it’s V. planifolia. You could also go into a natural area, find a vine, call it V. planifolia, and then sell it to your neighbor (don’t do this in Florida, it’s illegal in at least two ways). Most likely these vines will be V. planifolia or some variant thereof. With due diligence done, you have V. planifolia at ~70% confidence (aka “Don’t bet the farm”). Is 70% good enough? The vanilla flowers pictured at the head of this article look like V. planifolia, but are actually a V. planifolia hybrid with yields about a tenth of the standard V. planifolia. That’s a costly mistake for being comfortable at 70%. Surely we can do better.

We do have a simple method that relies on single gene sequencing. Basically, it’s a few hundred DNA nucleotides (high school biology anyone?) and it mostly tells you what species you mother was. So, it’s a maternity test. This means for a few dollars we can increase our confidence to ~90%, because we know that at least the mother of the tested plant was the correct species. Unfortunately, these simple maternity tests can’t differentiate hybrids, including V. x tahitensis, from pure V. planifolia. This is shown in the provided graphic under the “Simple genetic tree” header. You can think of the genetic tree like a family tree. Closely related things are found together on the same “branches” (see V. planifolia branch highlighted in blue).

Confidence at 90% still includes a unacceptable level of risk. So, we developed a new genetic test that can now (relatively) cheaply scan around 5,000 DNA markers to identify a plant’s mother, father, and sometimes even grandparents. This DNA test is like a molecular fingerprint. This is shown in the graphic under “Thorough genetic tree” and the “STRUCTURE plot”. The tree works the same way as the simple tree, but it’s much more accurate. The colored bars for the STRUCTURE plot run horizontally and indicate DNA patterns. So, V. planifolia is shown as light blue, V. pompona is green, and so forth. Hybrids are easily identified because they have two colors (or more) in the colored bars. Can you find the plant that has a blue and green bar? Yes, this is a hybrid between V. planifolia and V. pompona. It would also be found incorrectly placed in the blue V. planifolia group of the Simple genetic tree. With the new test, you’ve increased confidence in your ability to correctly identify a species or a hybrid to >99% (nothing is really ever 100% to a biologist). You are also now ready for a new career as a molecular geneticist. Congratulations.

             What does this mean? Well, we’re learning that there are many more hybrids and misclassified vanilla vines out there than we thought. This can result in painfully bad news at first, but it’s probably better to be sure you have the right plant species before you invest time and money into a vanillery (this is like a winery, but for vanilla). At the same time, we can generate great confidence in species assignment when plants are very, very small. This way there aren’t any unpleasant surprises 3-5 years down the road. This also means that we can confirm that someone is selling product from the advertised species and is compliant with the vanilla standard of identity. Risk reduced.

You can read more about this in our publication. https://www.nature.com/articles/s41598-019-40144-1