Episode 2A: Attack of the Pinot Clones
The following text and photos are contributed by Flying Goat Cellars Ambassador Faye Walker:
Clonal selection is a painstaking, thought-driven process. To produce wines that satisfy a seemingly infinite checklist of desirables, growers watch to see which vines carry specific traits. They then take cuttings from those vines, graft them, and plant them for generations. All subsequent cuttings can be traced to the initial mother vine. That is to say, all share the same DNA.
A Science of Variables
The term cloning is used in many different contexts. In terms of molecular biology, the process of cloning is a technique to produce large quantities of identical DNA molecules. The basic mechanism relies on replication of specific DNA sequences.
When cloning, scientists put a piece of DNA that they are interested in (this is typically a gene with the end goal of generating a protein) into a carrier molecule. Most often, these carriers are small, circular pieces of DNA known as plasmids. Plasmids are commonly found in bacteria and other microscopic organisms. Why are plasmids commonly used? Once plasmids are inside of bacteria, their DNA sequence replicates autonomously--and that includes the inserted DNA of interest. Bacteria will then go on to divide and replicate themselves by binary fission, producing the genetically identical organisms known as clones. Bacteria have their reasons for putting up with plasmids. One of the biggest is for antibiotic resistance. Plasmids possess mechanisms that ensure their survival in the presence of antibiotic drugs, thus keeping their hosts alive.
Annals of Names and Numbers
The relationship between plasmids and bacteria parallels that of clonal selection in the context of grapevines. A grape clone is a cutting taken from an existing grape vine that is grafted onto a rootstock. Once again, cloning is used to produce a plant that is genetically identical to another. More importantly, that first grapevine is chosen due to specific traits that a grower wants to reproduce. This could be fruit quality, berry color--or disease resistance.
There are different clones available for nearly every grape variety, including pinot noir. In fact, pinot noir is renowned for having hundreds of clones. The longstanding history of this variety has enabled researchers to categorically identify the many clones that grew out of different environments over time. The push for clonal selection emerged in Germany during the 1920s. Official Swiss research followed, as three clones--1A, 2A, and 3A--from Wadenswil were imported by Switzerland to UC Davis in 1952. The French research institute for agriculture, food, and the environment then undertook its first official clonal selection of pinot noir clones in 1960. Eleven years later, France officially released its certified pinot noir clones: numbers 111 - 115. Importantly, these clones were proven to be free of the devastating virus phylloxera that had led to a radical shift in the practices and processes of European grapegrowers.
Evolving Aims
For its part, California has taken in European cuttings of pinot noir since the 1800s. California heritage clones represent the historic grapevines that were collected from the Old World, then planted across the golden state. But what happens when the large selection of European clones is not enough? Innovators who dream of better wines can focus on meticulously using viticultural techniques to augment specific traits that are beneficial for the grapes or the vines. For example, take the Martini clone. Developed by winery owner Louis Martini and viticultural pioneer Dr. Harold Olmo at UC Davis, the Martini selections represented virus-free material that originated from Napa plant cuttings.
Switzerland's certified clones, France's Dijon options and California's heritage selections are truly distinct for the manner in which they reflect their environment. Years of observation and propagation have shown the different character, flavor, and allure of each. Number 667 is thought to have tannic and aromatic finesse; 2A is appreciated for its perfume and high yields; and the Swan yields small clusters with concentrated flavors.
Thirsting for More
The diversity of this single varietal makes it a many-roomed mansion well worth exploring. Every time we are submerged in the purples and reds of a favorite pinot, we are taking in a piece of the past. There will always be more to look forward to in the future with this impressionable, resilient and adaptable grape.
Sources and Further Reading
Farrell, S. O and Ranallo, R. T. Experiments in biochemistry: a hands-on approach. Thomson Brooks/Cole, 2006.
Krebiehl, A. A wine geek's guide to pinot noir clones around the world. Wine Enthusiast, May 2023. https://www.wineenthusiast.com/culture/wine/pinot-noir-clones-matter/.
The Prince of Pinot. Understanding pinot noir clonal diversity. PinotFile 11 (12), October 2017.