Cameron Peace, DNA-Informed Breeding Team Leader, Washington State University
What Do You Get If You Cross…
...a stellar parent with an interesting interspecific hybrid, and then self (or backcross) some offspring? With sufficient DNA information on traits, parents, and seedlings, you could predict the outcome. RosBREED is assembling that information to support accurate predictions and efficient mobilization of resources to rapidly achieve intended outcomes. But RosBREED is also encouraging breeders to ask the question in the first place: “What would I get if I crossed…?” To be intrigued with newly revealed possibilities and to take the risk of exploring.
We often say in RosBREED that use of DNA information enhances efficiency, accuracy, speed, and creativity of breeding. What do we mean here by “creativity”? How do breeders like you regard creativity? This article explores the idea of rosaceous crop breeding as a fundamentally creative enterprise and that breeding creativity can be enhanced with DNA-based diagnostic tools and knowledge.
What is Creativity?
Online dictionary definitions include:
“the use of the imagination or original ideas, especially in the production of an artistic work” (Google.com)
"the ability to transcend traditional ideas, rules, patterns, relationships, or the like, and to create meaningful new ideas, forms, methods, interpretations, etc.” (Dictionary.com)
“the ability to make new things or think of new ideas” (Meriam-Webster.com).
The definitions above converge on generation of novel ideas and products. TED Talks provide a wealth of inspiration on the topic of creativity*. During a recent airport layover, I came across a podcast that collected excerpts from some of those enlightening talks. “Applied imagination,” a definition by education and creativity expert, Sir Ken Robinson, captures the concept of novel ideas as well as their physical manifestation. Various other online sources highlight that the novelties produced are also of value and are available in the public domain so that the value can be realized by society. Creativity and breeding surely go hand-in-hand!
What you get when you cross two disparate things is something new. Creativity provides diversity – more opportunity for something different rather than more of the same. Such originality is why the concept of “breeding” is much more than the colloquial meaning of just reproductively propagating. The first step of breeding, crossing, generates novel outcomes by recombining sets of alleles “vertically” along chromosomes and combining pairs of alleles (for diploids) “horizontally” at each locus. Novelty is targeted because it is required for new cultivars to stand out in the marketplace.
The goal of breeding is to release new cultivars that achieve commercial success. The second step of breeding, selecting, evaluates new sets of recombined and combined alleles represented by each new seedling to identify valuable outcomes among them. Done effectively, breeding results in practical, valuable, publicly available products. Therefore, breeding is inherently creative because it seeks to generate valuable novelty.
A huge collation of inspiring TED Talks on the topic of creativity can be found at: www.ted.com/topics/creativity
Exploring the Unknown
Breeding teeters on the edge of the known and unknown. Much of breeding decisions is deterministic, where an action is expected to lead to a targeted outcome. Selection decisions, particularly, are deterministic. For example, selecting seedlings with firm fruit results in an increased probability that new cultivars will have firm fruit in commercial settings. This is about probability and prediction, heritability and genetic potential. Use of DNA information is often touted as a way of enhancing the accuracy of predicting superior performance and enhancing resource efficiency in reaching those predicted outcomes. But the outcome of a breeding decision is often not known or readily predictable. The vast majority of allelic assemblies possible for each crop have never existed, and phenotypes associated with those allelic assemblies have never been observed. Therefore the outcomes are often surprising – and valuable.
Breeders usually revel in the unpredictable outcomes of their efforts. New, unusual parental combinations readily lead to seedlings with previously unforeseen collections of phenotypes. While most breeders regularly make crosses with hoped-for, probable outcomes, many other crosses they make are explorations into the unknown. Similarly, allowing some conventionally undesirable phenotypes to persist rather than be culled at the seedling stage is a prerogative often exercised by breeders. This apparently subjective ability of breeders to achieve valuable novelty – not being able to readily predict the outcome yet having a hunch that it might turn out to be amazing – is what is often referred to as the “art of breeding”. Breeders therefore may approach their endeavors as artists (whether they want to or not!).
“…the art of prediction… for this is where plant breeding is still an art, in trying to assess just what crosses to make in order to move towards a desired outcome.”
-Noel Kingsbury, Hybrid: The History & Science of Plant
Breeding, 2009, The University of Chicago Press
The art of breeding is not in opposition to the science of breeding. Instead, not being artistic as a breeder is proceeding when all outcomes are fully predictable. No experimentation, no research, just continuous advancement in a pre-determined direction. Some breeding programs do lean in this direction, particularly in the private arena. But breeders are not machines. Knowing how everything was going to turn out would be boring! Breeders are scientists (usually), and scientists thrive on ignorance!
“The fuel on which science runs is ignorance. Science is like a hungry furnace that must be fed logs from the forests of ignorance that surround us. In the process, the clearing we call knowledge expands, but the more it expands, the longer its perimeter and the more ignorance comes into view.”
- Matt Ridley, popular science writer and author of “Genome: An
Autobiography of a Species in 23 Chapters” (1999)
Exploring the unknown is risky, where outcomes cannot be predicted and especially where associated costs and potential benefits are large! In fact, for the musician Sting creativity is “the ability to take a risk.” The TED Talks on this topic of creativity, especially interviews with artists, emphasized risk and uncertainty. Author Elizabeth Gilbert says that “fear and creativity are conjoined”. To be creative, we must turn off our conscious self-monitoring and be prepared to be wrong. Not knowing, yet hypothesizing what it will take to develop the desired outcome of a valuable new cultivar, conducting the necessary experiments to test those hypotheses by making the crosses and rigorously evaluating genetic potential for commercial success in the seedlings generated, and making discoveries. Creativity in breeding blends both artistry and science. No wonder it’s so fun!
Making Your Own Luck
“Creativity is a process not an event.” says Sir Ken Robinson in a TED Talk. Creativity does not happen by chance but rather by preparation and diligence. This is why the statement that DNA testing removes “magic” or serendipity in breeding has never been a satisfying explanation to me. You make your own luck. Below is part of the answer given by WSU PhD student Paul Sandefur during his preliminary exam to my question about creativity in breeding. I think he nailed it.
“…when chatting with successful breeders, it is not unusual for them to proclaim that their best selection ever resulted from plain dumb luck. …[M]any of these breeders are simply being humble and in fact their successful cultivars that seemed to come from out of nowhere were the result of well-planned crosses, careful observation, and patience. ... A masterpiece painting may result from unpredicted blending of specific colors and texture, but no masterpiece resulted from dumb luck; masterpieces are targeted artworks that with luck emerged as timeless pieces.”
Which particular genome-wide assemblies of alleles actually appear after crossing, what phenotypes those assemblies yield, and whether a breeder’s favorite assemblies end up as successful new cultivars can be viewed as luck. But those elements of luck can be influenced by a breeder’s active efforts. Serendipity is enhanced – indeed, it can be targeted – with thoughtful, patient, imaginative, inspired work in planning and making powerful crosses, raising and fairly evaluating many offspring, being watchful and adaptive to new opportunities, and convincing others about the superior genetic potential of candidate cultivars. Breeding creativity fuels breeding luck.
And the Survey Says...
I asked numerous breeders what creativity means to them. Excerpts of their replies are below. Some comments were about creating novel ideas and products. Breeders being practical folk, many responses focused on how to achieve those creations. A few reflected on risk, enjoyment in exploration of the unknown, and that breeding creativity is scientific and not only artistic.
“envisioning new insights, processes and products using collective wisdom and knowledge free from constraints of priority”
“new cultivars that are way different from what is available out there”
“novelty – something a consumer would recognize as different in a good way” “innovation”
“a new idea that can be manifested into a recognizable product”
“the interspecific hybridization work of Luther Burbank and Floyd Zaiger immediately come to mind”
“we create our luck – focus and attention!!”
“challenge the norm to pursue an idea”
“germplasm and the variability...the source and inspiration for our creativity”
“application of novel germplasm for novel traits”
“use of novel techniques to improve selection”
“in large populations, multiple environments, and other major factors that increase the chances”
“time spent observing your trees”
“close attention to the plant or trait”
“recognize it when it appears”
“perceive something in a new way which enhances appreciation of its potential”
“To me plant breeding creativity is the vision I have of the perfect variety. All that I do then with research and selection is working toward that ideal. I think that is the reason why each year when I make a crossing design or the first walk through a new selection block is so exciting – it is the anticipation of what could be or what new things I will see. I sort of imagine it is what an artist might feel when creating a piece.”
“I tend to view breeding as an engineering exercise, but with incomplete information. (I don’t believe in) using ‘creativity’ to justify not using latest technologies or recognizing that the phenotype is not necessarily highly correlated with genotype.”
More Magic: Enhancing Creativity with DNA Information
So, how can routine use of DNA information in breeding enable and enhance envisioning, generating, and recognizing valuable novelty, exploring the unknown, and increasing luck?
Here’s a broad suggestion. Use the power of DNA information to enhance efficiency and accuracy for routine, predictable breeding progress, thus ensuring cultivar-generating families achieve baseline trait thresholds and/or developing new cultivars that fill expected market targets with incremental improvements. Then use resource savings for enhancing creativity, to consider and target new opportunities for transformative change.
For example, consider a case where alleles underlying phenotypic variation in a trait of interest are revealed by DNA tests and it is observed that a highly positive-effect allele does not yet appear in homozygosity in the program’s germplasm. DNA information’s window into the allelic components of genetic potential could be used to:
(1) create individuals with targeted novel combinations of existing alleles
→ devise a new spell from a new mix of available ingredients!
As another example, consider a case where 10 elite selections identified in 10,000 seedlings using traditional methods could be more efficiently identified among only 1000 seedlings using DNA information in cross choices and early seedling selection for some traits. The labor, cash, and land savings could be reallocated to:
(2) give more time to think creatively, more liberated from monotonous
operations and the constant demands of thousands of seedlings in recurring
cycles shouting for fair attention
→ allow more time and resources for breeders to work their magic!
(3) introduce novel, hopefully valuable, alleles into the program
→ put more spells in the spell book!
Use of DNA information in at least one breeding operation is already conventional (mainstream) in Rosaceae. Routine use across the spectrum of breeding operations and germplasm levels is becoming more and more the conventional modus operandi. But how each breeding uses DNA information is unconventional. There is a wide margin for creative ways of using these new tools and knowledge – a huge playground!
These answers are purposely vague. It’s up to you how these new tools and knowledge will lead to creative outcomes. Take risks. Indulge your curiosity. Be creative!