Scheldorf Image.png

Provided; Elizabeth Nelson
Provided; Elizabeth Nelson

PhD Candidate Promotes Diverse Orchard

by Melia D. Matthews

Apples for sale in grocery stores today have been bred for sweetness, size, color, and shelf life. They are products of selective breeding carried out by growers for centuries. For all their apparent variety, however, domesticated apples aren’t particularly diverse from a genetic standpoint. Fuji and Honeycrisp, Red Delicious and Granny Smith—all domesticated varieties belong to a single species. Many are closely related to each other, and they are not particularly resistant to disease. Fire blight and apple scab have worried North American apple growers since domesticated apples were introduced. Now, erratic weather patterns in a rapidly changing climate are putting additional stress on domesticated apple trees.

Have you ever tasted a wild apple? Unlike the domesticated apple, there are several species of wild apples, and most are likely to set your teeth on edge. But wild apples have evolved through natural selection over millions of years, and many are better equipped than domesticated varieties to survive in less-than-ideal conditions.

Understanding the desirable traits of wild and domesticated apples is the business of Andrew Scheldorf (he/they), a fifth-year doctoral student in horticulture. They work in the fruit physiology and climate adaptation lab in Geneva, directed by Jason Londo, School of Integrative Plant Science, Horticulture, where they study an apple tree population created by crossing the domesticated apple, Malus × domestica, with a wild species that originated in western Asia, Malus prunifolia.

The crossbred population displays a wide range of traits, some of which are prized by growers. “I look at a number of different traits in this population, including fruit size, fruit mass, sugar, acidity, tree architecture, phenolic compounds, total tannins, disease resistance, vigor, and storage ability,” Scheldorf says.

Wild Resilience

Scheldorf noticed that roughly half of the apples harvested from the population held up well during extended storage. But the other half lost soundness, becoming soft and mushy. Intrigued, Scheldorf used genotypic information and the fruit’s storage time to conduct a Genome-Wide Association Study (GWAS). Based on the results, they believe they have identified a gene that affects the shelf life of apples.

“This is a prime case in understanding what novel and useful traits can come from wild species.”

Breeders have long thought that crossing wild-type apples with the common domesticated apple would yield small, discolored, unpalatable fruit that would be of no interest to the consumer. Even if the fruit were sturdier and the trees more disease resistant, growers believed the fruit would not be marketable.

Scheldorf’s work upends conventional wisdom. “My population has shown that, with careful selection of the wild species parent—and some patience—you can get commercially viable fruit with some of the genetically and physiologically useful traits from the wild species,” they say. Their findings could be valuable both to geneticists and apple breeders. “This is a prime case in understanding what novel and useful traits can come from wild species,” Scheldorf says.

Making Space for Alternative Viewpoints

Scheldorf identifies as a member of the queer community. As they have sought to improve domesticated apples by drawing on the genetic diversity in wild apples, they have also felt the lack of diversity in plant science, and in science, technology, engineering, and mathematics (STEM) fields in general. They suggest that the way wild-type apples have been discounted can be seen as emblematic of how people from historically excluded communities have for centuries been shunted aside, forgotten, or disallowed in science, math, and engineering fields.

“I started to see an interesting parallel between wild apple species and historically excluded communities in STEM and academia more broadly. While both offer alternative solutions to major issues and lessons to make things more just and equitable, they both have been largely excluded from the spotlight,” Scheldorf says. “I saw how people were treating me and others in the queer community differently. In STEM we are taught to not insert ourselves into our research, don’t let your personality, your opinions, your standpoints in. Anything that does not fit the idea of a scientist is not allowed. Queer aesthetics, queer personalities—they are not super encouraged.”

Scheldorf committed to changing attitudes, challenging exclusionary practices, and elevating marginalized viewpoints. They cofounded the DEI [Diversity, Equity, and Inclusion] council in the School for Integrative Plant Science and volunteered for the Diversity Preview Weekends (now rebranded as Consider Cornell). Currently, they serve as a coordinator at Cornell’s LGBT Resource Center, and they are active in the Society of Horticulture Graduate Students, Qgrads (formerly OSTEM), and the Graduate Diversity Council (GPSDC).

Botany beyond Gender

Scheldorf is especially proud of their work with Biodiversify, a teaching group that encourages accurate and inclusive teaching in biology and science classrooms. Biodiversify calls attention to entrenched language and behaviors that could discourage students from being excited about science. To give one example, Scheldorf notes that lectures and textbooks send a pernicious message when their examples of successful scientists are dominated by cis, white, heterosexual men. “We teach about removing some of that bias, some of that stigma from teaching materials, from the classroom, and creating more of an inclusive space,” they say.

Drawing upon their own experiences and their work with Biodiversify, Scheldorf is writing a paper about the distortions and misconceptions caused by gendered terms in science pedagogy. All sorts of human assumptions are embedded in words like male and female, mother and father, Scheldorf points out. “Nature is more complicated than the stereotypical gender binary,” they say. “Explaining [plant reproduction] in male and female terms makes it more difficult for the general public to understand how the mechanisms actually work.” Instead of male and female, they recommend using terms that describe anatomy: stamen-containing or pistil-containing, seed-bearing parent or pollen-bearing parent. “In all the conversations I had that were referencing this, people walked away feeling like they understood things better,” they say.

Scheldorf considers their advocacy work and research activities to be conceptually intertwined. “My research is focused on evaluating and looking at traits and solutions in wild species, and the DEI work is focused on bringing in historically marginalized communities and working together to make a safer and more inclusive space,” Scheldorf says. “When I would talk about DEI-related projects, I started noticing that the languages of the two were pretty similar. Phrases like, ‘if we brought this trait in, we could solve problems’ were useful in both areas. Diverse research communities that include a wider range of perspectives create more groundbreaking and foundational research.”

Diversity Seeds Innovation

To lend empirical credence to their point, Scheldorf mentions a paper by a group at Stanford. The study found that scientists belonging to underrepresented groups produce innovations at higher rates than their peers; yet when compared to equally innovative work by scientists who belong to gender and racial majorities, innovations by underrepresented scientists are less likely to garner attention—a pattern the researchers call the Diversity-Innovation Paradox.

In light of that study, Scheldorf says, removing barriers to participation in STEM is a moral imperative—not only for the sake of diversity, equity, and inclusion but also to solve urgent societal issues: “Instead of trying to recreate the wheel, or looking inside the majority population, look outside of it.”

Scheldorf hopes that their apple crossbred population will become part of the Cornell breeding program and might one day be used to make ciders. As they prepare to graduate in summer 2023, they are looking forward to a career in science policy or advocacy work. They are intent on bringing their knowledge and expertise to advocate for historically excluded groups through policies that would reduce bias and barriers.

Cornell research moves quickly. Keep up with our monthly e-newsletter.