Abstract Detail

The Science of Meaningful Undergraduate Research Experiences

Chomentowska, Anri [1], Miller, Jill [2].

Undergraduate research on mating systems and interspecific reproduction in wild tomatoes: reflecting on the scientific and personal significance.

Reproductive strategies are crucial life history traits with consequences on genetic diversity and evolutionary history of plants. One such strategy is the plants’ mating system––recent research suggests that molecular mechanisms underlying mating systems, specifically gametophytic self-incompatibility (GSI), may be implicated in the establishment of reproductive barriers between species. Particularly, unidirectional barriers are often observed during reproduction between self-compatible and self-incompatible species.
As part of my undergraduate thesis project, we investigated the presence and direction of interspecific reproductive barriers among closely related species of Solanum section Lycopersicon (wild tomato clade). To examine potential contributions of self-incompatibility to unilateral incompatibility, we conducted controlled pollinations among species with different mating systems. These included reciprocal crosses between self-incompatible S. arcanum and a self-compatible population of S. peruvianum, which lacks the expression of the female determinant gene of GSI (S-RNase), and crosses between S. arcanum and self-compatible S. pimpinellifolium, which is polymorphic in pollen-side GSI gene Cullin1. We measured fruit set, seed set, and F1 viability for all crosses.
We found unilateral incompatibility between self-incompatible Solanum arcanum and self-compatible S. peruvianum, where 46% fruit set resulted from a S. peruvianum x S. arcanum (dam x sire) cross but resulted in no fruit set in the reciprocal cross. Interestingly, crosses between S. arcanum and a self-compatible S. pimpinellifolium were compatible in both directions, regardless of Cullin1 allele. These conflicting results challenge previous assumptions about how mating systems relate to interspecific incompatibilities. Moreover, there were fitness costs to F1 hybrids produced from the compatible crosses, but the costs differed among cross types, indicating a complexity even in post-zygotic interactions.
Importantly, this project was only possible with the efforts of three undergraduate research assistants in the lab, who assisted in pollinations, data collecting, and molecular work. As a college senior, I was guided by my PI at every step––still, the ownership given to me and the chance to teach others in an undergraduate-only lab left a sense of achievement beyond the scientific results of the thesis. For this colloquium, I will highlight how being both a mentee and a mentor helped shape not only this work but my current research interests and ongoing projects as a graduate student, as well as share my first-account impact of an undergraduate research experience as a first-generation, low-income, international college student.

1 - Yale University, Department of Ecology and Evolutionary Biology, 165 Prospect St, New Haven, CT, 06511, USA
2 - Amherst College, Department Of Biology, Science Center, Amherst, MA, 01002, United States

mating system
reproductive biology
Undergraduate research.

Presentation Type: Colloquium Presentations
Session: COL10, The Science of Meaningful Undergraduate Research Experiences
Location: Virtual/Virtual
Date: Friday, July 31st, 2020
Time: 1:15 PM
Number: COL10004
Abstract ID:449
Candidate for Awards:None

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