The Role of Root-Mediated Kin Recognition in a Genotypically Diverse “Neighborhood” in Triticum aestivum Defense Against Rhopalosiphum padi Herbivory
Open Access
- Author:
- Ni Chochlain, Lasair
- Millennium Scholars Program:
- Biology (BIOL)
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisor:
- John Tooker, Thesis Supervisor
Benoit A Dayrat, Honors Advisor - Keywords:
- R. padi
T. aestivum
herbivory
genotypic diversity
agriculture
entomology
wheat
aphid
plant-insect interaction
kin recognition - Abstract:
- Many studies have focused on the effects of local or “neighborhood” plant species diversity on herbivory, but few studies have considered the effects of population genotypic diversity within a major agricultural crop species, such as wheat. The herbivorous insect of interest in this study is the bird cherry-oat aphid, Rhopalosiphum padi. Based on previous research, we know that local genotypic diversity in Triticum aestivum wheat plants decreases the reproductive performance of bird cherry-oat aphids (Grettenberger and Tooker, 2016). However, the effect on herbivory of root exudates, as a form of plant-to-plant communication, is unknown. Although little is known about root communication’s influence on herbivory, researchers have shown that in the presence of roots from close relatives, plants tend to reduce root growth, hence minimizing competition with kin. In contrast, in the presence of unrelated plants from the same population, some plant species have been found to increase root growth, thereby minimizing shared access to resources. The hypothesis of this study is that if root-mediated plant kin recognition is prevented, then there will be no significant difference between aphid performance in the more genotypically diverse wheat “neighborhoods” and the minimally genotypically diverse wheat neighborhoods. I compared wheat biomass data, aphid offspring mass, and aphid tibia length in the presence and absence of aphids for different wheat varieties, neighborhood diversity, and with roots isolated or not. I did not find support for my original hypothesis, but I found that both the root treatment and the interaction of the root treatment and the neighborhood diversity resulted in significantly different mean wheat biomass. This result supports root interaction as a significant factor in plant growth, and that more research is needed to understand specifically the interaction between root communication and neighborhood diversity.