Assessing Transgenerational Stress Memory Induced by Water-Saving Irrigation Management in Peanut (Arachis hypogaea L.)

• Main Author: Racette, Kelly Ann
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01-01-2019
• Subjects: Agronomy; Plant sciences; Water Resources Management
• ISBN: 9798691293696

Recent studies in plants and other organisms have suggested that memories of stress events can be inherited from parent to offspring through a process known as transgenerational stress memory (TSM). However, the study of TSM in crop plants is in its infancy, despite its potential role in adaptation. Addressing this gap in knowledge would likely improve our ability to both breed and manage crops to promote stress tolerance. Improving crop response to drought stress is of particular concern, due to the diminishing availability of water in agricultural regions across the globe. Thus, the overarching objective of the research presented in this dissertation was to assess TSM of water deficit in peanut, with a focus on the early development of seedlings. To address this objective, seeds were collected from parents that received two water regimes representing two parent stress histories (PSH) with contrasting potential to induce TSM: 1) offspring of non-stressed parents and 2) offspring of stressed parents. The field performance of plants with these two PSH of five peanut genotypes was inconsistent, highlighting the complex relationship between genotype, TSM, and the interaction of these two factors with the environment. Results of this study also support the hypothesis that effects of TSM are greatest during early developmental stages of crops. This hypothesis was therefore examined in greater depth through the analysis of seed and seedling vigor traits, including root architecture and root behaviors of seedlings. These studies illustrated the high variability between genotypes in how and when TSM is expressed. The major findings of these studies contribute important documentation of the existence of TSM in a crop species and the need to further examine TSM capacity in breeding and management for stress adaptation. Further, this knowledge suggests irrigation management in the parent generation of certain genotypes could be customized for the existence of TSM to maximize the quality and vigor of the subsequent generation.