Plant strategies for maximizing growth during water stress and subsequent recovery in Solanum melongena L. (eggplant)

Authors: DELFIN, EVELYN - University Of The Philippines; DROBNITCH, SARAH - Colorado State University; Comas, Louise

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/5/2021
Publication Date: 9/1/2021
Citation: Delfin, E.F., Drobnitch, S.T., Comas, L.H. 2021. Plant strategies for maximizing growth during water stress and subsequent recovery in Solanum melongena L. (eggplant). PLoS ONE. 16(9). Article e0256342. https://doi.org/10.1371/journal.pone.0256342.
DOI: https://doi.org/10.1371/journal.pone.0256342

Interpretive Summary: In the Philippines and much of southeast Asia, climate change is projected to increase the incidence of severe drought in a historically wet tropical region. Eggplant, Solanum melongena L., is ranked as one of the most important vegetables consumed and produced in the Philippines but drought adversely effects plant size and fruit yield. In this study, we selected four genotypes of S. melongena with previous evidence of drought tolerance and identified the growth strategy associated with productivity under drought. We observed that two genotypes, PHL 4841 and PHL 2778 quickly grew into large plants with smaller, thicker leaves and increasingly poor hydraulic status, whereas PHL 2789 and Mara maintained safer water status and larger leaves but sacrificed large gains in biomass. The top deficit performer, 2778, showed a significant increase in root allocation relative to other genotypes, suggesting a drought avoiding strategy. Biomass traits of all genotypes were negatively impacted by deficit watering and remained impacted after a week of hydraulic recovery; however, physiological traits and allocation to root growth recovered after one week of normal watering, indicating a strong capacity for eggplant to rebound from short-term deficits.

Technical Abstract: In the Philippines and much of southeast Asia, climate change is projected to increase the incidence of severe drought in a historically wet tropical region. Eggplant, Solanum melongena L., is ranked as one of the most important vegetables consumed and produced in the Philippines but drought adversely effects plant size and fruit yield. In this study, we selected four genotypes of S. melongena with previous evidence of drought tolerance and identified the growth strategy associated with productivity under drought. We observed that two genotypes, PHL 4841 and PHL 2778 quickly grew into large plants with smaller, thicker leaves but increasingly poor hydraulic status, whereas PHL 2789 and Mara maintained safer water status and larger leaves but sacrificed large gains in biomass. The top deficit performer, 2778, showed a significant increase in root allocation relative to other genotypes, suggesting a drought avoiding strategy. Biomass traits of all genotypes were negatively impacted by deficit watering and remained impacted after a week of hydraulic recovery; however, physiological traits such as electron transport capacity of photosystem II, and proportional allocation to root biomass, fine root length, and leaf area recovered after one week of normal watering, indicating a strong capacity for eggplant to rebound from short-term deficits.