Evaluation of cassava genotypes (Manihot esculenta Crantz) for drought tolerance and susceptibility under water deficit conditions
Year: 2024
Type: article
Abstract: InformationDrought stress detriments crop yields and exacerbates food insecurity.Cassava, an inherently drought tolerant crop, is a sustainable solution.This study evaluated cassava genotypes' varied responses to drought enabling selection of superior candidates with improved performance.Field-assessed drought tolerant (DT) and drought susceptible (DS) genotypes varied in leaf wilting, abscission, staygreen, root development and bulking.Under greenhouse experiments, well-watered (WW) plants showed significantly (P ≤ 0.001) higher vegetative growth and physiological response than plants exposed to water deficit (WD).Relative to WW treatment, WD reduced total leaves formed by ~20%, leaf retention by ~67%, plant height by ~26%, shoot fresh weight by ~62%, shoot dry weight by ~41% and shoot water content by ~49%.These generally implied negative effects of water deficit on cassava growth and development.Amongst genotypes, DT candidates (98/0002, 95/0306, M98/0068, I92/0067 & 94/0039) exhibited the least decline for most of these traits compared to DS counterparts (92/0427, TME-419 & I96/1439) under WD treatments.Physiologically, significantly (P ≤ 0.001) higher leaf stomatal conductance (Gs) was measured from WW plants than WD-plants.Genotypically, a decrease in higher, moderate and lower Gs was recorded between the DT and DS genotypes.Cessation of leaf Gs after 10 days of WD and increased Gs rates after a day of re-watering respectively, mimicked drought-induced stomatal closure and stomatal re-opening.These results imply the potential use of either parameter(s) for rapid screening for drought stress tolerance in cassava genotypes and thus benefit breeding programs for drought-tolerant cassava.Selected morpho-physiologically superior genotypes such as 98/0002, 95/0306, M98/0068, I92/0067 and 94/0039 could be cultivated for better cassava productivity under drought stress.
Author: Charles Orek
Language: English
Topic: Cassava research and cyanide
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: hybrid
OpenAlex ID: W4405757968