Is Discrimination of 13C in Potato Leaflets and Tubers an Appropriate Trait to Describe Genotype Responses to Restrictive and Well‐Watered Conditions? uri icon

abstract

  • Selection for drought tolerance entails prioritizing plant traits that integrate critical physiological processes occurring during crop growth. Discrimination against C-13 () in leaflets ((leaflet)) and tubers ((tuber)) was compared under two water regimes in two potato-improved varieties selected to maintain yield under drought conditions (Unica and Sarnav) and one drought susceptible European cultivar (Desiree). In the control treatment, soil water content was kept at field capacity over the whole growth cycle, while in the drought treatment water supply was restricted after tuber initiation (50% of field capacity). Gas exchange and N content per unit leaf area (N-area) as well as were assessed at different stages. Sarnav showed the highest tuber yield in both water conditions, suggesting that yield in the water restriction treatment was largely driven by yield potential in this genotype. Higher stomatal conductance (g(s)) and N-area and lower (leaflet) in well-watered Sarnav suggested higher photosynthetic capacity. Under water restriction, Sarnav maintained higher g(s) indicating that carbon diffusion was a key factor for biomass accumulation under water restriction. Our results suggest the use of determined after tuber initiation as an indirect selection indicator for tuber yield under both well-watered and restricted soil water availability conditions.
  • The article objectives were: (i) to compare physiological performance and biomass accumulation among genotypes along the growing period and (ii) to test the reliability of ?leaflet and ?tuber to determine key mechanisms responsible of the varietal differences in biomass accumulation and tuber yield under different water availability levels

publication date

  • 2015
  • 2015
  • 2015