Journal Article

The genetic basis of water‐use efficiency and yield in lettuce

Damerum, Annabelle, Smith, Hazel K., Clarkson, GJJ, Michelmore, Richard W., Truco, Maria José, Taylor, Gail

2021

Overview

Background Water supply limits agricultural productivity of many crops including lettuce. Identifying cultivars within crop species that can maintain productivity with reduced water supply is a significant challenge, but central to developing resilient crops for future water-limited climates. We investigated traits known to be related to water-use efficiency (WUE) and yield in lettuce, a globally important leafy salad crop, in a recombinant inbred line (RIL) lettuce mapping population, produced from a cross between the cultivated Lactuca sativa L. cv. Salinas and its wild progenitor L. serriola L. Results Wild and cultivated lettuce differed in their WUE and we observed transgressive segregation in yield and water-use traits in the RILs. Quantitative trait loci (QTL) analysis identified genomic regions controlling these traits under well-watered and droughted conditions. QTL were detected for carbon isotope discrimination, transpiration, stomatal conductance, leaf temperature and yield, controlling 4–23 % of the phenotypic variation. A QTL hotspot was identified on chromosome 8 that controlled carbon isotope discrimination, stomatal conductance and yield under drought. Several promising candidate genes in this region were associated with WUE, including aquaporins, late embryogenesis abundant proteins, an abscisic acid-responsive element binding protein and glutathione S-transferases involved in redox homeostasis following drought stress were also identified. Conclusions For the first time, we have characterised the genetic basis of WUE of lettuce, a commercially important and water demanding crop. We have identified promising candidate genomic regions determining WUE and yield under well-watered and water-limiting conditions, providing important pre-breeding data for future lettuce selection and breeding where water productivity will be a key target.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Abscisic acid / Agricultural production / agricultural productivity / Agricultural research / Agriculture / Aquaporins / Biomedical and Life Sciences / Carbon / Carbon isotope discrimination / Carbon isotopes / Carbon Isotopes - analysis / Chromosome 8 / chromosomes / Conductance / Crop breeding / Crop diseases / Crop resilience / Crop yields / Crops / Crops, Agricultural / Cultivars / Drought / Droughts / Efficiency / Embryogenesis / Embryonic growth stage / Gene mapping / Genetic aspects / Genomic analysis / genomics / Glutathione / glutathione transferase / Hardiness / Homeostasis / inbred lines / Inbreeding / Irrigation / isotopes / Lactuca - genetics / Lactuca - physiology / Lactuca sativa / Leafy vegetable / leaves / Lettuce / Life Sciences / Phenotype / phenotypic variation / Phenotypic variations / Physiological aspects / Plant breeding / Plant Leaves - genetics / Plant Leaves - physiology / Plant Sciences / Plant-abiotic interactions / Plants / Population / Production processes / Productivity / Proteins / Quantitative genetics / Quantitative trait loci / Quantitative Trait Loci - genetics / quantitative traits / Research Article / Resistance / salads / Stomata / Stomatal conductance / temperature / transgressive segregation / Transpiration / Tree Biology / United States / Vegetables / Water - metabolism / Water shortages / water stress / Water supply / Water use / Water‐use efficiency