Increasing Water-Use-Efficiency in Potato by Precision-Breeding and GM-Approaches

Both in Danish and international perspective, the prime challenge posed by climate change to agriculture will be the adaptation of crops to cope with less water. The Danish Meteorological Institute foresees up to 25% reduction in precipitation and longer dry spells during summer, and a new study predicts c. 90% increase in irrigation needs in 2070-2100 in the Skern Å catchment. The current project acknowledge that potato is the most drought sensitive crop in Danish agriculture as well as being between the four most important staple foods in the world.



Recent field experimental results on potatoes exposed to the irrigation technique of partial root-zone drying (PRD) have demonstrated that transpiration may be reduced by 15-20% without yield loss. The PRD technique induces the plants’ endogenous abscisic acid (ABA) signaling system to restrict stomatal opening. It is thus believed that root-derived ABA plays a central role for the observed improvement of water-use-efficiency (WUE), i.e. the ratio between biomass production and transpirational water use (Unit: g dm/kg water), which is the key trait investigated in the present project. Our aim here is to initiate breeding of potatoes with high WUE by using a novel, scientific framework that combines ecophysiological modeling with quantitative trait loci analysis. For each of 184 offspring potato clones of our mapping population, model-parameters will be established by phenotypic observations i.e. measurement of photosynthesis etc. in climate chambers, glasshouse and the field. Established AFLP markers will be supplemented with SNP-markers, to obtain sufficient markers on each chromosome to enable cloning of candidate genes. Also the aim is to develop an easier way of QTL mapping, which relies on RNA sequencing. When the result of the QTL mapping is available it is possible to perform precision-breeding for high WUE, where plants can be used by organic farmers. Alternatively the candidate genes can be cloned to produce a GM potato with high WUE. Parners: AaU, KU, and LKF Vandel.