Unraveling the genetic basis of drought tolerance in potato

Abstract Background: Potato is highly valued as a food security crop but is sensitive to drought stress. A relatively small reduction of the optimum amount of water can already result in a significant reduction in tuber yield. Therefore, unravelling the genetic basis of drought tolerance is important in order to enhance tolerance to drought in potato. We have evaluated a diploid potato backcross mapping population for drought tolerance under field conditions. Water application was withheld at the stage of tuber initiation. At the end of the drought stress period, we collected data on a number of morphological and physiological traits.Results: The potato population showed significant reduction in several growth traits measured, as well as in tuber yield. We applied quantitative trait locus (QTL) analysis to find genomic regions underlying these drought tolerance traits. We found 60 QTL for several of the traits measured under well-watered and drought stress conditions. From the total number of QTLs identified, 21 were detected under water stress conditions while 39 QTLs were identified under well-watered conditions. Drought specific QTLs for tuber fresh yield was detected on chromosome 7, 9 and 12.Conclusions: There is genetic variation in potato for drought tolerance and QTLs discovered for drought tolerance traits in this study can aid in improving potato for drought tolerance.