Which potatoes thrive despite insufficient phosphorus?

Göttingen University research team analyses different cultivars of tuber Phosphorus is an essential plant nutrient that is becoming increasingly scarce around the world. This means the fertiliser has to be used as efficiently as possible and any loss of nutrients due to leaching and erosion must be minimised. This is challenging for potato farmers, as potatoes need a lot of phosphorus due to their weak root systems. A research team from the University of Göttingen has investigated how a limited phosphorus supply affects the efficiency of plants to use phosphorus and the quality of resulting tubers. The results were published in the journal Frontiers in Plant Science.

"Although the consequences of low phosphorus levels on growth in potatoes are well known, so far there has been little research about how efficiently the individual varieties use this fertiliser and whether the tuber quality is affected," explains first author Leangsrun Chea from the Division of Quality of Plant Products at Göttingen University. The researchers grew and analysed six varieties of potato at three different levels of phosphorus in the soil. These varieties are grown primarily for processing and culinary purposes, known as starch and table potatoes respectively. Most of the table potato varieties showed a high use efficiency at low phosphorus levels. They were therefore classified as phosphorus-efficient varieties. Lower phosphorus supply reduced the starch content, but the concentration of minerals as well as the amount of antioxidants in the tubers increased. Potatoes with increased concentrations of minerals and phytochemicals can make a valuable contribution to healthy nutrition. In contrast, the starch varieties and an older table variety did not produce tubers under these conditions.

"The phosphorus-efficient varieties identified by this research are potential candidates for cultivation in soils where phosphorus is limited and at the same time produce tubers with improved nutrient quality," reports Dr Marcel Naumann, initiator of the study. Professor Elke Pawelzik, head of the department, adds that although low phosphorus supply improved quality in phosphorus-efficient varieties, the yield was significantly reduced. "Future research should therefore focus on finding out how to ensure that yield is not reduced significantly, despite the phosphorus deficiency." Apart from breeding varieties to improve their tolerance to phosphorus deficiency, this could also be achieved by using beneficial microorganisms.

Original publication: Chea, L. et al. (2021) Cultivar-dependent responses in plant growth, leaf physiology, phosphorus use efficiency, and tuber quality of potatoes under limited phosphorus availability conditions. Front. Plant Sci. 12:713862. doi:   https://doi.org/10.3389/fpls.2021.723862

Text also available at: https://www.frontiersin.org/articles/10.3389/fpls.2021.723862/full
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