Feeding the world: Opportunities and challenges of phenotyping plant salt tolerance

Research |

The world's population is growing - and so is the hunger for grain. More grain must be produced to feed the world's people, but climate change brings frequent weather extremes that make grain production difficult. One way to increase yields in the future is to grow crops on saline soils.

Plant characteristics are recognized using sensor techniques
The PhD student was using a spectral sensor for phenotyping of salt tolerance traits of wheat varieties in a greenhouse study (Photo: Chair of Plant Nutrition / TUM).

PD Dr. Yuncai Hu and Emeritus Prof. Dr. Urs Schmidhalter from the TUM School of Life Sciences at the Technical University of Munich (TUM) have therefore been researching the development of salt-tolerant plants for many years.

"Currently, more than 6% of the world's land area and 20% of irrigated land is salinized, and salinization is steadily increasing," says PD Dr. Hu. "If we identify the plant morphological and physiological traits for salt tolerance, we can breed more salt-tolerant plants and make an important contribution to food security”, Hu explains. “By 2050, the world's population is expected to grow by 34%, and global food production would need to increase by 43% to meet demand for cereals”, he said.

Phenotyping platforms enable time series measurements

High-throughput phenotyping, which has emerged in recent years to identify plant traits, is currently based on advanced remote sensing technologies that enable rapid, low-cost measurement of many phenotypes across time and space with little labor. A major advance in high-throughput phenotyping platforms is the ability to assess plant traits non-destructively, with increased experimental capacity for genotypes, treatments, and biological replicates. This advance enables time-series measurements necessary to track growth and stress trends in individual plants. "The results from our studies have shown that investments in high-throughput phenotyping technologies have clear benefits for interpreting genotype-environment interactions, even in developing countries," Hu said.

Plant characteristics are recognized using sensor techniques

A review article titled: "Opportunity and challenges of phenotyping plant salt tolerance" by PD Dr. Hu and Prof. Schmidhalter is now published in Trends in Plant Science (Special Issue: Food Security, May 2023).

The article analyzes the potential opportunities and major challenges in improving plant salt tolerance using advanced field phenotyping technologies. The article suggests that the most useful and important sensing techniques for assessing key morphological and physiological traits of plant salt tolerance are RGB imaging, spectral, and thermal sensors. The article also provides guidance on how high-throughput field phenotyping can be readily applied to future breeding of salt-tolerant plants and how to improve the development of genomic approaches.

Publication: Hu Y, Schmidhalter U (2023) Opportunity and challenges of phenotyping plant salt tolerance. Trends in Plant Science 28(5): 552-566. DOI: doi.org/10.1016/j.tplants.2022.12.010

Background information: TUM Press (2008) "Salt tolerant wheat grows even in the desert," published 04/30/2008.

Susanne Neumann
TUM School of Life Sciences
Press and Public Relations