Project

Has photosynthesis increased with breeding for higher-yielding soybean cultivars?

Soybean is an important crop and increasing photosynthesis can potentially increase soybean yield. To exploit this potential, this project aims to identify natural variation in soybean photosynthesis. The question is if breeding for modern, high-yielding cultivars has inadvertently selected for higher photosynthesis. Therefore, this variation is investigated in a panel with a range of old and new cultivars.

Project description

Soybean is a major source of vegetable protein worldwide. Improved agronomic practices and breeding efforts have led to yield increases e.g., with 23.3 kg ha^-1 y^-1 between 1924 and 2012 in the USA. However, further genetic improvements are required to meet future increases in demands for food and for plant-based protein in particular.

Therefore, new strategies are required to achieve further increases in yield. One strategy is increasing photosynthesis, which has been shown to have the potential to increase biomass and yield. This has recently also been shown in soybean. To exploit such potential, there is a need to identify naturally existing variation for photosynthesis, for soybean in particular. And, it is the question whether breeding for higher yielding cultivars over the past decades has inadvertently already selected for higher photosynthesis. The first step is therefore to explore the natural variation in photosynthesis in a panel with a range of different soybean cultivars, ranging from old to new elite lines.

Objectives and methods

The aim of the project is to understand the effect of breeding on the photosynthetic performance of a diverse set of soybean cultivars, form old varieties to new elite lines.

This will improve our understanding of how breeding may have (inadvertently) affected photosynthesis and whether this genetic variation can be utilized.

Required skills

Knowledge of plant physiology, in particular photosynthesis
Knowledge of experimental design and statistical analysis
Experience or affinity with measurements of photosynthesis
Experience or affinity with programming (in R)

Types of research/work

The project will involve a combination of the following types of work:

Design and execution of growth experiments with a range of soybean cultivars (in a controlled environment)
Measurement and analysis of plant growth and biomass
Measurement of photosynthesis (advanced gas exchange, pulse-modulated chlorophyll fluorescence)
Modelling of photosynthesis (using R)