Please Note: The main page lists projects via BBSRC Research Theme(s) quoted and then relevant Topic(s).
Optimising nitrogen-fixing potential of British-grown lentil
Secondary Supervisor(s): Dr Joshua Quick
University of Registration: University of Birmingham
BBSRC Research Themes: Sustainable Agriculture and Food (Plant and Crop Science)
Project Outline
Global food systems are overdependent on four crops (rice, wheat, maize, potato) that supply close to half of global calorie intake compared to ~7,000 plant species that humans used for diet in the pre-agriculture era. The intensive and fertiliser-dependent cultivation of these few major crops is a major driver of biodiversity loss and climate change.
One viable strategy for sustainably achieving food and nutrition security with reduced environmental impact is to diversify food systems by encouraging the use of underutilised crops, particularly pulses. Pulses, like lentil, are climate-smart legume crops that produce protein-rich seeds without requiring fertiliser application. They obtain their “natural fertiliser” through symbiotic relationship with nitrogen-fixing microbes (rhizobia) that are accommodated in their root nodules, and also leave valuable residual nitrogen for subsequent crops.
This project aims to maximise the nitrogen-fixing potential of British-grown lentil by optimising symbiotic relationship with native rhizobia species in UK soils. Rhizobium leguminosarum bv. Viciae (Rlv) is a group of rhizobia species with the ability to form nodules (AFN) with legumes in the Fabeae tribe including pea, faba bean, and lentil. However, different Rlv strains show preference for different crops. As a new crop in the UK, identifying Rlv strains from UK soils that can preferentially nodulate lentil can help boost lentil cultivation in the UK. In addition to variation in AFN, Rlv strains are known to also vary in their nitrogen fixing efficiency (NFE) once accommodated in the root nodules. Furthermore, lentil genotypes show variation in the number of root nodules that they form to accommodate Rlv.
Aim and Objectives
The long-term goal of this project is to identify the ideal combination of high-nodulating lentil genotypes and native rhizobia strains from UK soils with high NFE that can support the productive cultivation of lentil and to enrich UK soils. The project will be carried out under three objectives:
(A) Screening global lentil diversity for high-nodulating genotypes. We already have access to a core collection of 197 lentil genotypes from an international genebank. This core collection captures the genetic diversity of a wider collection of 14,000 global lentil genotypes. We will screen this rich reservoir of lentils genetic diversity to identify genotypes with high nodulation potential in UK soils.
(B) Isolate and sequence lentil-nodulating rhizobia strains from UK soils. We will screen soil samples to isolate and biobank rhizobia strains from UK soils that can nodulate lentil. We will also sequence the genomes of the isolated rhizobia strains using Nanopore sequencing. This will allow to us to fully characterise the genetic diversity of rhizobia strains in UK soil.
(C) Identify lentil-rhizobia pairing with optimal nitrogen fixing efficiency. Having studied genetic diversity on the plant and microbe populations, we will conduct a high-throughput screen to find an optimal combination of lentil genotype and rhizobia strain that maximises nodulation without compromising plant growth and yield.
The project will combine skills in plant physiology, microbiology, next generation sequencing and bioinformatics. You will get to work on an exciting project that can contribute to food security and environmental sustainability.
References
1. Mendoza-Suárez, Marcela A., et al. "Optimizing Rhizobium-legume symbioses by simultaneous measurement of rhizobial competitiveness and N2 fixation in nodules." Proceedings of the National Academy of Sciences 117.18 (2020): 9822-9831.
2. Rajendran K, Coyne CJ, Zheng P, et al. Genetic diversity and GWAS of agronomic traits using an ICARDA lentil (Lens culinaris Medik.) Reference Plus collection. Plant Genetic Resources: Characterization and Utilization. 2021;19(4):279-288. doi:10.1017/S147926212100006X.