Population genomics of adaptation of wild pearl millet (Cenchrus americanus) – MILDIV

The project will investigate the genome wide diversity of 48 populations of wild pearl millet distributed across the West African distribution area and along a climatic gradient. Next generation sequencing technologies will be used to generate hundreds of thousands of markers to perform genome-wide- selection scan. Bayesian and spatial approaches will be used to detect signatures of selection.

The expected results of this project are: i) a comprehensive description of the evolutionary history of wild pearl millet; ii) a large scale spatial genetic structure snapshot of wild pearl millet populations; iii) an identification of genes and functional alleles of interest for future climatic conditions and iv) an increased knowledge on evolutionary processes.

Results from this study will directly benefit agronomy by providing new insight of potential genes of interest for the development of mil varieties adapted to more arid conditions.

Results from this study will be published in peer-review journals.

Globally, around a billion people do not have adequate food to meet their basic nutritional needs. World population is expected to rise to 9 billion by 2050. The challenge for agriculture is to meet a rising demand for food in a warmer planet. African agriculture will be particularly affected by current global warning. Pearl millet, Cenchrus americanus, is 7th in crop worldwide rankings and plays a significant role in food security in the driest environment of Africa. In a 2 to 4°C warmer word, actual diversity in cultivated crop might not be enough for such adaptation. Wild pearl millet grows in more extreme climatic conditions than cultivated types since wild populations are found at the edge of the Sahara dune desert. Therefore, the wild pearl millet represents a reservoir of functional allele that will be possible to use for future evolution and adaptations to changing conditions.

The MILDIV project proposes to identify genes or functional alleles that could be used to improve resilience or adaptations of crops to face future climatic changes. In order to do this, the project will investigate the genome wide diversity of 48 populations of wild pearl millet distributed across the West African distribution area and along a climatic gradient. Next generation sequencing technologies will be used to generate hundreds of thousands of markers to perform genome-wide- selection scan.

First, the use of Bayesian approaches will allow to estimate the past and current demographic parameters of the populations and to establish a “neutral” model. Following this, FST- based methods and correlation methods along climatic gradient will be used to detect signatures of selection. False positive discovery rate will be assessed using the “neutral” model on these different “selection” tests. Finally, the developed spatial model will be used to identify outlier locus.

The expected results of this project are: i) a comprehensive description of the evolutionary history of wild pearl millet; ii) a large scale spatial genetic structure snapshot of wild pearl millet populations; iii) an identification of genes and functional alleles of interest for future climatic conditions and iv) an increased knowledge on evolutionary processes. Results from this study will directly benefit agronomy by providing new insight of potential genes of interest for the development of mil varieties adapted to more arid conditions.