Mining maize gene bank diversity for desirable alleles

Abstract

Modern agriculture combats a dual challenge-meeting societal demands for eco-friendly practices and diverse, healthier products and sustaining production in the face of climate change. This combination of factors raises unprecedented questions about how to identify and improve suitable plant materials that can be delivered to farmers and other end users. In this context, understanding the role of seed gene banks is crucial. They serve multiple functions - collecting new plant materials, conserving them under controlled environments, testing seed health, conducting research to characterise and evaluate these materials for breeding important traits and resilience against abiotic and biotic stresses, and distributing them to plant breeders, researchers, farmers, and the food industry. The vast array of traits found in cereal genetic resources maintained in ex situ collections - gene banks, along with their adaptability - is vital for enhancing the resilience of agricultural production systems and advancing innovative, efficient agro-food systems and other bio-based value chains. Thus, they represent a key form of natural capital necessary for stability and adaptability in agriculture and for fostering a sustainable bio-economy. Despite the importance of genetic diversity in plant breeding, most cereal ex situ collections are underutilised, with less than 5% actively used. Despite efforts over the past few decades to expand cereal ex situ collections globally, their size complicates the maintenance and evaluation of the genetic diversity they encompass. Many accessions lack sufficient evaluation data, hindering effective responses to user needs. Typically, only minimal passport data is available, and detailed information on unique traits is often missing. Significant gaps in documentation and characterisation hinder breeding programs. Only 64% of accessions are morphologically characterised, 51% agronomically, 14% biochemically, and about 22% for biotic traits. Hence, comprehensive characterisation is essential for maximising the value of cereal genetic resources and helping users select appropriate germplasm