Genetic and genomic resources for improving proso millet (Panicum miliaceum L.): a potential crop for food and nutritional security

Realizing visionary goals for the International Year of Millet (IYoM): accelerating interventions through advances in molecular breeding and multiomics resources

MAIN CONCLUSION

Leveraging advanced breeding and multi-omics resources is vital to position millet as an essential "nutricereal resource," aligning with IYoM goals, alleviating strain on global cereal production, boosting resilience to climate change, and advancing sustainable crop improvement and biodiversity. The global challenges of food security, nutrition, climate change, and agrarian sustainability demand the adoption of climate-resilient, nutrient-rich crops to support a growing population amidst shifting environmental conditions. Millets, also referred to as "Shree Anna," emerge as a promising solution to address these issues by bolstering food production, improving nutrient security, and fostering biodiversity conservation. Their resilience to harsh environments, nutritional density, cultural significance, and potential to enhance dietary quality index made them valuable assets in global agriculture. Recognizing their pivotal role, the United Nations designated 2023 as the "International Year of Millets (IYoM 2023)," emphasizing their contribution to climate-resilient agriculture and nutritional enhancement. Scientific progress has invigorated efforts to enhance millet production through genetic and genomic interventions, yielding a wealth of advanced molecular breeding technologies and multi-omics resources. These advancements offer opportunities to tackle prevailing challenges in millet, such as anti-nutritional factors, sensory acceptability issues, toxin contamination, and ancillary crop improvements. This review provides a comprehensive overview of molecular breeding and multi-omics resources for nine major millet species, focusing on their potential impact within the framework of IYoM. These resources include whole and pan-genome, elucidating adaptive responses to abiotic stressors, organelle-based studies revealing evolutionary resilience, markers linked to desirable traits for efficient breeding, QTL analysis facilitating trait selection, functional gene discovery for biotechnological interventions, regulatory ncRNAs for trait modulation, web-based platforms for stakeholder communication, tissue culture techniques for genetic modification, and integrated omics approaches enabled by precise application of CRISPR/Cas9 technology. Aligning these resources with the seven thematic areas outlined by IYoM catalyzes transformative changes in millet production and utilization, thereby contributing to global food security, sustainable agriculture, and enhanced nutritional consequences.

Gamma irradiation to induce beneficial mutants in proso millet (Panicum miliaceum L.): an underutilized food crop

PURPOSE

Proso millet is a potential crop for food, nutritional security, and sustainable agriculture, particularly in the context of climate change. It is one of the traditional millet crops in cultivation in Tamil Nadu and India. Self-pollinated nature of this crop makes evolutionary process a terminal one and creating variability to broaden the genetic base is important. The objective of the study was to optimize mutagenic dose of gamma mutagen, document types of mutations and identify mutants for high grain yield (GY) and fodder yield (FY), hence to determine the feasibility of gamma mutagenesis in proso millet crop improvement.

MATERIALS AND METHODS

A mutation breeding program with 10 doses of gamma irradiation, i.e. 100, 200, 300, 400, 500, 600, 700, 800, 900 and 1000 Gy were imposed on seeds of variety ATL 1, a popular variety in India. Roll paper method, tray method and field evaluation were carried out to determine the LD₅₀ and GR₅₀ doses. Based on viable mutation frequency in M₂ generation, mutagenic effectiveness and efficiency was estimated. Targeted selection for yield and yield contributing traits was carried out in M₂, M₃ and M₄ generation to identify high yielding mutants.

RESULTS

The LD₅₀ and GR₅₀ doses of gamma were estimated to be 418 Gy and 542 Gy, respectively. Based on results from probit analysis, mutagenic effectiveness, mutagenic efficiency and mutation spectrum, the optimum treatment dose of gamma was concluded to be 400 Gy. High frequency, i.e. 10.96% of phenotypic mutants was identified in the M₂ generation. The broad range of mutants identified in M₂ generation had mutations for plant height, plant habit, panicle shape, compactness, and length, days to 50% flowering (DFF), lodging resistance, tillering, leaf phenotype, apiculus color, culm branching, stem and leaf hairiness, sheath pigmentation, seed color and shape and seed coat attachment. Eight high yielding mutant families were isolated in M₄ generation. The mean single plant GY and FY of these mutants ranged between 25 to 51 g and 40 to 68 g respectively while in control it was 15 g and 30 g, respectively.

CONCLUSIONS

The wide spectrum and high frequency of mutations both for qualitative and quantitative traits suggest mutation induction as a promising method for creating novel variations in proso millet. The high yielding mutants identified can be utilized for varietal development both for grain and fodder purpose after further stability and quality evaluations in the advanced generations.