Millets are small-seeded cereal grains consumed as food by millions of people throughout the world. They are often referred to as 'poor man's cereal, has a long history of cultivation of more than 5000 years. They comprise of pearl millet, sorghum and small millets, namely finger millet (Ragi), foxtail millet (Navane), kodo millet (Haraka), proso millet (Baragu), barnyard millet (Udalu), little millet (Saame) and browntop millet (Korale). ICRISAT introduced the term smart food i.e., the food that should fill the following criteria of being ‘Good for you’, ‘Good for plant’, and ‘Good for the farmer’’. Millets are also regarded to have antimicrobial and DNA damage protection activities due to their phytochemical content. Recently Prof. M. S. Swaminathan designated millets as 'nutritious millets' and realizing the nutrient richness of the grains they are now gazetted as “Nutricereals”. Considering their importance, it is essential to harness genetic variability for crop improvement programs.

Among artificial hybridization techniques, the contact method of hybridization is widely followed. However, the success rate of obtaining true F1s is 2 % to 3 %. In finger millet, hot water treatment (52°C) for 3 to 5 min causes temporal male sterility. Partial-sterile (PS) lines developed at the Project Coordinating Unit, Small Millets, UAS, Bangalore are in use, percent seed set ranged from 27.4 to 49.4, with an average of 40.10 %. In proso millet, little millet and browntop millet, apart from contact method, hot water treatment, hand emasculation and the USSR (Union of Soviet Socialist Republics) method of hybridization are also followed. Small Millets University of Agricultural Sciences Bengaluru (SMUASB) method in proso and little millets has a success rate of 56 % to 60 % in obtaining true hybrids2.

Using general and mixed linear models, 44 common SNP-trait associations contributing 4.80-17.79% phenotypic variance for calcium trait were identified. Two putative SNP marker sequences were found homologous to candidate genes viz., calmodulin-binding protein (CBP) and CBL-Interacting Protein Kinase7 (CIPK7) of foxtail millet, which plays a pivotal role in grain calcium accumulation3.

To understand complete biological process of an organism, multi-omics is essential and plays role in rapid breeding of crops. Omics information on millets should advance more rapidly as cereal crops. An integrated approach like GWAS combined with metabolite profiling is used. MutMap+ has been used to map the dwarfing gene D3 on chromosome 8 of foxtail millet1. Revitalization of millet crops by conventional, advanced genetic and genomics shall be a miracle to remove malnutrition and improve human health of poor nourished people, thus helps in achieving nutritional and food security.

References: 

1. LYDIA PRAMITHA, J., GANESAN, J., FRANCIS, N., RAJASEKHARAN, R. AND THINAKARAN, J., 2023, Revitalization of small millets for nutritional and food security by advanced genetics and genomics approaches. Front. genet., 13:1007552.

2. NAGARAJA, T. E., NANDINI, C., BHAT, S. AND PARVEEN, S., 2023, Artificial hybridization techniques in small millets-A review. Front. Plant Sci., 14: 1112117. 

3. SHARMA, D., TIWARI, A., SOOD, S., MEHER, P. K. AND KUMAR, A., 2022, Identification and validation of candidate genes for high calcium content in finger millet [Eleusine coracana L.] through genome-wide association study. J. Cereal Sci., 107: 1035-1042.