Genomic Approaches to Enhance Stress Tolerance for Productivity Improvements in Pearl Millet

Abstract

Pearl millet [Pennisetum glaucum (L.) R. Br.], the sixth most important cereal crop (after rice, wheat, maize, barley, and sorghum), is grown as a grain and stover crop by the small holder farmers in the harshest cropping environments of the arid and semiarid tropical regions of sub-Saharan Africa and South Asia. Millet is grown on ~31 million hectares globally with India in South Asia; Nigeria, Niger, Burkina Faso, and Mali in western and central Africa; and Sudan, Uganda, and Tanzania in Eastern Africa as the major producers. Pearl millet provides food and nutritional security to more than 500 million of the world's poorest and most nutritionally insecure people. Global pearl millet production has increased over the past 15 years, primarily due to availability of improved genetics and adoption of hybrids in India and expanding area under pearl millet production in West Africa. Pearl millet production is challenged by various biotic and abiotic stresses resulting in a significant reduction in yields. The genomics research in pearl millet lagged behind because of multiple reasons in the past. However, in the recent past, several efforts were initiated in genomic research resulting into a generation of large amounts of genomic resources and information including recently published sequence of the reference genome and re-sequencing of almost 1000 lines representing the global diversity. This chapter reviews the advances made in generating the genetic and genomics resources in pearl millet and their interventions in improving the stress tolerance to improve the productivity of this very important climate-smart nutri-cereal.

Pearl Millet: A Climate-Resilient Nutricereal for Mitigating Hidden Hunger and Provide Nutritional Security

“…Various molecular markers and genomic tools have been developed and applied for QTLs/genes identification, genetic diversity, and MAB to enhance pearl millet breeding by exploring its genetic potential at the molecular level (Serba and Yadav, 2016 ; Anuradha et al, 2017 ; Bollam et al, 2018 ; Kumar et al, 2018 ; Singhal et al, 2018 ; Ambawat et al, 2020 ; Srivastava et al, 2020a , b ). Various molecular markers developed for pearl millet include restriction fragment length polymorphism [RFLP (Liu et al, 1994 )], random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism [AFLP (Devos et al, 1995 )], sequence-tagged sites [STSs (Allouis et al, 2001 )], simple sequence repeat [SSRs (Qi et al, 2004 ; Meena et al, 2020 ; Srivastava et al, 2020a )], single-stranded conformation polymorphism-SNP [SSCP-SNP (Bertin et al, 2005 )], expressed sequence tag-derived simple sequence repeats [EST-SSRs (Senthilvel et al, 2008 ; Rajaram et al, 2013 )], DArT array technology [DArTs (Senthilvel et al, 2010 ; Supriya et al, 2011 )], conserved intron-specific primers [CISP (Sehgal et al, 2012 )], and single nucleotide polymorphisms [SNPs (Sehgal et al, 2012 )].…”

“…(Serba and Yadav, 2016 ). Genetic improvement of pearl millet through increased production was realized using hybrid technology and conventional breeding methods of selection (Yadav and Rai, 2013 ; Yadav et al, 2021 ) but later, various biotechnological and genomic approaches were used for further improvement (Varshney et al, 2017 ; Bollam et al, 2018 ; Ambawat et al, 2020 ). Genetic maps, next-generation sequencing (NGS), genotyping-by-sequencing (GBS), genome-wide association studies (GWAS), synteny studies, expression profiling, fine QTL mapping, candidate gene identification and genetic engineering, gene pyramiding, bioinformatics and systems biology are some of the useful platforms, which are further being used for the genetic improvement of this nutricereal.…”

Establishing Breeding Priorities for Developing Biofortified High-Yielding Pearl Millet (Pennisetum glaucum (L.) R. Br.) Varieties and Hybrids in Dosso Region of Niger

“…The second most important constraint was drought. Pearl millet production is mostly practiced on marginal lands with scanty rainfall and drought stress, which represents a major constraint on the grain yield in these farming systems [26]. Efforts have been made to increase the pearl millet yield through mineral fertilization and the selection of early-maturing varieties that escape late-season drought [27].…”

Exploitation of Heterosis in Pearl Millet: A Review

“…It is gaining importance as climate-smart nutri cereal, and is one of the most extensively cultivated millets globally [ 83 ]. The utility of pearl millet varies, ranging from food and feed, through forage, fodder, building material, to brewing and biofuel, making this an important crop species for food and livelihood security for more than 500 million poor and nutritionally insecure people around the world [ 84 ]. It is a small-grained, highly cross-pollinated (due to its protogyny) C 4 field crop with excellent photosynthetic behavior, suitable for smallholder farming systems, and it belongs to the family Poaceae (Grass) and the subfamily Panicoideae .…”

“…Pearl millet grain is highly nutritious, which is evident from its high contents of proteins (8–60%), fats (3–4.6%), vitamins (A and B), carbohydrates (60–78%), and lysine (40% more than maize) [ 84 ]. It has low contents of starch, is high in fiber (1.2 g per 100g), and has higher micronutrient (iron and zinc) concentrations than rice, wheat, maize, and sorghum [ 92 , 93 ].…”