No abstract

Pearl millet is an important food crop in the arid and semi-arid tropical regions of Africa and Asia. These regions are home to millions of poor smallholder's households living in harsh agroecology and reported higher prevalence of malnutrition. . Indeed, pearl millet is one of the food crops they continue to grow for their food and nutritional security. Considering inherent high nutritional values and climate resilient nature (drought and heat), demand for pearl millet as food, beside valued for its Stover as a source of livestock fodder, is projected to grow strongly in Asia (India) and Africa (West and Central Africa). Iron (cause anemia) and zinc (cause stunting) deficiencies are widespread and serious public health problems worldwide, including India and Africa. Biofortification is a cost-effective and sustainable agricultural strategy to address this problem. Aim of this review is to provide current status and future directions of pearl millet biofortification for growing nutrition markets. Research on pearl millet has shown that large genetic variability (30-140 mg kg −1 Fe and 20-90 mg kg −1 Zn) available in this crop can be effectively utilized to develop high-yielding cultivars with high iron and zinc densities. Both Open -pollinated varieties (Dhanshakti and Chakti) and hybrids (ICMH 1202, ICMH 1203 and ICMH 1301) of pearl millet with high grain yield (>3.5 tons/ha in hybrids) and high levels of iron (70-75 mg kg −1 ) and zinc (35-40 mg kg −1 ) densities have been developed and released in India. Currently, India growing >70,000 ha of biofortified pearl millet, besides more pipeline hybrids and varieties are under various stage of testing at the national (India) and international (west Africa) trials for possible release. Biofortification program utilized the existing high-Fe lines identified from the mainstream program to serve the immediate objective of developing high-yielding and high-Fe hybrids. Genomic tools will be an integral part of biofortification breeding program particularly to use diagnostic markers and genomic selection for micronutrients. Several biofortified varieties and hybrids released in pearl millet. Till today, no markets to promote biofortified varieties and hybrids as no incentive price and such products aims to address food and nutritional security challenges simultaneously. The demand is likely to increase only after investment in crop breeding and integration into modern public distribution system, nutritional intervention schemes, private seed and food companies with strong mainstreaming nutritional policies. In the non-traditional regions, this will contribute to livestock and poultry feed industry as spill-over benefits to improve nutrition. The following sections of this review describing various aspects of breeding for increased market opportunity of this crop towards addressing micronutrient malnutrition.

Pearl millet is an important food crop in the arid and semi-arid tropical regions of Africa and Asia. Iron and zinc deficiencies are widespread and serious public health problems worldwide, including in India and Africa. Biofortification is a cost-effective and sustainable agricultural strategy to address this problem. The aim of this review is to provide the current biofortification breeding status and future directions of the pearl millet for growing nutrition markets. Research on the pearl millet has shown that a large genetic variability (30–140 mg kg−1 Fe and 20–90 mg kg−1 Zn) available in this crop can be effectively utilized to develop high-yielding cultivars with high iron and zinc densities. Open-pollinated varieties (Dhanashakti) and hybrids (ICMH 1202, ICMH 1203 and ICMH 1301) of pearl millet with a high grain yield and high levels of iron (70–75 mg kg−1) and zinc (35–40 mg kg−1) densities have been developed and released first in India. Currently, India is growing > 70,000 ha of biofortified pearl millet, and furthermore more pipeline cultivars are under various stages of testing at the national (India) and international (west Africa) trials for a possible release. Until today, no special markets existed to promote biofortified varieties and hybrids as no incentive price to products existed to address food and nutritional insecurity simultaneously. The market demand is likely to increase only after an investment in crop breeding and the integration into the public distribution system, nutritional intervention schemes, private seed and food companies with strong mainstreaming nutritional policies. The following sections describe various aspects of breeding and market opportunity for addressing micronutrient malnutrition.

Crop biofortification is increasingly being recognized as a cost-effective and sustainable approach to address the widespread micronutrient malnutrition arising from Fe and Zn deficiencies. Pearl millet as a cereal crop species has higher Fe density than all other major cereals. Earlier studies in pearl millet have shown that breeding lines, hybrid parents, improved populations and composites having high Fe and Zn densities were often based largely or entirely on iniadi pearl millet germplasm. In an attempt to identify additional sources of high Fe density in this group of germplasm, 297 accessions were screened using Perl's Prussian Blue staining, of which 191 accessions (118 from Togo, 62 from Ghana and 11 from Burkina Faso) were re-evaluated during the 2010 rainy and 2012 summer seasons using the inductively coupled plasma atomic emission spectroscopy method. On the basis of the mean performance over the two seasons (environments), large variability was observed for both Fe (51 -121 mg/kg) and Zn (46-87 mg/kg) densities. There was a highly significant and positive correlation between the two micronutrients (r ¼ 0.77, P , 0.01). Of these re-evaluated accessions, 49% had higher Fe density than the high-Fe control commercial cultivar ICTP 8203 (81 mg/kg), and most of these accessions also had Zn density $61 mg/kg (59 mg/kg for ICTP 8203). A total of 27 accessions (20 from Togo and seven from Ghana) having a Fe density of 95 -121 mg/kg (1 standard error of difference above that for ICTP 8203) and a Zn density of 59-87 mg/kg were selected as a valuable germplasm resource for genetic improvement of these two micronutrients in pearl millet.

Improving essential nutrient content in staple food crops through biofortification breeding can overcome the micronutrient malnutrition problem. Genetic improvement depends on the availability of genetic variability in the primary gene pool. This study was aimed to ascertain the magnitude of variability in a core germplasm collection of diverse origin and predict pearl millet biofortification prospects for essential micronutrients. Germplasm accessions were evaluated in field trials at ICRISAT, India. The accessions differed significantly for all micronutrients with over two-fold variation for Fe (34–90 mg kg−1), Zn (30–74 mg kg−1), and Ca (85–249 mg kg−1). High estimates of heritability (> 0.81) were observed for Fe, Zn, Ca, P, Mo, and Mg. The lower magnitude of genotype (G) × environment (E) interaction observed for most of the traits implies strong genetic control for grain nutrients. The top-10 accessions for each nutrient and 15 accessions, from five countries for multiple nutrients were identified. For Fe and Zn, 39 accessions, including 15 with multiple nutrients, exceeded the Indian cultivars and 17 of them exceeded the biofortification breeding target for Fe (72 mg kg−1). These 39 accessions were grouped into 5 clusters. Most of these nutrients were positively and significantly associated among themselves and with days to 50% flowering and 1000-grain weight (TGW) indicating the possibility of their simultaneous improvement in superior agronomic background. The identified core collection accessions rich in specific and multiple-nutrients would be useful as the key genetic resources for developing biofortified and agronomically superior cultivars.