Pearl millet is a climate-resilient, nutritious crop with low input requirements that could provide economic returns in marginal agro-ecologies. In this study, we report quantitative trait loci (QTLs) for iron (Fe) and zinc (Zn) content from three distinct production environments. We generated a genetic linkage map using 210 F6 recombinant inbred line (RIL) population derived from the (PPMI 683 × PPMI 627) cross using genome-wide simple sequence repeats (SSRs). The molecular linkage map (seven linkage groups) of 151 loci was 3,273.1 cM length (Kosambi). The content of grain Fe in the RIL population ranged between 36 and 114 mg/Kg, and that of Zn from 20 to 106 mg/Kg across the 3 years (2014–2016) at over the three locations (Delhi, Dharwad, and Jodhpur). QTL analysis revealed a total of 22 QTLs for grain Fe and Zn, of which 14 were for Fe and eight were for Zn on three consecutive years at all locations. The observed phenotypic variance (R2) explained by different QTLs for grain Fe and Zn content ranged from 2.85 (QGFe.E3.2014–2016_Q3) to 19.66% (QGFe.E1.2014–2016_Q3) and from 2.93 (QGZn.E3.2014–2016_Q3) to 25. 95% (QGZn.E1.2014–2016_Q1), respectively. Two constitutive expressing QTLs for both Fe and Zn co-mapped in this population, one on LG 2 and second one on LG 3. Inside the QTLs candidate genes such as Ferritin gene, Al3+ Transporter, K+ Transporters, Zn2+ transporters and Mg2+ transporters were identified using bioinformatics approaches. The identified QTLs and candidate genes could be useful in pearl millet population improvement programs, seed, restorer parents, and marker-assisted selection programs.

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Biofortification of pearl millet (Pennisetum glaucum (L.) R. Br.) with improved iron (Fe) and zinc (Zn) will have great impact as it is an indispensable component of nutritional security of inhabitants of arid and semi-arid regions. Ten genotypes along with checks were evaluated in RBD in six locations during kharif, 2016 under rainfed conditions. Significant differences were observed in genotype, environment and genotype × environment interaction mean squares for grain Fe and Zn contents, indicating differential nutrient accumulation by the genotypes. The first two principal components obtained in AMMI analysis were significant and cumulatively explained the total variation were 81.47 % for Fe and 73.97 % for Zn. A positive and moderately high correlation (r=0.6) between Fe and Zn contents suggests good prospects of simultaneous improvement for both micronutrients. Among the ten genotypes, PPMI 953 was found to be more stable with high mean Fe (90 ppm) and Zn (59 ppm) contents. On crossing with designated A lines of pearl millet, the line PPMI 953 found to be restorer for A1 system with complete fertility restoration of F1 panicle of the cross, ICMA(1) 863 x PPMI 953 under bagged condition and resulting F1 with 78-84% fertility measured by seed setting % under bag. The F2 individuals showed 9:7 fertility-sterility ratio (χ 2 value=0.002, P value=0.964). The promising line, PPMI 953 may be used as source for further genetic improvement with respect to grain micronutrient content or can be directly used as male parent in development of high iron pearl millet hybrids.

Present investigation was carried out to study the mode of inheritance of fertility restoration for A4 cytoplasm using pollen fertility and seed set per cent as criterion in determining the fertile and sterile plants. Two CMS lines of A4 cytoplasm were crossed with two fertility restorers generating four F1 crosses, namely, ICMA 99111 x PPMI 1003, ICMA 99111 x PPMI 1087, ICMA 03999 x PPMI 1003 and ICMA 03999 x PPMI 1087, their F2s and backcross generations. All the F1s were completely fertile indicating complete fertility restoration. F2s and backcross generations were evaluated at IARI, New Delhi and IARI Regional Centre, Dharwad during summer 2017 and χ 2 test was applied to test the significance. At both the locations, all the F2 segregating populations fit well into a Mendelian ratio of 15:1 indicating digenic duplicate dominance of fertility restoring genes with χ 2 value of 0.82, 2.90, 0.04, 3.97, 4.86, 4.98, 0.02, 1.26, 3.15, 4.98, 3.15 and 0.02. The F2 hypothesis was verified with the observed frequency of segregating plants fitting well into 3:1 ration with χ 2 value of 5.45, 1.93, 4.93, 0.60, 2.83, 0.44, 4.94, 2.77, 3.33, 0.13, 4.08 and 1.51. It is further confirmation of the findings that fertility restoration is indeed governed by two duplicate genes. Association between pollen fertility and seed set per cent was significant and positive.

Knowledge on intra-specific genetic variation of an organism is important for its genetic improvement and conservation. In order to estimate genetic variation and relatedness in eleven tropical Sugar beet varieties we used randomly amplified polymorphic DNA (RAPD) markers. The RAPD analysis was performed using six decamer random primers, which amplified a total of 63 DNA fragments of which 43 (68.25%) were found polymorphic. The average polymorphic bands per primer was 7.17 and the overall gene diversity was 0.24. Among the 43 polymorphic loci studied, 2 were specific for 2K 310, 1 for Shubraha, 1 for Natura and 1 for HI-0473 varieties. Pair wise genetic distance and similarity indices were ranged from 0.12-0.51 and 66.73-92.91, respectively. Cauvery and 2K 310 were found to be the most distantly related with a higher genetic distance value (GD = 0.51) and lower similarity index (SI = 66.73), while Aranka and Serenada were the most closely related with their lower GD (0.12) and higher SI(92.91) values. In an unweighted pair group method of arithmetic mean dendrogram constructed on the basis of genetic distances, the eleven varieties grouped into two main clusters: 2K 310 alone was in one cluster whereas 10 other varieties grouped into a major cluster. This indicates that 2K 310 was distantly related with each of the other varieties. Distantly related varieties based on estimated genetic variation could be selected for future breeding program that could result in improvement of this crop.