Mapping grain iron and zinc content QTLs in an Iniadi-derived immortal population of pearl millet

Pearl millet is a climate-resilient nutritious crop requiring low inputs, and is capable of giving economic returns in marginal agro-ecologies. In this study, we report large effect iron (Fe) and zinc (Zn) content QTLs using DArT arrays and SSRs to generate a genetic linkage map using 317 RIL population derived from (ICMS 8511-S1-17-2-1-1-B-P03 ? AIMP 92901-S1-183-2-2-B-08) cross. The base map (7 LGs) of 196 loci was 964.2 cM (Haldane). AIMP 92901-S1-183-2-2-B-08 is a high grain Fe and Zn line, an Iniadi parent tracing its origin to the Togolese Republic, West Africa. QTL analysis revealed a large number of QTLs for grain iron (Fe) and zinc (Zn) content. The concentration of grain Fe in the RIL population ranged between 20 and 131 ppm, and Zn from 18-110 ppm. A total of 19 QTLs for Fe and Zn were detected, of which 11 were for Fe and 8 were for Zn. The portion of observed phenotypic variance explained by different QTLs for grain Fe and Zn concentrations varied between 9.0-31.9% (cumulative 74%) and 9.4-30.4% (cumulative 65%), respectively. Three large effect QTLs for both minerals were co-mapped in this population - one on Linkage group (LG) 1 and the remaining two on LG7. The favourable alleles for QTLs of both the mineral micronutrients were contributed by the male parent (AIMP 92901-deriv-08). Three putative epistasis interactions were observed for Fe while single digenic interaction was for Zn. The reported QTLs may be useful in marker-assisted selection programs for seed and restorer parent breeding and population improvement programs in pearl millet.authorsversionPeer reviewe

Genome-wide identification and characterization of NBLRR genes in finger millet (Eleusine coracana L.) and their expression in response to Magnaporthe grisea infection

Abstract Background The nucleotide binding site leucine rich repeat (NBLRR) genes significantly regulate defences against phytopathogens in plants. The genome-wide identification and analysis of NBLRR genes have been performed in several species. However, the detailed evolution, structure, expression of NBLRRs and functional response to Magnaporthe grisea are unknown in finger millet (Eleusine coracana (L.) Gaertn.). Results The genome-wide scanning of the finger millet genome resulted in 116 NBLRR (EcNBLRRs1-116) encompassing 64 CC-NB-LRR, 47 NB-LRR and 5 CCR-NB-LRR types. The evolutionary studies among the NBLRRs of five Gramineae species, viz., purple false brome (Brachypodium distachyon (L.) P.Beauv.), finger millet (E. coracana), rice (Oryza sativa L.), sorghum (Sorghum bicolor L. (Moench)) and foxtail millet (Setaria italica (L.) P.Beauv.) showed the evolution of NBLRRs in the ancestral lineage of the target species and subsequent divergence through gene-loss events. The purifying selection (Ka/Ks < 1) shaped the expansions of NBLRRs paralogs in finger millet and orthologs among the target Gramineae species. The promoter sequence analysis showed various stress- and phytohormone-responsive cis-acting elements besides growth and development, indicating their potential role in disease defence and regulatory mechanisms. The expression analysis of 22 EcNBLRRs in the genotypes showing contrasting responses to Magnaporthe grisea infection revealed four and five EcNBLRRs in early and late infection stages, respectively. The six of these nine candidate EcNBLRRs proteins, viz., EcNBLRR21, EcNBLRR26, EcNBLRR30, EcNBLRR45, EcNBLRR55 and EcNBLRR76 showed CC, NB and LRR domains, whereas the EcNBLRR23, EcNBLRR32 and EcNBLRR83 showed NB and LRR somains. Conclusion The identification and expression analysis of EcNBLRRs showed the role of EcNBLRR genes in assigning blast resistance in finger millet. These results pave the foundation for in-depth and targeted functional analysis of EcNBLRRs through genome editing and transgenic approaches

Characterization of the Pearl Millet Cultivation Environments in India: Status and Perspectives Enabled by Expanded Data Analytics and Digital Tools

The cultivation of pearl millet in India is experiencing important transformations. Here, we propose a new characterization of the pearl millet production environment using the latest available district level data (1998–2017), principal component analysis, and large-scale crop model simulations. Pearl millet cultivation environment can be divided in up to five environments (TPEs). The eastern part of the country (Rajasthan, Haryana, Uttar Pradesh) emerges as the only region where pearl millet cultivation has grown (+0.4 Kha/year), with important yield increase (+51 kg/ha/year), and potential surplus that are likely exported. Important reductions of pearl millet cultivated area in Gujarat (−4.5 Kha/year), Maharashtra and Karnataka (−4 Kha/year) are potentially due to economy-driven transition to other more profitable crops, such as cotton or maize. The potential rain increase could also accelerate this transition. With R2∈ [0.15–0.61], the tested crop models reflected reasonably well the pearl millet production system in the A1 (North Radjasthan) and AE1 (South Rajastan and Haryana) TPEs covering the largest area (66%) and production share (59%), especially after the use of a new strategy for environment and management parameters calibration. Those results set the base for in silico system design and optimization in future climatic scenarios