Multi-Environment Quantitative Trait Loci Mapping for Grain Iron and Zinc Content Using Bi-parental Recombinant Inbred Line Mapping Population in Pearl Millet

Abstract

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.

Mapping quantitative trait loci and predicting candidate genes for Striga resistance in maize using resistance donor line derived from Zea diploperennis

“…The ICIM approach utilizes a strategy in which a stepwise regression is firstly performed, so markers with significant effect on QTL are selected. ICIM-ADD method was used with the multi-environmental model built in QTL IciMapping ( Li et al, 2015 ; Singhal et al, 2021 ). The parameters of QTL analysis were set as follows: logarithm of odds (LOD) = 1,000 permutations, step = 1 cM, and PIN = .001.…”

Potential of underutilized crops to introduce the nutritional diversity and achieve zero hunger

“…Marker-assisted breeding is extensively utilized in staple crops and has begun to be employed in some of the underutilized crops including barley, cassava, millets, pigeon pea, grass pea, peanuts, and some perennial plants. Recently, marker-trait association studies targeting nutritional traits have been carried out in some of the nutritionally rich underutilized crops (Nida et al 2021;Singhal et al 2021;Jaiswal et al 2019). However, it remains to be performed in a large number of orphan crops.…”

Stage Specific Comparative Transcriptomic Analysis to Reveal Gene Networks Regulating Iron and Zinc Content in Pearl Millet [Pennisetum Glaucum (L.) R. Br.]

“…The iron concentration in the genotype PPMI 953 is su cient enough to ful ll the desired iron concentration of daily human need [35]. Ample work has been carried to enhance iron and zinc content in pearl millet [36][37][38][39][40][41][42][43], however little or negligible work has been carried out to understand the mechanism or pathways involved in high Fe and Zn containing genotypes.…”