Identification of QTL Associated with Agro-Morphological and Phosphorus Content Traits in Finger Millet under Differential Phosphorus Supply via Linkage Mapping

Abstract

Finger millet (Eleusine coracana (L.) Gaertn.) is one of the most important cereal crops for people in Asia and Africa. It supplies energy and nutrients for all people, particularly poor people in these continents. Phosphorus (P) is an essential macronutrient for plant growth and grain quality, so an adequate amount of P is required for healthy plant life. There is considerable evidence that P deficiency affects the growths and yields of all cereals, including finger millet. The present study aimed at identifying the quantitative trait loci (QTL) for various agro-morphological and P-content traits under low P (LP) and high P (HP) conditions through linkage mapping. Two cultivars, IE-2606 (low-P-susceptible) and PR-202 (low-P-tolerant) were used to develop 100 recombinant inbred lines (RILs). In total, 55 QTL, associated with various agro-morphological (primary root length (PRL), shoot fresh weight (SFW), root fresh weight (RFW), shoot dry weight (SDW), root dry weight (RDW), and root hair density (RHD)) and P-content traits (inorganic phosphate content in shoots (PiS), inorganic phosphate content in roots (PiR), and total P content in shoots (TPS)) were detected under LP conditions. Similarly, 37 QTL for various agro-morphological (PRL, RFW, SDW, and root hair length (RHL)) and P-content traits (PiS, PiR, TPS, and total P content in roots (TPR)) were detected under HP conditions. Biotic and abiotic stress-responsive candidate genes linked to a few QTL were also identified. The identified QTL associated with agro-morphological and P-content traits in finger millet under P deficiency could be used in breeding programs to develop finger millet with better P use efficiency (PUE). Furthermore, improving finger millet growth and yield under LP soil will help to reduce Pi application and eutrophication, which may help to improve the lives of poor farmers and maintain sustainable environments in Asia and African countries.

Mineral nutrients in plants under changing environments: A road to future food and nutrition security

“…A total of 55 QTLs, associated with agro-morphological and P-content traits, were detected in finger millet under low P condition (Maharajan et al, 2023). Similarly, Gao et al (2020) identified several QTL for PUE and P acquisition efficiency and yield-related traits at the maturity stages in 128 RILs of barley under low P conditions (Gao et al, 2020).…”

“…A total of 55 QTLs, associated with agro‐morphological and P‐content traits, were detected in finger millet under low P condition (Maharajan et al., 2023). Similarly, Gao et al.…”

Role of Genome Sequences of Major and Minor Millets in Strengthening Food and Nutritional Security for Future Generations

“…Compared to other major cereals, QTL associated with improving nutrients' use and acquisition efficiencies have not been identified much in millets. Recently, more than 50 QTL associated with various agro-morphological, phosphorus contents in shoot and roots and biomass traits were identified in 100 RILs of finger millet using 101 SSR markers under low-and high-phosphate conditions [68]. The same group also identified eight QTL for root-and shoot-related traits under the same low-and high-phosphate conditions using 87 SSR markers in finger millet through association mapping [69].…”

Finger millet (Eleusine coracana) improvement: Challenges and prospects—A review

“…Studies at the University of Georgia have characterized a bi‐parental interspecific population (MD‐20 × Okhale 1) (Qi et al, 2018) to map for days to flowering, plant height, panicle number per plant and blast disease resistance (Pendergast et al, 2022), and colouration of stigma and anthers (Devos et al, 2023). A mapping population between IE‐2606 and PR‐202 consisting of 100 individuals was characterized for agro‐morphological traits and protein content, identifying several QTLs (Maharajan et al, 2023). Table 8 summarizes MTAs conducted in finger millet that used at least 100 genotypes and a minimum of 100 markers in the trait characterization.…”