Development of Maize Hybrids With Enhanced Vitamin-E, Vitamin-A, Lysine, and Tryptophan Through Molecular Breeding

• Main Authors: Abhijit K. Das, Munegowda M. Gowda, Vignesh Muthusamy, Rajkumar U. Zunjare, Hema S. Chauhan, Aanchal Baveja, Vinay Bhatt, Gulab Chand, Jayant S. Bhat, Satish K. Guleria, Supradip Saha, Hari S. Gupta, Firoz Hossain
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2021-07-01
• Series: Frontiers in Plant Science
• Subjects: maize; biofortication; nutrition; marker-assist selection; hybrid; DUS traits
• Online Access: https://www.frontiersin.org/articles/10.3389/fpls.2021.659381/full

Malnutrition is a widespread problem that affects human health, society, and the economy. Traditional maize that serves as an important source of human nutrition is deficient in vitamin-E, vitamin-A, lysine, and tryptophan. Here, favorable alleles of vte4 (α-tocopherol methyl transferase), crtRB1 (β-carotene hydroxylase), lcyE (lycopene ε-cyclase), and o2 (opaque2) genes were combined in parental lines of four popular hybrids using marker-assisted selection (MAS). BC1F1, BC2F1, and BC2F2 populations were genotyped using gene-based markers of vte4, crtRB1, lcyE, and o2. Background selection using 81–103 simple sequence repeats (SSRs) markers led to the recovery of recurrent parent genome (RPG) up to 95.45%. Alpha (α)-tocopherol was significantly enhanced among introgressed progenies (16.13 μg/g) as compared to original inbreds (7.90 μg/g). Provitamin-A (proA) (10.42 μg/g), lysine (0.352%), and tryptophan (0.086%) were also high in the introgressed progenies. The reconstituted hybrids showed a 2-fold enhancement in α-tocopherol (16.83 μg/g) over original hybrids (8.06 μg/g). Improved hybrids also possessed high proA (11.48 μg/g), lysine (0.367%), and tryptophan (0.084%) when compared with traditional hybrids. The reconstituted hybrids recorded the mean grain yield of 8,066 kg/ha, which was at par with original hybrids (mean: 7,846 kg/ha). The MAS-derived genotypes resembled their corresponding original hybrids for the majority of agronomic and yield-related traits, besides characteristics related to distinctness, uniformity, and stability (DUS). This is the first report for the development of maize with enhanced vitamin-E, vitamin-A, lysine, and tryptophan.