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Subject: Biotechnology and molecular Biology × Author: . Kunal × Start date: 1980 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Molecular Screening of maize genotypes for lysine, tryptophan and β-carotene using functional markers
    (CCSHAU, Hisar, 2023-07) . Kunal; Yashveer, Shikha
    Maize is the 3rd most significant cereal crop after wheat and rice with high nutritional value. But it is deficient in certain nutrients like essential amino acids lysine, tryptophan and β- carotene. Presence of recessive allele opaque-2 linked with SSR markers umc1066, phi112, phi057 leads to high lysine and tryptophan content. Similarly, presence of crtRB1 gene linked with crtRB1 marker increase β-carotene content. Therefore, this study was aimed to screen opaque-2 and crtRB1 genes in 25 maize inbred lines using these functional markers. These maize inbred lines were grown in greenhouse and DNA was isolated using CTAB method. PCR was performed using umc1066, phi112, phi057 and crtRB1 markers.In addition to this thirty one more markers were used for genetic diversity analysis. Analysis of PCR products was done using UV gel documentation system. Genetic diversity analysis was performed using NTSYS-pc software and high degree of polymorphism was found ranging from 0.37-0.80 and heterozygosity ranging from 0.49 to 0.84. Biochemical estimation of lysine, tryptophan and β- carotene content was done using maize flour. The relation between the amplicon size of PCR product and biochemical estimated content was drawn. It was found that the inbred line LM-17 with the favourable allele 153bp using phi112, 144bp using umc1066, 157bp using phi057 had the highest lysine and tryptophan content. The inbred line HKI-327T with favorable allele (296+543) using crtRB1 marker had the highest β-carotene content (19.86 ppm). The best possible combination is using the LM-17 inbred line because it is having highest lysine content (0.44%) and high tryptophan content (0.20%). In the similar way to increase β-carotene content, HKI-327T is a promising donor line having the highest β carotene content that can be utilized in marker-assisted breeding for introgression of trait for enhanced provitamin A into agronomically superior lines by tracking the favourable alleles. The pyramiding of both these genes with other genes responsible for enhancing the nutritional value of elite maize varieties can provide a novel strategy for biofortification programmes. Thus, this study helps to pave the ways to combat the problem of nutritional deficiency and hidden hunger.