Thumbnail Image

Thesis

Browse

20181
Reset filters
Subject: Agricultural Biotechnology × Author: Amandeep Kaur ×
Reset filters

Search Results

Now showing 1 - 1 of 1
  • Thumbnail Image
    ThesisItemOpen Access
    INTROGRESSION OF crtRB1 AND LcyE GENES FOR HIGH β-carotene INTO QUALITY PROTEIN MAIZE (QPM)
    (Punjab Agricultural University, Ludhiana, 2018) Amandeep Kaur; Malhotra, Pawan Kumar
    Maize (Zea mays L.) being the queen of cereals deficient in Vitamin A which causes the malnutrition and major health problems. Quality protein maize has enhanced level of the amino acids, lysine, and tryptophan over normal maize varieties. However, QPM varieties are low in provitamin A, a precursor of vitamin A which can lead to vitamin A deficiency in human. In the present investigation, the grain quality of QPM inbred is further enriched for β-carotene by introgressing of crtRB1 and LcyE gene through marker assisted backcross breeding. Rare natural genetic variation of crtRB1 and LcyE gene enhances β-carotene in the kernel by blocking its conversion to further components. Traditional yellow maize though contain high kernel carotenoids, but the concentration of provitamin A is quite low (<1.5µg/g) as compared to the recommended level (15µg/g). Development of biofortified maize enriched in provitamin A, lysine and tryptophan thus holds significant potential in the alleviation of micronutrients. Marker assisted stacking of crtRB1, LcyE and o2 were undertaken in the genetic background of QLM13, inbred of PMH1 hybrid. Foreground selection was carried out using gene-specific primers on BC2F1 population of QLM 13 and background selection was carried out using SSR markers to check the recovery of recurrent parent genome. The plants of favorable alleles (crtRB1 and LcyE) and 88.5-90.1% recurrent parent genome recovery were selected and selfed to generate BC2F2 population. Foreground selection was carried out on BC2F2 population using crtRB1 and LcyE gene-specific markers and plant carrying favorable homozygous allele were selfed to generate BC2F3 progenies. Quality analysis for determination of β-carotene and tryptophan analysis was carried out on BC2F3 progenies. The introgressed BC2F3 progenies possessed a high concentration of provitamin A (1.29–11.75 µg/g) as compared to recurrent parent QLM13 (4.69 µg/g). The selected lines of high beta-carotene and tryptophan content were crossed to reconstitute PMH1 hybrid. Introgressed inbred having contrast for pigmentation in glume base and silk with respective to recurrent parents possess great utility for registration and unambiguous identification in the field.