title: Introgression of thecrtRB1gene into quality protein maize inbred lines using molecular markers.
abstract: Quality protein maize (QPM;Zea maysL.) has effectively enhanced levels of the amino acids, lysine, and tryptophan, over normal maize and provided balanced dietary protein for the health and development of monogastric animals and humans. However, as in normal maize, QPM varieties are low in provitamin A (ProVA), a precursor of vitamin A, which can lead to vitamin A deficiency in humans when maize is a significant part of their diet. In this study, maize inbred Hp321-1 carrying the favorable allelescrtRB1-5'TE-2andcrtRB1-3'TE-1that can enhance levels of ProVA, was used as donor for improving ProVA in QPM inbred lines CML161 and CML171. Functional markers for identifying the favorable allelescrtRB1-5'TE-2andcrtRB1-3'TE-1were used in foreground selection, and simple sequence repeat markers were used in background selection for the BC1F1, BC2F1, and BC2F2generations. The background recovery rates were 77.4 and 84.5 % for CML161 and CML171 populations, respectively, in the BC1F1generation, and 89.9 and 92.1 % in the BC2F2generation. With foreground and background selection, the mean ProVA concentration has been improved from 1.60 µg g-1in the parent of CML161 to 5.25 µg g-1in its BC2F3offspring, from 1.80 µg g-1in the parent of CML171 to 8.14 µg g-1in its BC2F3offspring while maintaining similar QPM characteristics of the recurrent parents. The success from this study offers maize breeders a procedure for increasing ProVA in QPM lines, which will greatly mitigate vitamin A deficiency and protein-energy malnutrition in developing countries.
authors.affiliation: Institute of Food Crops, Yunnan Academy of Agricultural Sciences (YAAS), Kunming, 650205 Yunnan Province China.
authors.forename: Li
authors.identifier: 0000-0002-1544-6502
authors.initials: L
authors.lastname: Liu
authors.affiliation: CIMMYT Yunnan, Institute of Food Crops, Yunnan Academy of Agricultural Sciences (YAAS), Kunming, 650205 Yunnan Province China.
authors.forename: Daniel
authors.initials: D
authors.lastname: Jeffers
authors.affiliation: Yunnan Tian Rui Seed Company, LTD., Kunming, 650205 Yunnan Province China.
authors.forename: Yudong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Institute of Food Crops, Yunnan Academy of Agricultural Sciences (YAAS), Kunming, 650205 Yunnan Province China.
authors.forename: Meiling
authors.initials: M
authors.lastname: Ding
authors.affiliation: Institute of Food Crops, Yunnan Academy of Agricultural Sciences (YAAS), Kunming, 650205 Yunnan Province China.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: Department of Plant Pathology, Kansas State University, Manhattan, KS 66506-5502 USA.
authors.forename: Manjit S
authors.initials: MS
authors.lastname: Kang
authors.affiliation: Institute of Food Crops, Yunnan Academy of Agricultural Sciences (YAAS), Kunming, 650205 Yunnan Province China.
authors.forename: Xingming
authors.initials: X
authors.lastname: Fan
keywords: Background selection; Foreground selection; Functional markers; Maize (Zea mays L.); Provitamin A; crtRB1 gene