Enhancing β-Carotene Concentration in Parental Lines of CO6 Maize Hybrid Through Marker-Assisted Backcross Breeding (MABB)

Abstract

Vitamin A deficiency (VAD) is a global health problem; many people around the world, especially children and pregnant women, are VAD deficient or insufficient. Maize is known as an important source of provitamin A for humans. Hence, enhancement of provitamin A carotenoids (pVAC) in maize varieties through breeding or biofortification is a good option for alleviating VAD in developing countries, especially India. So far, numerous maize hybrids have been developed in India. Among them, CO6, derived from UMI1200 × UMI1230, is a popular maize hybrid and adapted to different agro-climatic zones of India, especially Tamil Nadu, a southern state of India. However, CO6 is deficient for pVAC carotenoid β-carotene. Thus, the objectives of this study were to increase the β-carotene concentration in UMI1200 and UMI1230 and generate the β-carotene enriched hybrids through marker-assisted backcross breeding (MABB). For this purpose, the maize genotype HP467-15 was used as the donor for transferring the β-carotene gene, crtRB1 , into UMI1200 and UMI1230. In the MABB scheme, we used one gene-specific marker ( crtRB1 3′TE) and 214 simples sequence repeat (SSR) markers for foreground and background selection, respectively. As a result, six improved lines with recurrent parent genome recovery (RPGR) ranging from 90.24 to 92.42%, along with good agronomic performance, were generated. The β-carotene concentration of the improved lines ranged from 7.056 to 9.232 μg/g. Furthermore, five hybrid combinations were generated using improved lines and evaluated in a comparative yield trial (CYT) and multi-location trials (MLT) along with the original hybrid CO6 and commercial hybrids. It was revealed that ACM-M13-002 was a superior hybrid with a 7.3-fold increase in β-carotene concentration and with a comparable yield to CO6. In summary, the improved maize inbreds can be used as possible donors for the development of β-carotene-rich cultivars in maize breeding programs and the β-carotene enriched hybrid developed in this study will hold great promise for food and nutritional security.

Improvement of a Yairipok Chujak Maize Landrace from North Eastern Himalayan Region for β-Carotene Content through Molecular Marker-Assisted Backcross Breeding

“…The high degree of resemblance with their recurrent parent for the trait of plant height in the present study agreed with earlier reports of Mehta et al [ 25 ] when developing sweet corn hybrids for vitamin A fortification. The high rate of recurrent parent recovery in the BC 2 F 2 generation was also reported in previous studies [ 8 , 9 , 11 , 26 ]. The improved line CAUM66-54-9-12-24 recorded high β-carotene (8.711 μg/g) comparable to that of the donor parent (UMI285β + ) followed by the lines, viz., CAUM66-54-9-12-13 and CAUM66-54-9-12-11 which recorded 8.647 μg/g and 8.258 μg/g, respectively.…”

“…Hence, allele 1 is identified as a favorable allele that is responsible for the accumulation of a higher level of β-carotene in the maize endosperm. Many researchers used the gene-specific markers developed from the crtRB1 gene in MABC programs to increase the β-carotene content in popular elite varieties and hybrids [ 8 , 9 , 10 , 11 ]. In the NEHR of India, maize is the staple food crop and the local people cultivate the maize landraces and consume them as food.…”

Medium optimization and downstream process design for the augmented yield of β-Carotene using fungi Blakeslea trispora

“…Song et al (2018) reported the increase of acticity around 7.7% using modified corn omso-coating substrate for β-Carotene (Song et al , 2018). Natesan et al , 2020 have reported a method of increasing the concentration of β -Carotene through Marker-Assisted Backcross Breeding in CO 6 Maize hybrid.…”

Development of β-carotene, lysine, and tryptophan-rich maize (Zea mays) inbreds through marker-assisted gene pyramiding

“…Several studies in India and other parts of the world have successfully introgressed either crtRB1 or o2 into popular elite lines and improved the β-carotene, lysine, and tryptophan contents 24 – 30 . The common determinant in all the previous studies is the introgression of a single factor into an established variety.…”