Genetic analyses of kernel carotenoids in novel maize genotypes possessing rare allele of β-carotene hydroxylase gene

Abstract

Carotenoids are important micronutrients required by humans for growth and development. Yellow maize among cereals possesses sufficient carotenoids, and thus, it is important to genetically dissect such traits for proper utilization in breeding programme. Twenty-one maize hybrids generated using novel inbreds with rare allele of β-carotene hydroxylase (crtRB1) that enhances kernel β-carotene, were evaluated at two diverse maize growing locations. Lutein, zeaxanthin and β-cryptoxanthin were positively correlated, while β-carotene showed negative correlation with other carotenoids. Grain yield did not show association with carotenoids. Preponderance of additive gene action was observed for lutein, zeaxanthin, β-cryptoxanthin and β-carotene. Experimental hybrids were much superior for kernel β-carotene compared to commercial hybrids. Based on SCA effects, high yielding experimental hybrids were identified for provitamin A and non-provitamin A carotenoids. These novel hybrid combinations of maize possessing rare allele of crtRB1 hold promise in maize biofortification programme to alleviate vitamin A deficiency and degenerative diseases in humans.

Assessing Effect of Marker-Based Improvement of Maize Synthetics on Agronomic Performance, Carotenoid Content, Combining Ability and Heterosis

“…The observed significant GCA and SCA effects for grain yield and other agronomic traits in our study indicated the importance of both additive and non-additive gene effects in the inheritance of these traits [32]. Conversely, the significant GCA but non-significant SCA effects for provitamin A and most carotenoids indicated the predominance of additive gene effects in their inheritance, consistent with the results reported in other studies involving maize inbred lines [26,28,30,49,50]. This, however, contradicts with the results of [27,29] who reported the presence of additive and non-additive gene effects in the inheritance of Provitamin A while [31] reported the preponderance of non-additive gene effects in the inheritance of provitamin A and other carotenoids.…”

“…Understanding the effect of marker-based improvement of the two synthetics on their combining abilities for grain yield and other desirable agronomic traits as well as provitamin A carotenoids can provide useful information on the genetic control of these traits and facilitate the identification of suitable source populations for divergent parental lines with good general and specific combining abilities (GCA and SCA) to optimize expression of heterosis in hybrids. Few studies, mainly in maize inbred lines have reported combining ability for grain yield and provitamin A carotenoids [26][27][28][29]. However, the combining ability and heterosis for grain yield, agronomic traits and provitamin A carotenoids in maize synthetics improved using high throughput marker assisted recurrent selection has not been reported.…”

Recurrent selection method for improvement of lutein and zeaxanthin in orange waxy corn populations

“…In this study, most correlation coefficients among lutein, zeaxanthin, β-carotene, lutein+zeaxanthin+βcarotene and total carotenoids at immature stage were positive and significant, ranging from 0.67 to 0.94 at P ≤ 0.01 except for the correlation coefficients between zeaxanthin and lutein and between zeaxanthin and β-carotene. In previous studies in field maize, zeaxanthin was positively and significantly correlated with lutein (Muthusamy et al, 2015;Muthusamy et al, 2016). Different genetic materials might express the different correlations among these traits.…”

“…Cycle 2 had the highest lutein, zeaxanthin, β-carotene, lutein+zeaxanthin+βcarotene and total carotenoids at most locations except for zeaxanthin at Khon Kaen location, in which cycle 1 was highest. The positive responses would be due to sufficient genetic variations in pro-vitamin A, carotenoids (Suwarno et al, 2014;Senete et al, 2011), lutein, zeaxanthin and βcarotene (Muthusamy et al, 2016). Recurrent selection could increase carotenoids in maize (Senete et al, 2011).…”

Marker‐assisted introgression of rare allele of β‐carotene hydroxylase (crtRB1) gene into elite quality protein maize inbred for combining high lysine, tryptophan and provitamin A in maize

“…BC and BCX are the intermediate products of the carotenoid biosynthesis pathway, leading to the more synthesis of final non‐proA products (LUT and ZEA). This is the main reason of maize kernels possessing limited proA, although being abundant in other carotenoids (Muthusamy et al, ). The reduction in non‐proA carotenoids could be the reduction of CRTRB1 transcript acting in carotenoid biosynthesis.…”