SSR-based and carotenoid diversity assessment of tropical yellow endosperm maize inbred lines

Abstract

Yellow endosperm maize can be used to reduce vitamin A deficiency among many pre-school children and women of reproductive age in sub-Saharan Africa. Assessment of the genetic diversity of tropical yellow endosperm maize inbred lines will have genetic gains in breeding design to develop lines with an enhanced level of provitamin A. We screened 122 tropical yellow endosperm maize inbred lines with 62 simple sequence repeat (SSR) markers and 51 SSR loci were polymorphic. We detected 190 alleles with an average of 3.72 alleles per locus, and polymorphic information content values among the inbred lines varied from 0.12 to 0.74 with an average of 0.43. Genetic distance (GD) values among all the pairs of the 122 inbred lines varied from 0.02 to 0.61 with an average of 0.41 for the SSR markers. The inbred lines exhibited a substantial level of genetic diversity. Genetic diversity was also evaluated using carotenoid data. The Euclidean GDs varied from 1.00 to 9.97 with an average of 3.81 for the carotenoid data. Cluster and principal coordinate analyses revealed clear separation of maize inbred lines into SSR-based groupings and carotenoid-based groupings. Cluster based on SSR markers were predominantly consistent with known pedigree data of the inbred lines. The correlation using Mantel's test between carotenoid-based GD estimates and SSR marker-based GD estimates gave a low r value (2 0.06). The grouping of lines will facilitate the selection of parental lines for making crosses to develop new lines with enhanced provitamin A content.

Breeding for provitamin A biofortification of maize (Zea mays L.)

“…Adeyemo, Menkir, Gedil and Omidiji () studied the genetic diversity in maize inbred lines using AFLP and SSR molecular markers. Results showed that the genetic distance (GD) was varied from 0.08 to 0.64 for AFLP markers and from 0.007 to 0.59 for SSR markers for pairwise interaction of inbred lines.…”

“…Correlations between carotenoid‐based clustering and molecular marker‐based clustering were not strong. It is recommended that molecular analysis be used for the selection of parents for biparental crosses, whereas GD be used for the selection of parents for broadening the genetic base (Adeyemo et al., ). Das and Singh () used SSR markers to dissect the molecular diversity in yellow maize genotypes, and observed that Jaccard's similarity coefficients were ranged from 0.17 to 0.97.…”

Assessment of Diversity among Tropical and Subtropical Maize Inbreds Based on Morphological Traits and Carotenoid Content

“…Such varieties could be used in the development of yellow endosperm maize varieties (Open Pollinated Varieties and hybrids) which possess genes for adaptation and superior agronomic performance and thus represent a good genetic base to breed tropical maize for high levels of pro-vitamin A carotenoids [12]. In two separate studies, [13] as well as [14] assessed the nature and extent of the genetic diversity among tropically adapted yellow endosperm maize inbred lines at the International Institute of Tropical Agriculture (IITA) maize breeding programme. In the first study, [13] noted the diversity of carotenoid contents among 38 tropically adapted yellow endosperm maize inbred lines while the second report [14] contained information on the nature of variability for different carotenoid contents among the newly developed 122 inbred lines and grouped into three major groups based on carotenoid contents.…”

Genetic diversity and population structure of farmers' maize varieties (<i>Zea mays</i> L.) from three selected states in Nigeria using SSR markers and their relationship with standard hybrids

“…Microsatellites (simple sequence repeats, SSR) are widely used to evaluate genetic diversity and population structure based on their multiallelic nature; they can produce many alleles per locus, abundance and are repeatable (Warburton et al, 2008). SSR markers have been applied to characterize the genetic relationships of yellow adapted tropical maize germplasm from IITA breeding programs in Nigeria (Adeyemo and Omidiji, 2014). Also, a number of previous studies have reported the genetic diversity, genetic relationship and population structure of diverse maize inbred lines, breeding materials and maize landraces from the different maize germplasm and breeding programs based on SSR data (Inghelandt et al, 2010;Zhi-zhai et al, 2010;Semagn et al, 2014;Bedoya et al, 2017).…”