Genetic Variability and Correlations in a Modified Endosperm Texture Opaque‐2 Maize Population¹

Abstract

To better understand the relationship between endosperm texture, protein quality, and other seed traits in modified endosperm (vitreous) opaque‐2 maize (Zea mays L.), estimates of additive and dominance variance, heritability, and genetic correlations were obtained for a population designated Disease Oil modified opaque‐2. Sixty S1 families were grown in 1977. In 1980, 240 S2 families (four from each S1 family) were evaluated. Families were measured for percent and degree of endosperm modification, 100 kernel weight, kernel density, plant height, percent lysine, percent protein, and lysine per 100 g of protein. All traits showed significant genetic variance. Heritability estimates were high to intermediate for all traits except kernel density. Additive genetic variance was significant and dominance variance nonsignificant for percent lysine and protein, lysine per 100 g protein and plant height. Dominance variance was significant and additive variance nonsignificant for endosperm modification, 100 kernel weight, kernel volume and density. Endosperm modification was negatively correlated with percent lysine, percent protein, and lysine per 100 g protein. Therefore, selection for endosperm modification should be accompanied by selection for lysine content to insure levels similar to non‐modified opaque‐2 material. Endosperm modification was highly positively correlated with kernel density.

Genetic analysis of tropical quality protein maize (Zea mays L.) germplasm

“…The QPM inbred lines used in this study were developed from conversion of a variety of mid-altitude normal endosperm inbred lines and OPVs to QPM and this explained the observed large genetic variability for various traits. This result is consistent with reports of genetic variability in tropical and temperate QPM germplasm (Spaner et al 1992;Vasal et al 1993a;Pixley and Bjarnason 1993;Bhatnagar et al 2004;Musila et al 2010;BaduApraku and Lum 2010;Badu-Apraku et al 2016) and in opaque-2 types (Motto et al 1978;Wessel-Beaver et al 1985).…”

Genetic control of kernel modification found in South African quality protein maize inbred lines

“…In modified 02 (mod-o2) kernels, modifier genes restore the endosperm to various degrees of normality. Several studies have shown that modified endosperm is quantitatively inherited (Motto, 1979;Sriwatanapongse et al, 1974;Ortega and Bates, 1983;Wessel-Beaver et al, 1985;Glover and Mertz, 1987).…”

Variation among and within S1 progenies of maize

“…Results of Wessel-Beaver et al (1985) showed a greater genetic variance among families versus within families for the traits of plant height, percent lysine, percent protein, and lysine per 100 grams of protein. All other traits showed greater genetic variances for the within families component.…”

“…In a more recent study, Wessel-Beaver et al (1985) estimated the variances among and within families derived from a modified opaque-2 maize population for endosperm modification, protein quality, and kernel traits. Evaluated material was obtained by selfing within 60…”

“…For traits with greater magnitudes of among family genetic variance, additive genetic variance was more important while dominance variance was more important for traits exhibiting a greater within family genetic variance. Wessel-Beaver et al (1985) concluded that considerable genetic variation existed in the population for most traits and endosperm modification appeared to be controlled by dominance genetic variance. From the results-of this study it would seem that variances among and within inbred families may be influenced by the triploid nature of the endosperm and its associated characteristics.…”