Inbreeding depression and performance of partially self-fertilized maize progenies in a top cross

Abstract

Information on the effect of endogamy and combining ability of inbred families is essential in hybrid maize (Zea mays L.) breeding programs. The objective of this study was to evaluate the effect of inbreeding in a maize population and the performance of top-cross hybrids from this population, with a broad genetic base tester. First, 110 S1 families were generated and established in the field along with families from the original population. The experiment was arranged in a randomized block design with three replicates, in 3.0 m plots with 15 plants. Traits of agronomic importance, inbreeding depression, and the general effect of dominance deviations were estimated the first stage. In the second stage, 69 inbred families (S2) with low inbreeding depression were evaluated by top-cross tests using the F2 generation of the commercial hybrid AG 6040 as tester. The same traits from the first stage were evaluated. Inbreeding depression in the first stage was higher for traits related to production, which indicates that the heterozygous loci contribute more to these traits, with the additive effects being less important. In the second stage, the best estimates of the general combining ability (GCA) for grain weight were found in progenies 51, 33, 17, 9, 3, and 67, showing good performance and good potential for use in breeding programs.

Mean components for choosing maize populations to extract inbred lines

“…The inbreeding depression (ID%) for the grain yield trait was, on an average, 30.89%, and it ranged from 17.42 to 46.09% for the hybrids AG1051 and RK3014, respectively (Table 7). Other results corroborate with the values obtained in this work (Oliveira et al, 2020;Somera et al, 2018).…”

“…When considering the contribution of the estimates for plant height, it is observed on an average, as a higher contribution of m+a (80.43%) in relation to d (19.57%) (Table 8). Similar results were reported by several authors demonstrating that this characteristic has a greater influence of additive effects than others (Oliveira et al, 2020;Somera et al, 2018;Viana et al, 2009).…”

Estimation of Inheritance Leaf Rust, Powdery Mildew, Yield and Yield Components in Barley through Generation Means Analysis

“…Results in Table 4a and b reflecting that dominance plays greater role in inheritance of most studied traits, so selection for improvement these traits could be effective in late generations. Additive x additive gene effect was more effective than dominance x dominance and additive x dominance reflecting the important of this type of gene action, similar results were obtained by Mansour [22], Andreia et al [24] and Attiq et al [21]. Bojan et al [28] reported that, dominant was more important than additive component.…”

Keragaan Komponen Hasil dan Keragaman Genotipe Ubi Jalar Lokal Papua

“…Yen (1974) menyatakan bahwa di Tanah Papua terdapat kurang lebih 5.000 kultivar ubi jalar dengan keragaman tertinggi terdapat terutama di wilayah Pegunungan Tengah. Ubi jalar dapat tumbuh dan beradaptasi pada kondisi lingkungan yang beragam, itu sebabnya bisa ditemukan dari dataran rendah sampai dataran tinggi (Somera et al, 2018). Ubi jalar memiliki banyak variasi yang membedakan satu genotipe dengan genotipe lainnya.…”