Variance Components and Correlations between Doubled Haploid Lines from Two European Flint Landraces and Their Corresponding Testcrosses for Gibberella Ear Rot Resistance, Silking Time, and Plant Height in Maize

Félicien Akohoue,David Sewordor Gaikpa,Thomas Miedaner,Thomas Presterl,Bettina Kessel

doi:10.3390/agronomy11061039

Félicien Akohoue, David Sewordor Gaikpa + Show 3 more

Open Access

https://doi.org/10.3390/agronomy11061039

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Abstract

Predicting the resistance of hybrids from lines is a relevant approach for accelerating the improvement of disease resistance in hybrid breeding. In this study, genetic variation and covariation among 76 DH lines from two flint landraces, Kemater (KE) and Petkuser (PE), and their corresponding testcrosses (TC) were estimated for the first time for this material for Gibberella ear rot (GER), days to silking (DS), and plant height (PHT). Lines and TC were evaluated in four and two environments, respectively, under artificial infection with GER. TC were, on average, 42% less GER infected than their lines. TC matured 3–4 days earlier and were about 110 cm taller than the lines. GER resistance was 10% higher in KE lines and TC than PE lines and TC. Significant (p < 0.001) genotypic and genotype-by-environment interaction variances were found for all traits. Genotypic variances were generally smaller among TC than lines. Broad-sense heritability estimates were moderate to high for GER severity (0.56–0.82) and high for DS (0.78–0.88) and PHT (0.86–0.94) with higher values always observed in lines. Significant, moderate correlations between TC and line per se performance were found for GER resistance in both KE and PE (r = 0.37 and 0.55, respectively). For the two agronomic traits, correlations were higher (r = 0.59–0.76) than for GER resistance. Genomic prediction accuracies were moderate to high for GER resistance (r = 0.49–0.63) and generally higher for DS and PHT. In conclusion, a pre-selection of DH lines for GER resistance should be feasible; however, TC should be additionally tested on a later selection stage to aim for GER-resistant hybrid cultivars.

Highlights

Maize (Zea mays L.) is the most important cereal crop after wheat (Triticum aestivum L.)and rice (Oryza sativa L.) and is grown for food and feed across the world [1,2,3]
Gibberella ear rot (GER) severity was, on average, 10% higher in double haploid (DH) lines and TC of the PE population than DH lines and TC of the KE population in all environments (Table 1)
Our results revealed that DH lines of the KE population were, on average, more resistant to Gibberella ear rot (GER) than DH lines of the PE population

Summary

Introduction

Rice (Oryza sativa L.) and is grown for food and feed across the world [1,2,3] It is considered a major food source with a high contribution to food and nutrition security in diverse regions such as Africa, where the consumption ranges from 52 to 328 g/person/day [1,4]. Different types of toxigenic ear rots caused by Fusarium spp. occur depending on the geographical location and prevailing climate or weather [13]. In cooler regions, such as Europe, northern United States, Canada and some higher altitudes in Africa, Gibberella ear rot (GER) and Fusarium ear rots (FER) are the major types that infect greater proportions of maize. In Germany, Gibberella and Fusarium ear rot infections were recently reported as the most dominant disease in maize with their relative occurrence depending on temperature and humidity in the respective year [16]

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