Browsing by Person "Bauer, Eva"

Now showing 1 - 2 of 2

Discovery of beneficial haplotypes for complex traits in maize landraces
(2020) Mayer, Manfred; Hölker, Armin C.; González-Segovia, Eric; Bauer, Eva; Presterl, Thomas; Ouzunova, Milena; Melchinger, Albrecht E.; Schön, Chris-Carolin
Genetic variation is of crucial importance for crop improvement. Landraces are valuable sources of diversity, but for quantitative traits efficient strategies for their targeted utilization are lacking. Here, we map haplotype-trait associations at high resolution in ~1000 doubled-haploid lines derived from three maize landraces to make their native diversity for early development traits accessible for elite germplasm improvement. A comparative genomic analysis of the discovered haplotypes in the landrace-derived lines and a panel of 65 breeding lines, both genotyped with 600k SNPs, points to untapped beneficial variation for target traits in the landraces. The superior phenotypic performance of lines carrying favorable landrace haplotypes as compared to breeding lines with alternative haplotypes confirms these findings. Stability of haplotype effects across populations and environments as well as their limited effects on undesired traits indicate that our strategy has high potential for harnessing beneficial haplotype variation for quantitative traits from genetic resources.
Genetic variation for cold tolerance in two nested association mapping populations
(2023) Revilla, Pedro; Butrón, Ana; Rodriguez, Víctor Manuel; Rincent, Renaud; Charcosset, Alain; Giauffret, Catherine; Melchinger, Albrecht E.; Schön, Chris-Carolin; Bauer, Eva; Altmann, Thomas; Brunel, Dominique; Moreno-González, Jesús; Campo, Laura; Ouzunova, Milena; Álvarez, Ángel; Ruíz de Galarreta, José Ignacio; Laborde, Jacques; Malvar, Rosa Ana
Cold reduces maize (Zea mays L.) production and delays sowings. Cold tolerance in maize is very limited, and breeding maize for cold tolerance is still a major challenge. Our objective was to detect QTL for cold tolerance at germination and seedling stages. We evaluated, under cold and control conditions, 919 Dent and 1009 Flint inbred lines from two nested association mapping designs consisting in 24 double-haploid populations, genotyped with 56,110 SNPs. We found a large diversity of maize cold tolerance within these NAM populations. We detected one QTL for plant weight and four for fluorescence under cold conditions, as well as one for plant weight and two for chlorophyll content under control conditions in the Dent-NAM. There were fewer significant QTL under control conditions than under cold conditions, and half of the QTL were for quantum efficiency of photosystem II. Our results supported the large genetic discrepancy between optimal and low temperatures, as the quantity and the position of the QTL were very variable between control and cold conditions. Furthermore, as we have not found alleles with significant effects on these NAM designs, further studies are needed with other experimental designs to find favorable alleles with important effects for improving cold tolerance in maize.