M. Fernanda Dreccer, Bethany Macdonald, Claire A. Farnsworth, M. Valeria Paccapelo, Mary Anne Awasi, Anthony G. Condon, Kerrie Forrest, Ian Lee Long & C. Lynne McIntyre

Theoretical and Applied Genetics May 2022; vol. 135: 1685–1703

Key message

Low-lodging high-yielding wheat germplasm and SNP-tagged novel alleles for lodging were identified in a process that involved selecting donors through functional phenotyping for underlying traits with a designed phenotypic screen, and a crossing strategy involving multiple-donor × elite populations.

Abstract

Lodging is a barrier to achieving high yield in wheat. As part of a study investigating the potential to breed low-lodging high-yielding wheat, populations were developed crossing four low-lodging high-yielding donors selected based on lodging related traits, with three cultivars. Lodging was evaluated in single rows in an early generation and subsequently in plots in 2 years with contrasting lodging environment. A large number of lines lodged less than their recurrent parents, and some were also higher yielding. Heritability for lodging was high, but the genetic correlation between contrasting environments was intermediate-low. Lodging genotypic rankings in single rows did not correlate well with plots. Populations from the highest lodging background were genotyped (90 K iSelect BeadChip array). Fourteen markers on nine chromosomes were associated with lodging, differing under high- versus low-lodging conditions. Of the fourteen markers, ten were found to co-locate with previously identified QTL for lodging-related traits or at homoeologous locations for previously identified lodging-related QTL, while the remaining four markers (in chromosomes 2D, 4D, 7B and 7D) appear to map to novel QTL for lodging. Lines with more favourable markers lodged less, suggesting value in these markers as a selection tool. This study demonstrates that the combination of donor functional phenotyping, screen design and crossing strategy can help identify novel alleles in germplasm without requiring extensive bi-parental populations.

See: https://link.springer.com/article/10.1007/s00122-022-04063-6

Fig. 2: Probability of lodging (a) and lodging angle (deviation from vertical) (b) for BC lines that showed lodging when grown in 2016 single-bordered rows. Values are total genetic effects centred around the experiment mean. Black lines indicate trait values for the recurrent parents, and crosses indicate trait values for the donors