Investigating the genetic control of plant development in spring barley under speed breeding conditions

• Published in: Theoretical and applied genetics Vol. 137; no. 5; p. 115
• Main Authors: Rossi, Nicola, Powell, Wayne, Mackay, Ian J., Hickey, Lee, Maurer, Andreas, Pillen, Klaus, Halliday, Karen, Sharma, Rajiv
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-05-2024; Springer Nature B.V
• Subjects: Agriculture; Alleles; Barley; Biochemistry; Biomedical and Life Sciences; Biotechnology; Chromosome Mapping; Crops; Developmental plasticity; Flowering; Flowers - genetics; Flowers - growth & development; Gene mapping; Genes, Plant; Genetic control; Genotype; Genotypes; Hordeum - genetics; Hordeum - growth & development; Life Sciences; Maturity; Original; Original Article; Phenotype; Photoperiod; Photoperiods; Plant Biochemistry; Plant Breeding; Plant Breeding/Biotechnology; Plant Genetics and Genomics; Plant Proteins - genetics; Plant Proteins - metabolism; Polymorphism, Single Nucleotide; Quantitative Trait Loci
• ISSN: 0040-5752; 1432-2242
• DOI: 10.1007/s00122-024-04618-9

Key message
This study found that the genes, PPD-H1 and ELF3, control the acceleration of plant development under speed breeding, with important implications for optimizing the delivery of climate-resilient crops.
Speed breeding is a tool to accelerate breeding and research programmes. Despite its success and growing popularity with breeders, the genetic basis of plant development under speed breeding remains unknown. This study explored the developmental advancements of barley genotypes under different photoperiod regimes. A subset of the HEB-25 Nested Association Mapping population was evaluated for days to heading and maturity under two contrasting photoperiod conditions: (1) Speed breeding (SB) consisting of 22 h of light and 2 h of darkness, and (2) normal breeding (NB) consisting of 16 h of light and 8 h of darkness. GWAS revealed that developmental responses under both conditions were largely controlled by two loci:
PPDH-1
and
ELF3
. Allelic variants at these genes determine whether plants display early flowering and maturity under both conditions. At key QTL regions, domesticated alleles were associated with late flowering and maturity in NB and early flowering and maturity in SB, whereas wild alleles were associated with early flowering under both conditions. We hypothesize that this is related to the dark-dependent repression of
PPD-H1
by
ELF3
which might be more prominent in NB conditions. Furthermore, by comparing development under two photoperiod regimes, we derived an estimate of plasticity for the two traits. Interestingly, plasticity in development was largely attributed to allelic variation at ELF3. Our results have important implications for our understanding and optimization of speed breeding protocols particularly for introgression breeding and the design of breeding programmes to support the delivery of climate-resilient crops.