Cucumber fruit-pedicel length matters for fruit form and has been proposed as a trait relevant to mechanized harvesting. A 2024 Scientific Reports study used an EMS-derived short-pedicel mutant to show that cytokinin status and cell number are strongly associated with pedicel length.
The long-pedicel line averaged 1.8 cm versus 0.3 cm in the mutant
A stable recessive short-pedicel line (CPS) was isolated after EMS mutagenesis of the South China-type cucumber CPL. On flowering day, CPL pedicels measured 1.8 ± 0.3 cm, whereas CPS averaged 0.3 ± 0.1 cm.
The main anatomical difference was cell number
Paraffin sections showed that the short pedicel was explained primarily by a much lower longitudinal cell number rather than simply smaller cells.
Cytokinin measurements and treatments supported the mechanism
Trans-zeatin nucleoside was significantly higher in CPL than CPS, and transcriptome analysis enriched cytokinin-synthesis-related pathways. Treating CPS with the cytokinin analogue 6-BA lengthened pedicels to 1.0 ± 0.2 cm, while lovastatin treatment shortened CPL pedicels to 0.8 ± 0.3 cm.
Together these data support cytokinin-dependent cell proliferation as a major regulator of pedicel length.
A single causal gene has not yet been established
The work identifies cytokinin-related genes and pathways but does not reduce the phenotype to one validated causal gene. Mechanized harvesting was also a breeding motivation, not a directly tested outcome. Mapping the causal mutation and testing yield, fruit quality and harvesting performance are still needed.
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Reference
- Yane S et al. Cytokinin-related genes regulate cucumber fruit pedicel length. Scientific Reports. 2024;14:23361. https://doi.org/10.1038/s41598-024-75186-7
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