Figures (5)  Tables (7)

    • Figure 1. 

      Flowering phenotype of parents and their F1 plant under low-light stress.

    • Figure 2. 

      Frequency distribution of (a) FFT and (b) FMT in the F2 population.

    • Figure 3. 

      The LOD value distribution of QTL loci for the FFT in the F2 population.

    • Figure 4. 

      The LOD value distribution curve of QTL site of the FMT in the F2 population.

    • Figure 5. 

      (a) Quantitative trait loci curve for cucumber FFT in F2:3 populations (green) and F2 (red). The filtering threshold was set as logarithm of the odds > 2.5. (b) Linkage map of Chr.1 the final FFT mapping interval in cucumber genome based on F2:3 family populations.

    • Traits WI (P1) M14 (P2) F1
      FFT (d) 55.0 ± 1.12c 68.0 ± 1.12a 60.0 ± 5.10b
      FMT (d) 46.0 ± 2.11c 61.0 ± 3.24a 54.0 ± 10.08b
      FFT: the first female flowering time; FMT: the first male flowering time; P1: parental line1; P2: parental line2.

      Table 1. 

      The flowering phenotype of different low-light tolerance cucumber lines under low-light stress.

    • Traits Range Mean (d) SD Kurtosis
      (SEK)      		 Skewness
      (SES)      		 CV
      FFT 49~90 60.1 ± 7.081 7.913 3.186 1.171 13.166
      FMT 44~70 55.1 ± 6.005 6.213 0.521 0.413 11.285
      SD: Standard deviation; CV, The coefficient of variation. CV = SD/Mean.

      Table 2. 

      Phenotype and variation analysis of cucumber flowering in the F2 population.

    • 1st order
      parameters      		Estimate2nd order
      parameters      		Estimate
      FFTFMTFFTFMT
      da0.000−13.063σ2p34.74135.429
      db0.000−10.178σ2mg20.67810.090
      ha5.113/σ2pg0.00020.661
      hb9.001/h2mg (%)59.5 228.48
      i−5.113/h2pg (%)00.0 058.33
      jab4.160/
      jba0.000/
      l−9.099/
      [d]9.52926.828
      [h]−6.79713.262
      [h]/[d]−0.7130.450
      da: Additive effect of the first pair of main genes; db: Additive effect of the second pair of main genes; ha: Dominant effect of the first pair of main genes; hb: Dominant effect of the second pair on the main gene; [d]: Polygenic additive effectivity; [h]: Multigene dominant effector value; [h]/[d]: Dominant potential-energy ratio; σ2p: Phenotypic variance; σ2mg: Main gene variance; σ2pg: Polygenic variance; h2mg (%): Main gene heritability rate; h2pg (%): polygenic inheritance rate.

      Table 3. 

      Estimates of the first- and second-order genetic parameters of flowering time.

    • QTLs Chr. Marker no. Start position (bp) End position (bp) Peak position (cM) Max LOD ADD DOM PVE (%) Gene no.
      QFFT1.1 1 4 4,094,997 4,101,608 27.658 3.825 9.087 −4.383 10.22 1
      QFFT6.1 6 1 / / 41.620 3.817 −4.473 −9.388 10.03 /
      QFMT6.1 6 5 2,045,652 2,525,003 13.103 3.320 −2.123 −2.036 12.61 42
      QTL, quantitative trait loci; LOD, Limit of detection; Chr., Chromosome; Max LOD, Maximum limit of detection; ADD, additive effect; DOM, dominance effect; PVE, the contribution rate.

      Table 4. 

      QTLs effect analysis and the number of candidate genes of FFT and FMT in cucumber under low-light stress.

    • FFT Gene ID Function annotation
      1. CsGy1G030020 F-box protein
      2. CsGy1G030030 Tyrosine N-monooxygenase
      3. CsGy1G030040 Isoleucine N-monooxygenase 1-like
      4. CsGy1G030050 Isoleucine N-monooxygenase 1-like
      5. CsGy1G030060 Isoleucine N-monooxygenase 1-like
      6. CsGy1G030070 Isoleucine N-monooxygenase 1-like
      7. CsGy1G030120 Regulator of chromosome condensation (RCC1) family with FYVE zinc finger domain-containing protein
      8. CsGy1G030160 Pectin lyase-like superfamily protein
      9. CsGy1G030170 Polygalacturonase
      10. CsGy1G030260 AT-hook motif nuclear-localized protein
      11. CsGy1G030270 non-specific phospholipase C2
      12. CsGy1G030290 Telomerase-binding protein EST1A
      13. CsGy1G030300 Rho GTPase-activating protein 7
      14. CsGy1G030350 Histone deacetylase
      15. CsGy1G030360 Heat stress transcription factor B-4b-like
      Genes were blast in cucumber (Gy14) genome V2.1 (http://cucurbitgenomics.org/v2).

      Table 5. 

      Functional annotation of candidate genes of FFT.

    • FMT Gene ID Function annotation
      1. CsGy6G002770 Somatic embryogenesis receptor kinase 1(SERK1)
      2. CsGy6G002910 Protein PRD1 isoform X1
      3. CsGy6G002920 Protein TIC 22-like, chloroplastic isoform X1
      4. CsGy6G002930 Histone-lysine N-methyltransferase
      5. CsGy6G002980 MACPF domain-containing protein
      6. CsGy6G002990 Chloroplastic
      7. CsGy6G003000 Sn1-specific diacylglycerol lipase beta isoform X4
      8. CsGy6G003020 Vesicle transport protein
      9. CsGy6G003040 WW domain-containing protein
      10. CsGy6G003050 Clathrin interactor EPSIN 3-like isoform X2
      11. CsGy6G003060 STRUBBELIG-receptor family 5
      Genes were blast in cucumber (Gy14) genome V2.1 (http://cucurbitgenomics.org/v2).

      Table 6. 

      Functional annotation of candidate genes of FMT.

    • Gene ID Chr. Position WI M14 Effect type ALT proportion
      CsGy1G030350 Gy14Chr.1 28614154 C G Promoter 40.25%
      Gy14Chr.1 28615565 C T Promoter 40.00%
      Gy14Chr.1 28631912 G T Splice region variant and intron variant 38.00%
      Gy14Chr.1 28634739 T G Missense variant 38.00%
      Gy14Chr.1 28634748 G T Missense variant 40.00%
      CsGy1G030020 Gy14Chr.1 28181730 T C Splice region variant and intron variant 14.04%
      CsGy6G002770 Gy14Chr.6 2129884 CACATAG C Indel 10.75%
      Gy14Chr.6 2122291 A G Promoter 10.12%
      Gy14Chr.6 2129636 A G Splice region variant and intron variant 10.50%
      CsGy6G002920 Gy14Chr.6 2261766 G A Promoter 12.38%

      Table 7. 

      Analysis of parental variation sites and natural population gene diversity of four candidate genes.