Figures (7)  Tables (5)
    • Figure 1. 

      Effect of PGRs on regeneration of F. nilgerrensis leaf discs. (a) Effects of TDZ and 6-BA on callus formation at 25 d of culture. (b) Shoot regeneration curve cultured on A2C2 medium for different days. (c) Shoot regeneration process cultured on A2C2 medium for different days.

    • Figure 2. 

      Effects of CH concentrations and dark culture duration on the regeneration of F. nilgerrensis leaf discs at 45 d of culture. (a) The callus weight and shoot regeneration rates under different CH concentrations and dark culture duration. (b) The callus growth curve on the media containing 0.0 and 0.5 g·L−1 CH. (c) Effect of dark culture for 0, 7, 14, 21, and 28 d on regeneration. (d) The effect of 0.0, 0.2, 0.5 , 0.7, and 1.0 g·L−1 CH on regeneration. Bars indicate the S.E. of the means; different lowercase letters indicate significant differences among the treatments according to the LSD test (P < 0.05).

    • Figure 3. 

      Paraffin section observation of callus obtained from F. nilgerrensis leaf discs. (a) Type I callus (left) and its cells (right, black arrow), bar = 100 μm. (b) Type II callus (left) and its cells (right, black arrow), bar = 100 μm.

    • Figure 4. 

      Agrobacterium-mediated genetic transformation of F. nilgerrensis leaf discs.

    • Figure 5. 

      PCR analysis of GUS gene in transgenic lines. Lane M, DNA marker; Lanes 1–58, 58 putative transgenic lines; Lane WT, wild-type plant; Lane P, plasmid control; Lane H, ddH2O.

    • Figure 6. 

      Histochemical GUS staining of transgenic lines. (a) Wild-type plant. (b)–(d) PCR-positive transgenic plants.

    • Figure 7. 

      Transformants regeneration on medium with Kan. (a) Leaf regeneration of PCR-positive transgenic lines under Kan selective pressure. (b) Non-transformed plants (control).

    • Media codeConcentration (mg·L−1)Callus induction rate (%)Shoot regeneration rate (%)Shoot no. per explant
      TDZBAIBA
      A1C110.121.1 ± 1.91 i9.1 ± 2.08 j0.11 ± 0.04 gh
      A1C210.294.2 ± 2.14 ab37.8 ± 1.91 e0.40 ± 0.09 e
      A1C310.361.1 ± 1.91 e0.0 ± 0.00 l0.0 ± 0.00 i
      A2C120.180.0 ± 2.00 c79.0 ± 3.60 c1.47 ± 0.08 c
      A2C220.297.8 ± 0.57 a97.3 ± 0.58 a2.52 ± 0.09 a
      A2C320.364.5 ± 3.87 de4.4 ± 1.93 k0.07 ± 0.03 hi
      A3C130.125.6 ± 1.96 h17.8 ± 1.91 h0.19 ± 0.02 fg
      A3C230.292.1 ± 1.82b89.5 ± 0.50 b1.96 ± 0.07 b
      A3C330.362.2 ± 3.89 e20.3 ± 0.58 g0.25 ± 0.09 f
      A4C140.167.8 ± 1.91 d0.0 ± 0.00 l0.0 ± 0.00 i
      A4C240.245.6 ± 1.96 g0.0 ± 0.00 l0.0 ± 0.00 i
      A4C340.37.1 ± 2.54 j0.0 ± 0.00 l0.0 ± 0.00 i
      B1C110.15.6 ± 1.93 j0.0 ± 0.00 l0.0 ± 0.00 i
      B1C210.25.6 ± 1.93 j0.0 ± 0.00 l0.0 ± 0.00 i
      B1C310.327.8 ± 1.91 h0.0 ± 0.00 l0.0 ± 0.00 i
      B2C120.127.8 ± 1.91 h0.0 ± 0.00 l0.0 ± 0.00 i
      B2C220.247.7 ± 1.31 fg14.3 ± 2.31 i0.13 ± 0.05 gh
      B2C320.367.8 ± 1.91 d66.7 ± 3.51 d0.6 ± 0.10 d
      B3C130.125.2 ± 2.54 h0.0 ± 0.00 l0.0 ± 0.00 i
      B3C230.24.5 ± 1.91 j0.0 ± 0.00 l0.0 ± 0.00 i
      B3C330.350 ± 3.30 f34.4 ± 1.96 f0.35 ± 0.08 e
      B4C140.15.6 ± 1.91 j0.0 ± 0.00 l0.0 ± 0.00 i
      B4C240.28.9 ± 5.06 j0.0 ± 0.00 l0.0 ± 0.00 i
      B4C340.38.3 ± 1.67 j0.0 ± 0.00 l0.0 ± 0.00 i
      Values represent mean ± SE; Different lowercase letters indicate significant differences among treatments according to the LSD test (P < 0.05).

      Table 1. 

      Effect of different PGRs on regeneration of F. nilgerrensis leaf discs at 45 d of culture.

    • CH concentration (g·L−1)No. of leaf discsRate of callus induction (%)Rate of Type I callus (%)Rate of Type II callus (%)
      0.06075.56 ± 0.96 c6.11 ± 0.96 e69.44 ± 0.96 a
      0.26091.11 ± 0.96 b81.11 ± 0.96 b10.00 ± 1.67 d
      0.56096.67 ± 1.67 a87.23 ± 1.93 a9.44 ± 1.93 d
      0.76071.11 ± 1.92 d21.67 ± 1.67 c49.45 ± 2.54 b
      1.06062.78 ± 0.96 e17.22 ± 0.96 d45.56 ± 1.93 c
      Values represent mean ± SE; Different lowercase letters indicate significant differences among treatments according to the LSD test ( P < 0.05).

      Table 2. 

      The rates of Type I and II callus on the medium with different CH concentrations of F. nilgerrensis leaf discs at 45 d of culture.

    • Kan concentration (mg·L−1)No. of leaf discsRate of regeneration (%)
      06098.32 ± 2.01a
      56051.36 ± 1.62b
      10600.08 ± 0.01c
      15600.00c
      Values represent mean ± SE; Different lowercase letters indicate significant differences among treatments according to the LSD test (P < 0.05).

      Table 3. 

      The regeneration rates in different Kan concentrations of F. nilgerrensis leaf discs at 45 d of culture.

    • Kan concentration
      (mg·L−1)
      No. of infected explantsRate of resistant shoot regeneration (%)
      at 65 d post-infection
      Percentage of transformation (%)
      at 130 d post-infection
      106024.74 ± 0.62a10.98 ± 0.13a
      206010.25 ± 0.18b9.22 ± 0.20b
      30603.33 ± 0.14c3.22 ± 0.25c
      40601.67 ± 0.01d1.67 ± 0.01d
      50600.00e0.00e
      Values represent mean ± SE; Different lowercase letters indicate significant differences among treatments according to the LSD test (P < 0.05).

      Table 4. 

      Effect of Kan concentrations on Agrobacterium-mediated transformation of F. nilgerrensis leaf discs.

    • ProcedureMedia compositionDuration
      Agrobacterium infectionMS liquid medium, 100 μmol·L−1 AS, 5 g·L−1 glucose and 15 g·L−1 sucrose10 min
      Co-cultureMS, 2.0 mg·L−1 TDZ, 0.2 mg·L−1 IBA, 0.5 g·L−1 CH, 7 g·L−1 agar, 5 g·L−1 glucose and 30 g·L−1 sucrose3 d
      Delayed-selection cultureMS, 2 mg·L−1 TDZ, 0.2 mg·L−1 IBA, 0.5 g·L−1 CH, 7 g·L−1 agar, 30 g·L−1 sucrose, 250 mg·L−1 Tim and 250 mg·L−1 Cef4 d
      Selection and regeneration cultureMS, 2.0 mg·L−1 TDZ, 0.2 mg·L−1 IBA, 0.5 g·L−1 CH, 7 g·L−1 agar, 30 g·L−1 sucrose, 250 mg·L−1 Tim, 250 mg·L−1 Cef and 10/20 mg·L−1 Kan60 d
      Shoot elongation cultureMS, 2.0 mg·L−1 TDZ, 0.2 mg·L−1 IBA, 0.5 g·L−1 CH, 7 g·L−1 agar, and 30 g·L−1 sucrose, 250 mg·L−1 Cef and 10 mg·L−1 Kan60−90 d
      Rooting culture1/2 MS, 0.1 mg·L−1 IBA, 15 g·L−1 sucrose and 5 g·L−1 agar30 d

      Table 5. 

      Composition of media used for genetic transformation of F. nilgerrensis leaf discs.