Figures (9)  Tables (7)

    • Figure 1. 

      Parental materials of Lagerstroemia and Heimia species and cultivars.

    • Figure 2. 

      Pollen viability of Lagerstroemia and Heimia species and cultivars.

    • Figure 3. 

      Fruiting rate of three pollination combinations with Lagerstroemia as female parent treated with GA3 and 2,4-D. (a) L. fauriei × H. salicifolia; (b) 'Sarah's Favorit' × H. salicifolia; (c) 'Qianceng Feixue' × H. myrtifolia.

    • Figure 4. 

      Fruit morphology after distant hybridization. (a) Fruit and seeds of 'Qianceng Feixue' × H. myrtifolia (left) and 'Qianceng Feixue' × 'Sarah's Favorite' (right) 35 d after pollination. (b) Hybrid fruits of H. salicifolia × 'Qianceng Feixue' (left), and H. salicifolia × H. salicifolia (right) 20 d after pollination.

    • Figure 5. 

      The behavior of pollen tubes in different cross combinations. (a) Pollen tubes elongated downward 12 h after pollination in 'Sarah's Favorite' × H. salicifolia. (b) Few pollen tubes extend into the ovary 48 h after pollination in 'Sarah's Favorite' × H. salicifolia. (c) Pollen tubes were mostly confined to about 1/4 of the stigma in L. fauriei × H. salicifolia. (d) Few pollen tubes reached the base of pistil in L. fauriei × H. salicifolia. (e) Pollen tubes stretched 2 h after pollination in H. salicifolia × 'Dallas Red'. (f) A few pollen tubes entered the ovary 48 h after pollination in H. salicifolia × L. fauriei. (g) The main obstacle occurred at the base of the pistil 72 h after pollination in H. myrtifolia × L. fauriei. (h) Callose were produced in the style 12 h after pollination in 'Sarah's Favorite' × H. salicifolia. (i) A few pollens germinated 4 h after pollination in H. salicifolia × 'Sarah's Favorite' without mentor pollens. (j) Pollen failed to germinate in 4 h after pollination in 'Sarah's Favorite' × H. salicifolia without mentor pollens. Pt: Pollen tube. Pg: Pollen grain. Ca: Callose. Ou: Ovule.

    • Figure 6. 

      Embryo development in different cross combinations. (a) Embryos 25 d after open pollination in H. salicifolia. (b) Embryos 25 d after pollination in 'Qianceng Feixue' × 'Sarah's Favorite'. (c) Embryos 15 d after pollination in H. salicifolia × 'Sarah's Favorite'. (d) Embryos 15 d after pollination in H. myrtifolia × L. fauriei.

    • Figure 7. 

      Immature embryo rescuing of H. salicifolia × 'Sarah's Favorite'. (a) Seedlings 7 d after sowing. (b) Transferred seedlings 20 d after germination. (c) Rooted hybrid seedlings. (d) Rooted hybrid seedlings planted in a pot.

    • Figure 8. 

      Profiles obtained using SSR marker (YYJ951). (a) female (H. salicifolia) profile. (b) paternal ('Sarah's Favorite') profile. (c) hybrid profile. The allele sizes of male and female parents, and hybrid were marked.

    • Figure 9. 

      Branches and flowers of hybrid (H. salicifolia × 'Sarah's Favorite') and its parents. From left to right: H. salicifolia, hybrid, and 'Sarah's Favorite'.

    • L. indica 'Dallas Red' × H. myrtifolia H. myrtifolia × L. indica 'Dallas Red'
      L. indica 'Dallas Red' × H. salicifolia H. salicifolia × L. indica 'Dallas Red'
      L. indica 'Sarah's Favorite' ×
      H. myrtifolia      		 H. myrtifolia × L. indica 'Sarah's Favorite'
      L. indica 'Sarah's Favorite' ×
      H. salicifolia      		 H. salicifolia × L. indica 'Sarah's Favorite'
      L. indica 'Catawba' × H. myrtifolia H. myrtifolia × L. indica 'Catawba'
      L. indica 'Catawba' × H. salicifolia H. salicifolia × L. indica 'Catawba'
      L. indica 'Qianceng Feixue' ×
      H. myrtifolia      		 H. myrtifolia × L. indica 'Qianceng Feixue'
      L. indica 'Qianceng Feixue' ×
      H. salicifolia      		 H. salicifolia × L. indica 'Qianceng Feixue'
      L. fauriei × H. myrtifolia H. myrtifolia × L. fauriei
      L. fauriei × H. salicifolia H. salicifolia × L. fauriei
      L. indica 'Near East' × H. myrtifolia H. myrtifolia × L. indica 'Near East'
      L. indica 'Pocomoke' × H. myrtifolia H. myrtifolia × L. indica 'Pocomoke'
      L. indica 'Centennial Spirit' ×
      H. myrtifolia      		 H. myrtifolia × L. indica 'Centennial Spirit'
      L. indica 'Qianceng Feixue' ×
      'Sarah's Favorite'*      		 H. myrtifolia × H. myrtifolia*
      H. salicifolia × H. salicifolia *

      Table 1. 

      Pollination combinations of Lagerstroemia and Heimia.

    • Medium ID Medium Hormone combination (mg·L−1)
      6-BA NAA GA3
      CK MS 0 0 0
      1 MS 0.5 0 1
      2 1/2 MS 0.5 0.5 1
      3 MS 0.5 0 0.5
      4 MS 0.5 0.5 1
      5 MS 0.5 0.5 1.5
      6 MS 0.5 0 0
      7 MS 0.5 0.5 0

      Table 2. 

      Establishment media used in embryo rescuing.

    • Species and cultivars Germination percentage
      L. indica 'Dallas Red' 85%
      L. indica 'Sarah's Favorite' 92%
      L. indica 'Qianceng Feixue' 85%
      L. fauriei 55%
      L. indica 'Catawba' 87%
      L. indica 'Centennial Spirit' 78%
      L. indica 'Near East' 75%
      L. indica 'Pocomoke' 80%
      H. myrtifolia 55%
      H. salicifolia 65%

      Table 3. 

      Pollen germination rates of eight Lagerstroemia and two Heimia species and cultivars.

    • Female parents (♀) Male parents (♂) No. of pollinated flowers Fruiting
      rate (%)
      L. indica 'Dallas Red' H. myrtifolia 282 0.7
      H. salicifolia 275 0.0
      L. indica 'Sarah's Favorite' H. myrtifolia 545 0.0
      H. salicifolia 330 1.1
      L. indica 'Catawba' H. myrtifolia 224 0.0
      H. salicifolia 268 0.0
      L. indica 'Qiancengfeixue' H. myrtifolia 850 0.0
      H. salicifolia 509 0.0
      L. fauriei H. myrtifolia 200 0.0
      H. salicifolia 350 0.0
      L. indica 'Centennial Spirit' H. myrtifolia 126 0.0
      L. indica 'Near East' 199 0.0
      L. indica 'Pocomoke' 215 0.0
      H. salicifolia L. indica 'Dallas Red' 284 5.4
      L. indica 'Sarah's Favorite' 361 4.1
      L. indica 'Catawba' 98 0.0
      L. indica 'Qiancengfeixue' 127 0.0
      L. fauriei 144 0.0
      H. myrtifolia L. indica 'Dallas Red' 292 0.0
      L. indica 'Sarah's Favorite' 1,650 6.0
      L. indica 'Catawba' 326 0.0
      L. indica 'Qiancengfeixue' 63 0.0
      L. indica 'Centennial Spirit' 306 0.0
      L. indica 'Near East' 242 0.0
      L. indica 'Pocomoke' 308 0.0
      L. fauriei 1,489 3.7
      *L. indica 'Qiancengfeixue' L. indica 'Sarah's Favorite' 193 79.8
      *H. myrtifolia H. myrtifolia 85 74.1
      *H. salicifolia H. salicifolia 75 81.3
      * indicates the control group.

      Table 4. 

      Fruiting rates of pollination combinations between Lagerstroemia and Heimia after spraying 20 mg·L−1 2,4-D.

    • Female
      parents
      (♀)      		 Male
      parents
      (♂)      		 Hormone Concentration (mg·L−1) No. of pollinated flowers Fruiting rate (%)
      L. fauriei H. salicifolia GA3 100 126 11.9
      200 193 16.1
      2,4-D 20 350 0
      50 290 0
      L. indica
      'Sarah's
      Favorite'      		 H. salicifolia GA3 100 230 3.5
      200 222 6.3
      2,4-D 20 330 1.1
      50 173 1.2
      L. indica
      'Qianceng Feixue'      		 H.myrtifolia GA3 100 93 8.6
      200 83 14.5
      2,4-D 20 850 0
      50 163 0
      H. salicifolia L. indica
      'Dallas Red'      		 GA3 100 107 0.9
      200 170 1.2
      2,4-D 20 284 5.4
      50 43 7
      L. indica
      'Sarah's
      Favorite'      		 GA3 100 119 0
      200 27 0
      2,4-D 20 361 4.1
      50 90 8.9
      L. indica
      'Qianceng Feixue'      		 GA3 100 52 0
      200 53 0
      2,4-D 20 127 0
      50 43 0
      L. fauriei GA3 100 79 0
      200 71 0
      2,4-D 20 144 0
      50 40 0

      Table 5. 

      Fruiting rates of pollination combinations between Lagerstroemia and Heimia following treatments with varying concentrations of 2,4-D and GA3.

    • Days after pollination 10 d 15 d 20 d 25 d 30 d
      No. of medium ck 1 2 3 4 5 6 7 ck 1 2 3 4 5 6 7 ck 1 2 3 4 5 6 7 ck 1 2 3 4 5 6 7 ck 1 2 3 4 5 6 7
      Hybrid combinations L.indica 'Sarah's Favorite' 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0
      L.indica 'Dallas Red' × H.salicifolia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0
      H.salicifolia × L.indica 'Dallas Red' 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
      H.salicifolia × L.indica 'Sarah's Favorite' 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 6 3 1 1 0 0 0 0 0 0 0 0 0 0 0
      H.myrtifolia × L.fauriei 0 0 0 0 0 0 0 0 0 0 0 0 5 0 2 0 0 0 0 0 0 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
      H.myrtifolia × L.indica 'Sarah's Favorite' 0 0 0 0 0 0 0 0 0 1 0 0 4 0 6 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
      The hormone combinations corresponding to the medium IDs are presented in Table 2.

      Table 6. 

      Number of seedlings obtained in different media and different times after pollination.

    • Locus Repeat motif Forward primer sequence (5'-3') Reverse primer sequence (5'-3')
      YYJ-951 (GAA)6 5'-GTTCCTGGAGACTTGGGCTC-3' 5'-TCCGAACTTCCCGACGAATG-3'

      Table 7. 

      SSR loci used in hybrid identification.