Fig 1.
The flowers of jasmine cultivars exhibit differing petal phenotypes.
(a) The single-petal (SP, left), double-petal (DP, middle) and multi-petal (MP, right) flowers. (b) A pistil of DP flower showing the sampled position (indicated by arrow head) of the style for ultrastructural observation.
Fig 2.
Pollen in vitro culture of three jasmine petal-types at different developmental stages.
(a) Germination of the double-petal (DP) jasmine pollen grains in Stage 1 (i.e., one day before flowers partially opened). (b) Germination of the single-petal (SP) jasmine pollen grains in Stage 4 (i.e., one day post flowers fully opened). (c) Germination of the DP jasmine pollen grains in Stage 4. (d) Germination of the multi-petal (MP) jasmine pollen grains in Stage 4.
Table 1.
Pollen viability of three jasmine petal-types during flowering.
Fig 3.
The fluorescent observation of pollen grains adhered on stigmas of jasmine three petal-types at different developmental stages.
(a) The single petal (SP) jasmine pistil in Stage 2 (i.e., partially opened flowers). The pollen grains were indicated by arrow heads. (b) The double petal (DP) jasmine pistil in Stage 2. The pollen grains were indicated by arrow heads. (c) The multi-petal (MP) jasmine pistil in Stage 1 (i.e., one day before flower partially opened). The pollen grains were indicated by arrow heads. (d) The SP jasmine pistil in Stage 4 (i.e., one day post flower fully opened). (e) The DP jasmine pistil of at Stage 4. The pollen grains were indicated by arrow heads. (f) The MP jasmine pistil in Stage 4. The pollen grains were indicated by arrow heads. Abbreviation: St, stigma
Table 2.
Germination ratio of pollen grains on the stigmas at different flowering stages after artificial pollination of three jasmine petal-types.
Fig 4.
The SEM observation of pollen germination and pollen tube growth in different cross combinations among single-petal (SP), double-petal (DP) and multi-petal (MP) jasmine plants.
(a) At 1 h after pollination (HAP), in SP × DP (pollen receptor × pollen donor), the pollen tube had just emerged from the germinal aperture. (b) At 2 HAP, in SP × DP, the pollen tube had penetrated into the stigma. (c) At 2 HAP, in DP × MP, the pollen tube had penetrated into the stigma. (d) At 8 HAP, in SP × DP, the number of geminated pollen grains (arrow heads) reached the peak. (e) At 8 HAP, in DP × SP, the number of geminated pollen grains (arrow heads) reached the peak. (f) In MP × DP, the number of geminated pollen grains (arrow heads) reached the peak at 12 HAP. (g) In SP × DP, a circulated and twisted pollen tube on the stigmatic surface at 12 HAP. (h) In MP × SP, a collapsed pollen tube on the stigma at 12 HAP. (i) In SP × MP, a pollen tube enlarged abnormally just after emerging from the aperture at 12 HAP. Abbreviations: PG, pollen grain; PT, pollen tube; St, stigma
Fig 5.
The fluorescent microscope observation of pollen germination and pollen tube growth in different cross combinations among single-petal (SP), double-petal (DP) and multi-petal (MP) jasmine plants.
(a) The percentage of pollen grains on stigmas at different hours after pollination (HAP). ** and * represent significant differences at the level of P < 0.01 and 0.05, respectively. (b) A style of SP jasmine crossed with DP jasmine exhibiting several pollen tubes (arrowheads) in the upper position of the style at 24 HAP. (c) A style of DP jasmine crossed with MP jasmine exhibiting no pollen tube in the style at 24 HAP. Abbreviations: PG, pollen grain; Sti, stigma; Sty, style.
Fig 6.
Development of the pollinated embryo sacs in reciprocal crosses among single-petal (SP), double-petal (DP) and multi-petal (MP) jasmine plants and self-pollinated plants.
(a) Unfertilized embryo sac (arrow head) of SP × DP at 3 d after pollination (DAP). (b) Unfertilized embryo sac (arrow head) of SP × MP degenerated at 5 DAP. (c) Unfertilized embryo sac (arrow head) of DP × SP at 3 DAP. (d) Unfertilized embryo sac (arrow head) of DP × MP degenerated at 5 DAP. (e) Unfertilized embryo sac (arrow head) of MP × SP at 3 DAP. (f) Unfertilized embryo sac (arrow head) of MP × DP degenerated at 4 DAP. (g) A multi-cellular embryo (arrow) of SP × SP at 5 DAP. (h) A globular embryo (arrow) of DP × DP at 10 DAP. (i) A mature fruit (arrow) of DP × DP. Abbreviation: OV: ovule. Scale bars: 100 μm
Fig 7.
Electron micrographs of stigmas and styles of the single-petal (SP) jasmine plants.
(a–c) Stigmas sampled from the partially opened flowers (i.e., Stage 2). (a) Multi-cellular section exhibiting the ultrastructural characteristics. Note the starch granules in the chloroplasts. (b) Enlarged graph of (a) showing the organelles including chloroplasts, starch granules, and mitochondria. (c) A single chloroplast. (d–e) Styles sampled at Stage 2. (d) Multi-cellular section exhibiting the ultrastructural characteristics. (e) Enlarged graph of (d) showing the transfer cell. (f–i) Stigmas sampled from the fully opened flowers (i.e., Stage 3). (f) Multi-cellular section exhibiting the ultrastructural characteristics. Notice fewer starch granules were observed. (g) Enlarged graph of (f) showing several cells and their organelles. (h) Enlargement of (g) showing a single chloroplast. (i) Enlargement of (h) showing the grana and lamellae (arrow heads). (j–k) Styles sampled at Stage 3. (j) Multi-cellular section exhibiting the ultrastructural characteristics. (k) Enlarged graph of (j) showing the transfer cell. (l–m) Stigmas sampled from the flowers at one day post fully opened (i.e., Stage 4). (l) Multi-cellular section exhibiting its ultrastructural characteristics. Notice the cells were of irregular shape and intercellular spaces were larger than normal. (m) A single chloroplast showing fewer grana and lamellae (arrow heads) than normal. (n–o) Styles sampled at Stage 4. (n) Multi-cellular section exhibiting the ultrastructural characteristics. (o) A single chloroplast showing the degenerating grana and lamellae. Notice the plasmolysis (arrow) occurred. Abbreviations: Ch, chloroplast; CW, cell wall; Mi, mitochondria; SG, starch granule
Fig 8.
Electron micrographs of stigmas and styles of the double-petal (DP) jasmine plants.
(a–c) Stigmas sampled from partially opened flowers (i.e., Stage 2). (a) Multi-cellular section exhibiting the ultrastructural characteristics. Several starch granules were observed in each chloroplast. (b) Enlarged graph of (a) showing a single chloroplast with starch granules. (c) Enlargement of the chloroplast showing the grana and lamellae (arrow heads). (d–e) Styles sampled at Stage 2. (d) Multi-cellular section exhibiting the ultrastructural characteristics. Note several starch granules in each chloroplast. (e) The transfer cell. (f–h) Stigmas sampled from fully opened flowers (i.e., Stage 3). (f) Multi-cellular section exhibiting the ultrastructural characteristics. Note starch granules were not observed although chloroplasts still existed. (g) Enlarged graph of (f) showing several chloroplasts. (h) Enlargement of a chloroplast showing the grana and lamellae. (i–j) Styles sampled at Stage 3. (i) Multi-cellular section exhibiting the ultrastructural characteristics. (j) Enlarged graph of (i) showing a chloroplast. Notice the grana and lamellae were empty and fewer than normal. (k–m) Stigmas sampled from flowers at one day post fully opened (i.e., Stage 4). (k) Multi-cellular section exhibiting the ultrastructural characteristics. Notice the shape of cells was irregular. (l) Enlarged graph of (k) showing the cellular organelles. (m) A single chloroplast with flaccid grana and lamellae (arrow heads). (n–o) Styles sampled at Stage 4. (n) Multi-cellular section exhibiting the ultrastructural characteristics. Notice the cells had degenerated, and the organelles were fuzzy and unclear. (o) A degraded chloroplast. Notice the plasmolysis (arrow heads) occurred and sized cavities had formed. Abbreviations: Ch, chloroplast; CW, cell wall; Mi, mitochondria; SG, starch granule
Fig 9.
Electron micrographs of stigmas and styles of the multi-petal (MP) jasmine plants.
(a–b) Stigmas sampled from the flowers at one day before partially opened (i.e., Stage 1). (a) Multi-cellular section exhibiting the ultrastructural characteristics. Note many starch granules were observed. (b) Enlarged graph of (a) showing the chloroplasts and starch granules. (c–e) Styles sampled at Stage 1. (c) Multi-cellular section exhibiting the ultrastructural characteristics. Notice the cells contained dense cytoplasm. (d) Enlargement of the cell showing its organelles. (e) Enlargement of a single chloroplast with starch granules. (f–g) Stigmas sampled from the partially opened flowers (i.e., Stage 2). (f) Multi-cellular section exhibiting the ultrastructural characteristics. Note the chloroplasts were fewer than normal and starch granules were nearly disappeared. (g) Enlarged graph of a single chloroplast with irregular grana and lamellae. (h–j) Styles sampled at Stage 2. (h) Multi-cellular section exhibiting the ultrastructural characteristics. (i) Enlarged graph of (h) showing the cellular containers. (j) Enlarged graph of (h) showing the lamellae (arrow heads). (k–m) Stigmas sampled from the fully opened flowers (i.e., Stage 3). (k) Multi-cellular section exhibiting its ultrastructural characteristics. Notice no starch granules were observed in the cells. (l) Enlarged graph of (k) showing the degenerated cellular organelles. (m) Another cell showing the degraded nucleus and its apoptotic bodies (arrow heads). (n–o) Styles sampled at Stage 3. (n) Multi-cellular section exhibiting its ultrastructural characteristics. Notice the cellular organelles had entirely degenerated. (o) Enlargement of the stylar cell showing its degenerated containers. Abbreviations: Ch, chloroplast; CW, cell wall; Mi, mitochondria; SG, starch granule