Pollen limitation and reproductive incompatibility system in a critically endangered tree, Polylepis incarum (Bitter) M. Kessler & Schmidt-Leb (Rosaceae)

Figures & data

Figure 1. (a) Viable seeds with endosperm present and viable embryo), (b) Seed with endosperm present and aborted embryo, (c) Seed without endosperm and nonviable embryo, and (d) Seed without endosperm and aborted embryo

Figure 2. Viable (VP) and non-viable (NVP) pollen grains of Polylepis incarum stained with tetrazolium, and the presence of bubbles (B)

Figure 3. Percentage of fruit set following cross-hand-pollination (CP), open pollination (OP) self-hand-pollination (SP) and spontaneous self-pollination (SPO) of Polylepis incarum. Different letters indicate significant differences (P < 0.01)

Table 1. Percentage of viable seeds (Mean ± SD) produced by cross-hand-pollinated, open-pollinated, self-pollinated, and spontaneous self-pollinated flowers produced by Polylepis incarum in western Bolivia

	Cross-pollination	Open-pollination	Self-pollination	Spontaneous self-pollination
No of trees	15	15	15	15
No of inflorescences/ flowers	30/186	30/218	30/181	30/181
No of fruits/ seeds	184/184	181/181	173/173	173/173
Produced seeds (%)	97.5 ± 9.4	84.4 ± 1.8	96.2 ± 8.4	84.4 ± 3.3
Viable seeds (%)	56.9 ± 13.4	55.4 ± 12.8	33. ± 17.97	41.3 ± 19.47

Figure 4. Percentage of viable and non-viable seeds following cross-hand-pollination (CP), open pollination (OP), self-hand-pollination (SP) and spontaneous self-pollination (SSP) of Polylepis incarum. Asterisks indicate significant differences among treatments at P < 0.01

Figure 5. Percentage of pollen germination, pollen tubes in the style, and pollen tubes reaching the ovary following cross-hand-pollination (CP), open pollination (OP), and self-hand-pollination (SP) of Polyelpis incarum.

Figure 6. (a) Gynoecium of Polylepis incarum stained with aniline blue, (b) Pollen grains (PG) and pollen tubes (PT), (c) Germinated pollen grains (GPG) and (d) Pollen tubes (PT) on style reaching the ovary