Limits...
Evidence for asymmetrical hybridization despite pre- and post-pollination reproductive barriers between two Silene species

View Article: PubMed Central - PubMed

ABSTRACT

Co-flowering species may undergo interspecific hybridization if they are closely related and share pollinators. However, a series of reproductive barriers between species can prevent interspecific gene flow, making natural hybridization a transient, rare event. Both morphological and molecular data indicated putative natural hybrids between two Silene species from southwest China, with pollen from S. yunnanensis fertilizing ovules of S. asclepiadae. Zhang et al. found that pollen production and viability were significantly lower in putative hybrids than the parental species. The low fecundity of the hybrids and other reproductive barriers between the two species could contribute to species fidelity.

No MeSH data available.


Fecundity measures for S. asclepiadea, putative hybrids and S. yunnanensis in (a) seed set, (b) number of seeds and (c) seed mass under open pollination. Values indicate means ± SE. Bars with different letters differ significantly (P < 0.05).
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4940505&req=5

plw032-F8: Fecundity measures for S. asclepiadea, putative hybrids and S. yunnanensis in (a) seed set, (b) number of seeds and (c) seed mass under open pollination. Values indicate means ± SE. Bars with different letters differ significantly (P < 0.05).

Mentions: Fruit set of open-pollinated flowers averaged 68.56 % (± 2.35 %) in S. asclepiadea and 67.74 % (± 2.97 %) in S. yunnanensis, and did not differ statistically between them (F1, 58 = 0.047, P = 0.829). When compared with S. asclepiadea (19.95 ± 3.69 %), predation of developing fruits was significantly higher (F1, 58 = 49.561, P < 0.01) in S. yunnanensis (63.96 ± 5.04 %). For putative hybrids, the fruit set and percent of fruits exhibiting herbivory were 52.21 % (± 6.58 %) and 17.35 % (± 8.93 %), respectively. We did not compare the differences between putative hybrids and parental species for fruit set or percent of fruit damaged by herbivores because small sample sizes for the hybrids limited statistical power. Seed set between S. asclepiadea and S. yunnanensis was not significantly different, but was significantly higher than in the putative hybrids (F2, 87 = 47.63, P < 0.01) (Fig. 8a). Similarly, the putative hybrids produced significantly fewer seeds per fruit than did S. asclepiadea and S. yunnanensis (F2, 87 = 48.31, P < 0.01) (Fig. 8b). Average seed mass significantly differed (F2, 87 = 95.92, P <  0.01), with the mass highest in S. asclepiadea, intermediate in S. yunnanensis and lowest in the putative hybrids (Fig. 8c).Figure 8.


Evidence for asymmetrical hybridization despite pre- and post-pollination reproductive barriers between two Silene species
Fecundity measures for S. asclepiadea, putative hybrids and S. yunnanensis in (a) seed set, (b) number of seeds and (c) seed mass under open pollination. Values indicate means ± SE. Bars with different letters differ significantly (P < 0.05).
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4940505&req=5

plw032-F8: Fecundity measures for S. asclepiadea, putative hybrids and S. yunnanensis in (a) seed set, (b) number of seeds and (c) seed mass under open pollination. Values indicate means ± SE. Bars with different letters differ significantly (P < 0.05).
Mentions: Fruit set of open-pollinated flowers averaged 68.56 % (± 2.35 %) in S. asclepiadea and 67.74 % (± 2.97 %) in S. yunnanensis, and did not differ statistically between them (F1, 58 = 0.047, P = 0.829). When compared with S. asclepiadea (19.95 ± 3.69 %), predation of developing fruits was significantly higher (F1, 58 = 49.561, P < 0.01) in S. yunnanensis (63.96 ± 5.04 %). For putative hybrids, the fruit set and percent of fruits exhibiting herbivory were 52.21 % (± 6.58 %) and 17.35 % (± 8.93 %), respectively. We did not compare the differences between putative hybrids and parental species for fruit set or percent of fruit damaged by herbivores because small sample sizes for the hybrids limited statistical power. Seed set between S. asclepiadea and S. yunnanensis was not significantly different, but was significantly higher than in the putative hybrids (F2, 87 = 47.63, P < 0.01) (Fig. 8a). Similarly, the putative hybrids produced significantly fewer seeds per fruit than did S. asclepiadea and S. yunnanensis (F2, 87 = 48.31, P < 0.01) (Fig. 8b). Average seed mass significantly differed (F2, 87 = 95.92, P <  0.01), with the mass highest in S. asclepiadea, intermediate in S. yunnanensis and lowest in the putative hybrids (Fig. 8c).Figure 8.

View Article: PubMed Central - PubMed

ABSTRACT

Co-flowering species may undergo interspecific hybridization if they are closely related and share pollinators. However, a series of reproductive barriers between species can prevent interspecific gene flow, making natural hybridization a transient, rare event. Both morphological and molecular data indicated putative natural hybrids between two Silene species from southwest China, with pollen from S. yunnanensis fertilizing ovules of S. asclepiadae. Zhang et al. found that pollen production and viability were significantly lower in putative hybrids than the parental species. The low fecundity of the hybrids and other reproductive barriers between the two species could contribute to species fidelity.

No MeSH data available.