Reproductive system in the Iberian endangered endemic Antirrhinum valentinum F.Q. (Antirrhineae, Scrophulariaceae): consequences for species conservation

Mateu-Andrés, I.; Segarra-Moragues, J.G.. Reproductive system in the Iberian endangered endemic Antirrhinum valentinum F.Q. (Antirrhineae, Scrophulariaceae): consequences for species conservation. International Journal of Plant Sciences. 2004, Vol. 165(5), p. 773-2004.

A comparison of four pollination treatments revealed that Antirrhinum valentinum is self-incompatible but
shows low levels of spontaneous self-fertility. Seed sets, after hand cross-pollination and spontaneous selffertilization,
were significantly fewer than in control flowers, but fruit and seed mass were not significantly
different. Pollen tube growth was slower after selfing than crossing, being arrested in the stigmata or in the
upper part of the style. Multilocus outcrossing rates (tm) were high and tm  ts (ts ¼ single-locus outcrossing
rate) small, indicating low levels of biparental inbreeding. Despite that, the estimated neighborhood sizes were
from six to seven individuals, which can be considered low because the number of seeds per fruit ranges
between 150 and 200. This apparent incongruence is explained by the small size of populations together with
the multiallelic gametophytic control of self-incompatibility, making possible crossing between half-sibs. On
the basis of these data, recommendations to develop reinforcement or reintroduction programs as well as for in
vitro propagation of plants are given.