La Trobe

File(s) not publicly available

Diversity of S-alleles and mate availability in 3 populations of self-incompatible wild pear (Pyrus pyraster)

journal contribution
posted on 2021-02-10, 23:15 authored by Susan HoebeeSusan Hoebee, S Angelone, D Csencsics, K Määttänen, R Holderegger
Small populations of self-incompatible plants may be expected to be threatened by the limitation of compatible mating partners (i.e., S-Allee effect). However, few empirical studies have explicitly tested the hypothesis of mate limitation in small populations of self-incompatible plants. To do so, we studied wild pear (Pyrus pyraster), which possesses a gametophytic self-incompatibility system. We determined the S-genotypes in complete samplings of all adult trees from 3 populations using a PCR-RFLP approach. We identified a total of 26 different S-alleles, homologous to S-alleles of other woody Rosaceae. The functionality of S-alleles and their Mendelian inheritance were verified in artificial pollination experiments and investigations of pollen tube growth. The smallest population (N = 8) harbored 9 different S-alleles and showed a mate availability of 92.9%, whereas the 2 larger populations harbored 18 and 25 S-alleles and exhibited mate availabilities of 98.4% and 99.2%, respectively. Therefore, we conclude that even small populations of gametophytic self-incompatible plants may exhibit high diversity at the S-locus and are not immediately threatened owing to reduced mate availability. © The American Genetic Association. 2011. All rights reserved.


Swiss Agency for the Environment BAFU (project "Protection and Use of Forest Genetic Resources'').


Publication Date



Journal of Heredity






(p. 260-267)





Rights Statement

The Author reserves all moral rights over the deposited text and must be credited if any re-use occurs. Documents deposited in OPAL are the Open Access versions of outputs published elsewhere. Changes resulting from the publishing process may therefore not be reflected in this document. The final published version may be obtained via the publisher’s DOI. Please note that additional copyright and access restrictions may apply to the published version.