REPRODUCTIVE BEHAVIOUR AND INCOMPATIBILITY IN ‘STELLA’ SWEET CHERRY

Most sweet cherries express gametophytic self-incompatibility controlled by alleles of the S gene. ‘Stella’ is self-fertile and is heterozygous for the mutant S₄‘ allele.
Thus, ‘Stella’ is semi-compatible when selfed.
Heterozygotes and S₄‘S₄‘ homozygotes were expected to segregate in the ratio 2:1. Glutamate Oxaloacetate Transaminase (GOT) isoenzymes have previously been shown to be linked to the S gene in cherry. ‘Stella’ is heterozygous, bc, for GOT and, after selfing, resultant progeny would be expected to segregate for heterozygous to homozygous genotypes in a ratio of 2:1, with the homozygote being bb or cc, depending on which allele was linked to the S₄‘ allele.
Isoenzyme analysis of seedlings from the selfing of ‘Stella’ revealed a deficiency of GOT homozygotes; all the progeny had the heterozygous genotype bc. This indicated that S₄‘S₄‘ homozygotes had not been formed, suggesting S₄‘ pollen was still being recognised.
Controlled pollinations combined with fluorescence microscopy provided evidence that the incompatibility genotype of ‘Stella’ is S₄S₄‘ and that ovarian rather than stylar recognition/inhibition of S₄‘ pollen tubes occurred.

Eucarpia Symposium on Fruit Breeding and Genetics

A.R. Granger

Prunus avium, isoenzymes, pollen tubes

https://doi.org/10.17660/ActaHortic.1998.484.41