Quantitative analysis of pollination diallels of two Australian species of Pandorea (Bignoniaceae)

Summary The genus Pandorea, family Bignoniaceae, occurs naturally in Australia. Pandorea pandorana and P. jasminoides were used in intraspecific diallel crosses in order to test for the presence of self-incompatibility and the effect of genotype. Both species were found to be highly self-incompatible. Only 2 out of 353 (0.6%) selfpollinations compared to 337 out of 485 (69.5%) of outcross-pollinations of P. pandorana set fruit. Similarly, for P. jasminoides, 4 out of 235 (1.7%) self-pollinations and 175 out of 296 (59.1%) of outcross pollinations set fruit. Both reciprocal and genotype effects were found in P. pandorana. Fruit-set differences occurred between two different genotypes of P. jasminoides, but reciprocal effects were not found. Data were analysed using generalized linear models with a logit-link function assuming a binomial error distribution. The relative merits of the various models are discussed.