Greenhouse pollinations were performed to determine whether early-acting inbreeding depression is contributing to low levels of self-fertility in three Vaccinium species: V. myrtilloides Michaux, V. angustifolium Aiton, and V. corymbosum L. All three species showed a significant reduction in self fruit set and in the proportion of fertilized ovules that developed into mature seed in self compared to outcross fruit. Reductions were more severe in V. myrtilloides and V. angustifolium than in V. corymbosum; however, early-acting inbreeding depression appeared to be the primary factor limiting self-fertility in all three species. Evidence for earlyacting inbreeding depression included the presence and higher proportion of aborted ovules in self fruit than in outcross fruit, a correlation between levels of self and outcross seed set, and pollen chase experiments demonstrating that self-pollen does fertilize the ovules. Selffertility in the three species was probably influenced by levels of genetic load, ploidy level and outcrossing rates.

No abstract

No abstract

No abstract

Populations of P. infestans are dynamic, with mutation, migration, sexual reproduction, and host having contributed to the evolution of new clonal lineages or genotypes with different epidemiological, genotypic, and phenotypic characteristics (Goodwin, 1997; Hu et al., 2012). Globalization has increased the trade in agricultural commodities such as potato between countries. Potato tubers intended for processing or for use as seed are imported or exported from one country to another based on supply and demand. P. infestans remains dormant (latent) in seed tubers at low temperatures (4°C). As such, symptomless seed tubers are easily overlooked in intercontinental shipments (Johnson and Cummings, 2009). The introduction of new genotypes in seed tubers has resulted in changes in local population compositions of