Biases in quantitative genetic analyses using open-pollinated progeny tests from natural tree populations

AbstractIn plant quantitative genetic studies conducted ex situ, the large number of seeds produced per individual has promoted the use of open-pollinated progeny tests. In subsequent analyses, seeds collected on the same mother-plant are assumed to be half-sibs. The consequences of the departure from half-sib assumption in progeny tests have been investigated since the 1960s using simulation approaches and, more recently, using molecular-based experimental approaches. This review aims to synthesize the results and conclusions of these simulation and empirical studies. We focus on tree species, where controlled crosses are difficult to carry out experimentally and departures from half-sib assumptions occur frequently in natural populations. First, the average level of relatedness expected within maternal progeny for many tree populations is higher than that of half-sibs. This is the consequence of non-random mating resulting from the small number of effective pollen donors per female, unequal male reprodu...