Environment-dependent microevolution in a Mediterranean pine (Pinus pinaster Aiton).

Background: A central question for understanding the evolutionary responses of plant species to rapidly changing environments is the assessment of their potential for short-term (in one or a few generations) genetic change. In our study, we consider the case of Pinus pinaster Aiton (maritime pine), a widespread Mediterranean tree, and (i) test, under different experimental conditions (growth chamber and semi-natural), whether higher recruitment in the wild from the most successful mothers is due to better performance of their offspring; and (ii) evaluate genetic change in quantitative traits across generations at two different life stages (mature trees and seedlings) that are known to be under strong selection pressure in forest trees.

Results: Genetic control was high for most traits (h2 = 0.

PSA: software for parental structure analysis of seed or seedling patches.

Parental structure analysis (PSA) is a computer program to analyse separate contributions of paternal and maternal parents to postdispersal plant offspring. The program provides joint estimates of maternal, paternal and cross-parental correlations within and among a set of predefined groups of seeds or seedlings, as well as derivative estimates of effective parental numbers. PSA utilizes data sets that distinguish between maternal and paternal contributions to the genotype of each offspring in the sample, but does not require parental samples per se.