Parental environment aftereffects on germination, growth, and adaptive traits in selected white spruce families

Abstract

Seed orchards for the production of conifer seed in British Columbia are usually located in areas favorable (warm and dry) for flowering and seed development, often considerably south of the source location of the parent trees. Differences in environmental conditions between seed orchard location and location of origin can affect progeny performance. It is suspected that this is caused by environmental factors that affect reproductive processes of parent trees and lead to altered physiological traits (aftereffects). This study examined if aftereffects are present in white spruce (Picea glauca (Moench) Voss). Control pollinations were made at two locations, Red Rock, near Prince George (53°N) in central British Columbia, and Kalamalka, near Vernon (50°N) in southern British Columbia, on five female trees using a four-male polymix. Identical genotypes through grafting were present at the two locations. Pollen maturing at each site was only used in the polymix at that particular location. Progeny were raised and germination traits, number of needle primordia, greenhouse and field heights, and frost hardiness were evaluated in a common environment. The location of seed development significantly affected all traits evaluated. Height growth aftereffects in the second field season were much less than those observed in the first field season. These results suggest that aftereffects are detectable in white spruce progeny performance in British Columbia.Résumé : En Colombie-Britannique, les vergers destinés à la production de graines de conifères sont généralement établis dans des endroits favorables (chauds et secs), souvent considérablement plus au sud que l'origine géographique des sources parentales de graines, afin de favoriser la floraison et le développement des graines. Les auteurs rapportent que les différences environnementales entre le lieu d'établissement des vergers à graines et l'origine géographique des sources parentales de graines peuvent affecter la performance des descendances. Ceci serait causé par des facteurs environnementaux affectant les processus de reproduction des arbres parents et menant à l'altération des caractères physiologiques (effets reportés). Les auteurs ont voulu vérifier si ces effets reportés étaient présents chez l'épinette blanche (Picea glauca (Moench) Voss). Pour ce faire, des croisements contrôlés ont été réalisés dans deux endroits, à Red Rock près de Prince-George (53°N) en Colombie-Britannique centrale, et à Kalamalka, près de Vernon (56°N) en Colombie-Britannique méridionale. Les croisements ont été réalisés sur cinq arbres femelles à l'aide d'un mélange de pollen provenant de quatre arbres mâles. Les génotypes parentaux découlaient de greffes et étaient identiques d'un site à l'autre. Le mélange de pollen utilisé pour chacun des sites provenait de pollen ayant maturé sur le même site. Après avoir mis les descendances en production au sein d'un test comparatif, différents caractères furent évalués : des caractères de germination, le nombre de primordia foliaires, la hauteur e...

Mediation of seed provisioning in the transmission of environmental maternal effects in Maritime pine (Pinus pinaster Aiton)

“…Some authors only found effects of the maternal environment (for example, Galloway et al, 2009), whereas others have found the opposite (for example, Halpern, 2005). Most frequently, however, both factors have been found to significantly affect mean SM (for example, Stoehr et al, 1998;Elwell et al, 2011). Our results agree with these studies, and clearly show a strong genetic component in SM as well as a large influence of the maternal environment (Table 2, Figure 1).…”

“…Further research analysing parent-offspring regression and/or family trials should determine the amount of additive variation within the observed genetic variation in SM in this pine species. Because SM has a relevant role in many important life history processes, many studies have focussed on determining the sources of SM variation in different plant species, but the effects of the maternal environment and the maternal genotype have not always been adequately separated (Blodner et al, 2007;Guo et al, 2010), and when they have been separated (Halpern, 2005;Galloway et al, 2009;House et al, 2010), they have usually referred to annual plants (but see Stoehr et al, 1998). Results are very variable.…”

Epigenetic memory effects in forest trees: a victory of “Michurinian biology”?

“…It appeared that the seeds produced in southern seed orchards 'remember' in some way the climate at the site of production, despite containing genes inherited from parents originating from the North (hence the designation 'memory' or 'carryover' effects). Similar observations were made on North-American conifers (Greenwood and Hutchison 1996;Stoehr et al 1998;Webber et al 2005).…”

Genetic control of Eucalyptus globulus seed germination

“…There are few such studies in long-lived forest trees, but an example include the demonstration of "seed after-effects" whereby the environment experienced by parents and developing seeds in a tree seed orchard may affect the expression of phenotypic variation in the subsequent deployment population (Andersson 1994;Stoehr et al 1998). Few studies allow the separation of maternal embryonic nuclear and maternal effects (Rasanen and Kruuk 2007;Monty et al 2009;Bischoff and Muller-Scharer 2010), particularly in the case of forest trees (Besnard et al 2008).…”