Heritability of seed weight in Maritime pine, a relevant trait in the transmission of environmental maternal effects

Abstract

Quantitative seed provisioning is an important life-history trait with strong effects on offspring phenotype and fitness. As for any other trait, heritability estimates are vital for understanding its evolutionary dynamics. However, being a trait in between two generations, estimating additive genetic variation of seed provisioning requires complex quantitative genetic approaches for distinguishing between true genetic and environmental maternal effects. Here, using Maritime pine as a long-lived plant model, we quantified additive genetic variation of cone and seed weight (SW) mean and SW within-individual variation. We used a powerful approach combining both half-sib analysis and parent-offspring regression using several common garden tests established in contrasting environments to separate G, E and G Â E effects. Both cone weight and SW mean showed significant genetic variation but were also influenced by the maternal environment. Most of the large variation in SW mean was attributable to additive genetic effects (h 2 ¼ 0.55-0.74). SW showed no apparent G Â E interaction, particularly when accounting for cone weight covariation, suggesting that the maternal genotypes actively control the SW mean irrespective of the amount of resources allocated to cones. Within-individual variation in SW was low (12%) relative to between-individual variation (88%), and showed no genetic variation but was largely affected by the maternal environment, with greater variation in the less favourable sites for pine growth. In summary, results were very consistent between the parental and the offspring common garden tests, and clearly indicated heritable genetic variation for SW mean but not for within-individual variation in SW.

Genetic and environmental effects on seed weight in subspecies of big sagebrush: applications for restoration

“…Seed lots labeled with letters indicate high (A, C) and low (B, D) weight seed that was germinated for confirming cytotype proportions. 2012) and have high heritability (Zas and Sampedro 2014). As described elsewhere (Zas and Sampedro 2014), partitioning maternal genetic versus maternal environment effects requires methodology beyond the scope of this study.…”

“…2012) and have high heritability (Zas and Sampedro 2014). As described elsewhere (Zas and Sampedro 2014), partitioning maternal genetic versus maternal environment effects requires methodology beyond the scope of this study. However, the variation in seed weight exhibited in original maternal environment and seed from daughters in common gardens of contrasting environments showed seed weight is consistent across environments compared to other traits.…”

Conflicting selection onCneorum tricoccon(Rutaceae) seed size caused by native and alien seed dispersers

“…Despite the apparently low effect at the germination stage, the odds for larger seeds to be recruited in the population are still higher than for smaller seeds that are less frequently dispersed. Hence, considering that seed size is an heritable trait (e.g., Wheelwright 1993;Gómez 2008;Galetti et al 2013;Zas and Sampedro 2015), we might expect long-lasting evolutionary effects of the selection of large seeds by the alien pine martens at the plant population level. Even if pine martens had been introduced only 500 years ago (Valenzuela and Alcover 2013), the time that these animals have coexisted with C. tricoccon in Mallorca island might be enough for them to promote phenotypic evolution on seed size (see also Galetti et al 2013).…”

Provenance and seed mass determine seed tolerance to high temperatures associated to forest fires in Pinus pinaster

“…However, there is a general lack of information on the species linking the serotiny level of the maternal population from which seeds are harvested and the resultant post-fire tree recruitment (Vega et al 2008). Moreover, extremely high variability in seed mass exists within and among P. pinaster provenances (Escudero et al 2000;Zas and Sampedro 2015;Zas et al 2013), similarly to other pine species (e.g. Court-Picon et al 2004;Ganatsas et al 2008;Liu et al 2013;Parker et al 2006).…”