Seed germination and rising atmospheric CO₂ concentration: a meta‐analysis of parental and direct effects

Abstract

SummaryPlant regeneration from seed is largely governed by germinability and speed of germination. These fitness components have received considerably less attention in CO 2 research relative to studies of vegetative or reproductive output responses. Moreover, the limited literature has not been rigorously examined for generalizable patterns of responses and/or potential mechanisms. We used a meta-analytic approach to summarize literature results of seed germination characteristics in response to parental CO 2 enrichment (eCO 2 ). The direct effects of eCO 2 on germination components were also analyzed. The data set came from 29 original research papers encompassing 64 species and 116 observations. Across all studies, parental eCO 2 increased subsequent germination by 9%, but the responses varied among species by as much as 300%. The response was significantly higher in trees than in other life forms. With the exception of crops, parental eCO 2 also increased germination rate in most life forms and functional groups. Despite a considerable interspecific variability, we found a positive correlation between germination success and seed mass responses to parental eCO 2 . Therefore, the observed diversity of regeneration success responses to parental eCO 2 is partly controlled by the direction and magnitude of changes in seed mass.

Seed traits and germination of native grasses and invasive forbs are largely insensitive to parental temperature and CO2concentration

“…Impacts of CO 2 enrichment, warming, and the combination of these two on seed germination were consistent across a wide range of temperature regimes (Table 4). Seed germination response to warming and/or elevated CO 2 concentrations is species specific, agreeing with previous studies (Huxman et al , 1998; Williams et al , 2007; Gao et al , 2012; Marty and BassiriRad, 2014). Future climate condition (CT) favoured seed germination of C 4 grass B. gracilis but not the three C 3 species in this study.…”

Parental Selection of Hybrid Breeding Based On Maternal and Paternal Inheritance of Traits in Rapeseed (Brassica napus L.)

“…The maternal effect of various seed traits including seed size was shown in many other crops to be correlated with parental environmental effects (e.g. availability of light, temperature, water, and nutrients) and cytoplasmic effects [39] – [40] . Based on the contribution ratio of GCA variance and correlation between heterosis levels and GCA of parents, paternal parent contributed more than maternal parent for SY, which provided valuable information for SY improvement in hybrid breeding of rapeseed.…”

Raised atmospheric CO2 levels affect soil seed bank composition of temperate grasslands

“…In general, higher biomass production under CO 2 enrichment may result in more seeds because more resources can be allocated to reproduction (Jablonski et al., ). This effect is enhanced by changes in resource acquisition due to elevated CO 2 , which also supports higher seed production (Marty & BassiriRad, ).…”

“…Still, a closer look at the effects of the CO 2 treatment revealed several significant effects, such as higher seed densities under eCO 2 . Different studies have shown that eCO 2 affects seed production and seed germination in grassland (Bloor et al., ; Edwards et al., ; Jablonski et al., ; Marty & BassiriRad, ).…”