Maternal effects and genotype interact to affect germination responses to light quality

LINDSAY D LEVERETT; GABRIELA A AUGE; AMAN BALI; KATHLEEN DONOHUE

Córdoba

Congreso; 16th International Congress on Photbiology; 2014

International Unon of Photobiology

Germination sensitivity to environmental factors after dispersal depends on the genotype and the conditions experienced during seed maturation (maternal environment) [1]. Changes in temperature and resources in the maternal environment have been shown to affect the dormancy status and germination of seeds [2]. We tested whether changes in the quality of the maternal light environment affect seed germination responses to combinations of temperature and light conditions. Two genotypes of Arabidopsis thaliana known to differ in germination [3] were grown in long days (16h light) at 22°C until bolting, then transferred to short days (8h light) at 15°C. Seeds were matured under two light environments: 1) white light (WL, Red (R):Far red (FR) ratio ~1.4), and 2) a simulated vegetative canopy (R:FR ~0.3). Freshly harvested seeds were incubated under WL, darkness and a simulated canopy at 10 and 22°C. Our results show that maturation under the canopy reduced dormancy overall. While seed maturation in a low R:FR promoted germination across all incubation treatments at 10°C, at 22°C this effect was more pronounced when seeds were incubated under WL, indicating that the effect of maternal conditions on germination response to light is dependent on temperature. Furthermore, genotypic differences in germination were reduced across all the incubation conditions when seeds were matured under a canopy environment. Overall, our findings suggest that in habitats with heterogeneity in light quality, the maternal and seed environments could interact with genetic differences to affect the germination response and potentially seedling success.[1] W.E. Finch-Savage, G. Leubner-Metzger. New Phytol. 2006, 171, 501.[2] M. Fenner, K. Thompson. The Ecology of Seeds. 2005, Cambridge: Cambridge University Press.[3] G.C.K. Chiang et al. PNAS 2009, 106, 11661.