Habitat-correlated seed germination and morphology in populations of Phillyrea angustifolia L. (Oleaceae)

Abstract

The broad aim of this work was to study intraspecific variation of seed germination in Phillyrea angustifolia L. (Oleaceae), a species with a hard (water-permeable) endocarp. Germination of seeds from six different wild populations was correlated with traits related either to seed morphology or to environmental parameters. Germination of naked seeds (seeds without endocarp) at the optimum germination conditions was similar among populations and individuals, but great differences could be detected regarding the germination of seeds with endocarp both at inter- and intra-populational levels. Differences among populations could be related to climatic parameters and to morphometric variables of seeds with endocarp. A higher germination was associated with populations growing in habitats with more severe summer (higher temperature, lower precipitation and a longer drought period) and producing elongated seeds (lower Feret ratio and roundness). Moreover, seeds from eight different individuals within a population were tested independently, and great differences regarding the germination of seeds with endocarp could be detected among individuals. Our results suggest that the morphological variation found in P. angustifolia endocarp is both under strong maternal genetic control as well as influenced by environmental factors, as indicated by the high variability among individuals within one population and the significant correlation between climate variables and seed germination among populations. Finally, it is emphasized that standardization of plant propagation protocols should take into account the degree of intraspecific variation of Mediterranean species.

Effects of Temperature and Salinity on Seed Germination of Three Common Grass Species

“…Such results could be related to the effects of ion toxicity on seed germination (Panuccio et al, 2014). The different responses of plants to salinity are likely caused by the genetic traits of these species (Vu et al, 2015;Chamorro et al, 2017) and their growing conditions (Mira et al, 2017).…”

Seed dormancy and longevity variability of Hirschfeldia incana L. during storage

“…Seed heterogeneity may be associated with ecological strategies that have evolutionary significance. Morphological heterogeneity within a population may occur in seed size, shape or colour (Baskin and Baskin, 1998; Imbert, 2002; Matilla et al , 2005; Zaidi et al , 2010), and has been related to physiological properties, including dormancy (Duran and Retamal, 1989; Rodríguez et al , 2015), germination (Puga-Hermida et al , 2003; Mira et al , 2011b; 2017), and longevity (Kochanek et al , 2009; Niedzielski et al , 2009; Nagel and Borner, 2010). Seed characteristics may also vary within plant and even fruit (Venable, 1985; Guzzon et al , 2018).…”

Maternal effects strengthen interactions of temperature and precipitation, determining seed germination of dominant alpine grass species

“…Generally, germination is highly responsive to the immediate environment of the seeds (e.g., Grime et al, 1981;Khan and Gulzar, 2003;Shahriari et al, 2014;Finch et al, 2019) as well as to the environment of their origin (e.g., Roach and Wulff, 1987;Cendán et al, 2013;Walter et al, 2016;Finch et al, 2019). Recent studies found considerable intraspecific variation in germination percentage, with populations from the warmest conditions showing the highest germination in all study treatments (Santo et al, 2015) or at least one study treatment (e.g., Ndihokubwayo et al, 2016;Bauk et al, 2017;Mira et al, 2017). Cavieres and Arroyo (2000) and Spindelbock et al (2013) found higher temperature requirements for germination in populations coming from colder, alpine conditions, which was explained as cold avoidance.…”