Is the benefit of larger seed provisioning on seedling performance greater under abiotic stress?

Abstract

Seed size is a relevant predictor of seed survival, seedling phenotype and species recruitment and it is generally accepted that larger seeds give rise to seedlings with improved performance. In pioneer tree species the success in seedling survival is strongly determined by resource availability, which largely varies at diverse spatial scales. Here, using a pioneer Mediterranean pine species as a model (Maritime pine, Pinus pinaster Ait.), we hypothesized that the positive effect of seed provisioning on seedling establishment and early performance may be stronger under environmental harassment, and that the progeny of lineages investing in bigger seeds would be favored in such stressful conditions. We explored the effect of seed mass on seedling traits related to germination, survival, growth and biomass partitioning by sowing preweighted seeds of known genetic background and culturing the seedlings under a range of abiotic stress conditions by experimentally modifying phosphorus (four levels, 5260 seeds) and water availability (three levels, 975 seeds) in two independent experiments. Phenotypic variation in seed mass was extremely large, with more than a tenfold change between the smallest and the largest seed. Seed mass variation showed a strong genetic component with large and significant variation both between and within populations. As expected, seed mass was a positive predictor of germination time and early seedling performance. However, contrary to our expectations, populations from more stressful sites produced smaller seeds, and the positive effect of seed mass on seedling performance was not magnified under resource limitation. Our results thus does not support that early seedling performance is favored by greater seed provisioning under resource limiting conditions.

Weight is a key factor in the physiological quality of Parapiptadenia rigida seeds

“…The effect of seed weight in survival and seedling performance may be more pronounced under conditions of abiotic stress or limited resources availability (Suárez-Vidal et al, 2017). In our study, we verified a similar trend, in which P. rigida seeds with greater weight (TSW) showed a higher tolerance to accelerated aging conditions, since they kept a stable electrical conductivity.…”

“…Therefore, P. rigida seeds with more reserves (high TSW) showed better germination performance after the accelerated aging process in laboratory and greenhouse conditions, making them more tolerant than seeds with lower weight. Seed size (weight) is an important survival predictor; phenotype and recruitment of seedlings in general have a straight relationship with seed size, being accepted that larger seeds produce seedlings with better performance (Suárez-Vidal et al, 2017).…”

“…Seed size is an important indicator of physical quality, directly related to germination, emergence and vegetative growth of plants of seminal origin (Ambika et al, 2014;Ghaffaripour et al, 2017;Yang & Wen, 2017). In general, seeds displaying larger size or density are potentially more vigorous because they usually have more reserves and they present well-formed embryos (Carvalho & Nakagawa, 2012;Suárez-Vidal et al, 2017), resulting in faster germination and proper seedling establishment. There are evidences that seed size selection of forest species can favor seedling production under nursery conditions, resulting in greater seedlings uniformity (Alves et al, 2005).…”

Inoculation of plant-growth-promoting rhizobacteria in Myracrodruon urundeuva Allemão supports in tolerance to drought stress

“…Native plants of semi-arid climate regions are often exposed to the damaging effects caused by drought stress, the main adversity for these plants, primarily in their initial growth stage, highlighting the importance of microbial-plant association such as PGPR for early tree development. According to Suárez-Vidal et al (2017) the seedling stage is the most critical, while survival depends on germination, with fast rooting during the rainy season. Thus, the purpose of inoculation of A. liporefum in M. urundeuva seeds was to present an alternative for the production of these plants, which are more tolerant to drought stress at the initial growth stage.…”

Mulching Affects Seed Set, Provisioning, and Offspring Performance of Vicia unijuga (Fabaceae)

“…Seed quality represents the overall value of a seed lot, which can be evaluated by seed mass, reserves, final germination percentage (FGP), and germination rate and by subsequent seedling growth (Hampton, 2002; Hampton et al, 2013). Seed mass is the most crucial functional trait related to the regenerative phase of a plant’s life cycle, and it affects germination and seedling growth traits, which are important for crop recruitment (Kołodziejek, 2017; Moles and Westoby, 2006; Suárez‐Vidal et al, 2017). Variation in seed mass has often been correlated with the environmental conditions of the mother plant during seed development, such as soil temperature, soil moisture, and nutrient availability, which can alter plant growth and photosynthesis and consequently alter amount of photosynthates and nutrients available for seed provisioning (Bu et al, 2007; Hampton et al, 2013; Larios and Venable, 2015; Walck et al, 2011).…”