Responses of a legume to inbreeding and the intensity of novel and familiar stresses

Abstract

It is often assumed that the negative effects of inbreeding on fitness (inbreeding depression, ID) are particularly strong under stressful conditions. However, ID may be relatively mild under types of stress that plant populations have experienced for a long time, because environment‐specific deleterious alleles may already have been purged. We examined the performance of open‐ and self‐pollinated progeny of the short‐lived calcareous grassland plant Anthyllis vulneraria under three intensities of each of five types of stress. Drought, nutrient deficiency, and defoliation were chosen as stresses typical for the habitat of origin, while shade and waterlogging were expected to be novel, unfamiliar stresses for A. vulneraria. The stresses reduced plant biomass by up to 91%, and the responses of the plants were mostly in line with the functional equilibrium hypothesis. There was significant ID in biomass (δ = 0.17), leaf chlorophyll content, and the number of root nodules of the legume, but the magnitude of ID was independent of the stress treatments. In particular, there was no significant interaction between inbreeding and the intensity of any stress type, and ID was not higher under novel than under familiar stresses. In addition, phenotypic plasticity in biomass allocation, leaf functional traits and in root nodulation of the legume to the various stress treatments was not influenced by inbreeding. Our findings do not support the common hypothesis of stronger ID under stressful environments, not even if the stresses are novel to the plants.

Biomass partitioning in response to intraspecific competition depends on nutrients and species characteristics: A study of 43 plant species

“…Gibert et al., 2019). This rhizobia–legume interaction strongly depends on the environment (Araújo et al., 2015; Batstone et al., 2020; Heath et al., 2010; Rehling et al., 2019; Zahran, 1999), but is particularly beneficial at high light, but low nutrient conditions (Friel & Friesen, 2019; Lau et al., 2012; Taylor & Menge, 2018). Second, the life span of a plant represents a trade‐off between survival and reproduction (Friedman, 2020) that affects its biomass allocation and response to different environments (Eziz et al., 2017; Husáková et al., 2018; Poorter et al., 2015).…”

Low levels of inbreeding depression and enhanced fitness in cleistogamous progeny in the annual plantTriodanis perfoliata

“…populations that have generally low inbreeding depression values(Rehling et al 2019). A study investigating inbreeding depression in the field in this species would be complementary to this work, but would not be free of potential bias nor would it necessarily provide more accurate estimates.…”

Epigenetic Changes Occurring in Plant Inbreeding

“…In Clarkia tembloriensis , greater inbreeding depression was observed in the greenhouse than under field conditions [ 106 ]. According to Rehling et al [ 107 ], the level of ID may be low in the case of stresses, to which plant populations were exposed for a long time, as deleterious alleles specific to the environment may have already been eliminated.…”