Warm temperature conditions restrict the sexual reproduction and vegetative growth of the spring ephemeral Gagea lutea (Liliaceae)

Abstract

The responses of reproduction and growth to climate warming are important issues to predict the fate of plant populations at high latitudes. Spring ephemerals inhabiting cool-temperate forests grow better under cool conditions, but how reproductive performance is influenced by warm weather is unclear. The phenological and physiological responses of reproduction and vegetative growth to warm temperature and light conditions were evaluated in the spring ephemeral Gagea lutea. Leaf and bract physiological activities, bulb growth, and seed production were compared among reproductive plants grown in forest, open, and greenhouse (GH; warming manipulation in the open site) plots. In vitro pollen germination ability was tested under various temperatures. In the GH, leaf and bract photosynthetic activities decreased rapidly at the fruiting stage, but dark respiration rates remained high, resulting in higher carbon exhaust in warm conditions. Both leaf and bract sizes and their longevities were reduced in the GH. Annual bulb growth was largest in the forest plot and smallest in the GH plot. Pollen germination was strongly inhibited at high temperature (30 degrees C). Fruit and seed productions were decreased only in the GH plot. Both vegetative and reproductive activities were negatively affected by warm temperature, resulting in less vegetative growth and lower seed-set, whereas an understory habitat was beneficial for vegetative growth and showed similar seed production to an open habitat over the experimental period. Decreasing population dynamics of spring ephemerals was predicted in response to future warming climate not only by growth inhibition but also by restriction of seed production

Cytogeography of the East Asian Tulips (Amana, Liliaceae)

“…Diploids occur at higher elevations (Husband and Sabara, 2003 [47]; Schönswetter et al, 2007 [48]) and lower minimum temperatures (Pockman and Sperry, 1997 [49]) than polyploids, which suggests that ecological sorting based on cold tolerance can occur between cytotypes. Previous studies have shown that spring ephemerals inhabiting cool-temperate forests grow better under cool conditions, when under warm temperature, both vegetative and reproductive activities were negatively affected, resulting in less vegetative growth and lower seed-set (Sunmonu and Kudo, 2015 [50]). These previous findings together with our results imply that the ancestor of the genus Amana might be a diploid that originated in a temperate region and later migrated south to the subtropical region (perhaps during the Pleistocene glacial epoch).…”

Ecophysiological and Growth-Related Traits of Two Geophytes Three Years after the Fire Event in Grassland Steppe

“…Spring ephemerals are a group of plants within the geophyte assemblage that commonly form specific vernal synisiae of the temperate forest understory or dry grassland gaps [ 58 ]. Despite their common ecological requirements, several studies confirmed subtle differences among coexisting species in terms of emergence, flowering time, photosynthetic performance, and biomass allocation to optimize the use of limited resources, specifically light before upper canopy closure [ 41 , 59 , 60 , 61 , 62 , 63 ]. The life span of dry grassland spring geophytes is limited by both predictable periodical environmental conditions (lack of light due to development of surrounding vegetation, lack of water due to beginning of dry season and presence of more competitors, overgrazing) and additional disturbances (management practices, fire events) [ 27 , 40 , 64 , 65 , 66 ].…”

An Unexplored Side of Regeneration Niche: Seed Quantity and Quality Are Determined by the Effect of Temperature on Pollen Performance

“…The generally accepted extreme sensitivity of pollen to temperature stress rests mainly on the experiments carried out with domesticated plant species and their numerous cultivars (e.g., rice and cotton Matsui and Omasa, 2002 ; Kakani et al, 2005 ) or a very few indoor-cultivated model species, such as Arabidopsis thaliana ( Boavida and McCormick, 2007 ). In contrast, studies on microgametophyte performance in wild species under different temperature conditions are extremely scarce and usually limited to very few number of taxa in studies where a large number of species were studied ( Pigott and Huntley, 1981 ; McKee and Richards, 1998 ; Steinacher and Wagner, 2012 ; Sunmonu and Kudo, 2015 ), but see Rosbakh and Poschlod, 2016 ; Wagner et al, 2017 . It is still not clear whether the results of such studies can be generalized into natural systems since a high number of mutants lacking of specific adaptations to the environmental conditions of the growing sites were used in the experimental populations ( Stephenson and Bertin, 1983 ; Lyndon, 1992 ).…”