Comparative Germination Ecology of Two Endemic Rhaponticum Species (Asteraceae) in Different Climatic Zones of the Ligurian and Maritime Alps (Piedmont, Italy)

Comparative studies of seed germination of closely related taxa can help increase our understanding of the ecological limitations of cold-adapted plants and forecast how they might respond to global warming. No studies exist on the relationship between thermoclimatic belts that classify mountain life zones according to bioclimatic criteria and the germination strategy of alpine plants. The aim of this study was to assess this relationship using two closely related species growing in different thermotypes and to test whether their germination responses were related to the climate at natural sites. Fresh Rhaponticum bicknellii and R. scariosum seeds were cold stratified for 0, 30, 60 and 90 days and tested for germination at 10, 15 and 20 °C. At the same time, seed burial experiments were run in the field and in the plant nursery. A GLM analysis showed that the length of cold stratification affected significantly only the germination of R. bicknellii seeds, while increasing temperatures prompted germination in both species. We found that R. bicknellii adopts a drought-avoiding germination strategy, while R. scariosum germination is favoured by warm temperatures. Our findings support the general view that alpine plants do not share common germination requirements and that any conclusions should be interpreted from a biogeographical and bioclimatic perspective. Therefore, seed germination and seedling establishment of endemic alpine species can also be predicted by looking at the bioclimate of the species’ range.

Germination strategy of Allium victorialis, a wild edible plant with high commercial potential

The spring ephemeral Allium victorialis grows naturally in Europe, Asia, and North America. Because of its pleasant taste, aroma, and nutraceutical properties, it is intensively gathered in its natural habitats by the local populations. To introduce A. victorialis as a new crop, technologies of mass-propagation and effective production must be developed. However, the biology of seed dormancy and germination in this species is not clear, and numerous attempts at controlled seed germination have not succeeded. We employed a systematic approach for seed germination of this species under controlled conditions. Two main factors, post-ripening seed age and germination temperature regimes, were studied in combination with various germination techniques. As opposed to common conceptions, our results show that the seeds of A. victorialis do not experience morphological, physical, or physiological dormancy, and are completely ready for germination immediately following ripening. Propagation of A. victorialis from seed can be performed by germination of fresh seeds at moderate (20 °C) temperatures, in a sterile planting medium with good aeration. The germination strategy, revealed in this research, opens new prospects for the development of A. victorialis as a new and useful crop.

Germination strategies of two dominant Carex species in a swamp alder forest: implications for restoration

Germination strategy is an essential mechanism that determines plant survival in previously established populations or newly colonised sites.

Germination strategies of 20 alpine species with varying seed mass and light availability

Seed germination is a central component of plant life history. To investigate the proposed role of seed size on germination strategy in plant communities, a semifield experiment was conducted in alpine meadow of the Qinghai–Tibetan Plateau, China. Interspecies relationships of seed mass and seed germination characteristics were studied under semifield conditions with different light availability. Light availability and seed mass had significant effects on final germination percentage and time to germination for studied species. There was a significant negative correlation between the strength of light required for germination and seed mass. Fifteen study species (e.g. Ligularia przewalskii, Artemisia sieversiana Willd, Tripolium vulgare Ness. and Saussurea morifolia Chen) exhibited a synchronous germination strategy. Seeds from large-seeded species, such as Dracocephalum ruyschiana, Laniophlomis rotate (Benth.) and Salvia przewalskii Maxim., were less likely to require light for germination than those of small-seeded species, such as A. sieversiana Willd, Senecio diversipinnus Ling and Saussurea mongolica (Franch.). We propose that germination strategies of small-seeded species are well suited to unpredictable environmental variation in this alpine grassland community.