Effect of Temperature on the Germination of Five Coastal Provenances of Nothofagus glauca (Phil.) Krasser, the Most Representative Species of the Mediterranean Forests of South America

Abstract

Temperature is one of the most important abiotic factors affecting seed germination, and it is strongly influenced by local site conditions. Seeds of Nothofagus glauca, an endemic and vulnerable species of the Mediterranean region of Chile and the most representative of the Mediterranean forests of South America, were collected. In this study, we evaluated the effect of temperature on different germinative attributes of five N. glauca provenances representative of their natural distribution. The seeds were treated at a constant temperature (i.e., 18 °C, 22 °C, 26 °C, or 30 °C) in the absence of light for 40 days. The results show that in all the provenances, the germination ratio and energy increase linearly with temperature until reaching an optimum temperature (i.e., 22 °C), above which they decrease severely. At 22 °C, the response of average germination speed and germination vigor was significantly higher than with the other temperatures (performance of germination start day was not clear). The base temperature was around 18 °C and the maximum, above 30 °C, which may be close to thermo-inhibition. Given the threat of climate change, it is necessary to increase research in terms of the possible adaptation of this species to increased temperatures and prolonged periods of drought

Creation and Use of Highly Adaptive Productive and Technological Red Currant Genotypes to Improve the Assortment and Introduction into Different Ecological and Geographical Zones

“…High air temperature is an important component of drought [ 27 , 28 , 29 ]. The water regime is one of the components of plant adaptation to growing conditions.…”

“…Heat, drought, and low temperatures are among the main abiotic stressors to which agricultural crops are exposed and which lead to large crop losses [ 27 , 31 , 32 ]. The critical, lethal temperature for Ribes is considered to be +50 °C [ 33 ], therefore, this temperature was chosen in this experiment to assess the heat resistance of red currant genotypes and should be taken into account when introducing them to other regions.…”

The Recruitment of the Recalcitrant-Seeded Cryptocarya alba (Mol.) Looser, Established via Direct Seeding Is Mainly Affected by the Seed Source and Forest Cover

“…Variability in germination among populations was reported in other forest species and shrubs [ 58 , 59 , 60 , 61 ] and is attributed to genetic differences and climatic and geographic effects [ 62 ]. The Mediterranean-type climate area of central Chile has a diversity of climatic conditions due to its geography and latitudinal variation in germination capacity and early performance was observed in species of the Nothofagus genus [ 61 , 63 , 64 ] and sclerophyllous species including C. alba [ 37 , 65 , 66 ]. In our study, the success of seed germination and survival of C. alba was significantly determined by the seed source, where only the local seed source CA showed some survival at the end of the experiment.…”

“…alba [ 70 ] and other species in Mediterranean zones [ 71 ]. Seed mass and/or size very often have significant effects on final germination percentage, germination rate, seedling survival and/or seedling growth, and even on resistance to intra- or interspecific competition; however, some studies have shown contrasting results [ 64 , 72 , 73 ]. Harper [ 74 ] suggested that the poorer performance of lighter seeds is due to their lower endosperm content.…”

Asociación espacial de Nothofagus antarctica y Berberis microphylla: mecanismos de facilitación sobre la regeneración arbórea en sistemas silvopastoriles

“…Arana et al, (2015) determinaron que un cambio en la temperatura del suelo puede afectar la germinación de las semillas del género Nothofagus. Santelices-Moya et al (2022) determinaron que un exceso de la temperatura del aire puede inhibir la germinación de las semillas de ñire. Por otro lado, las condiciones climáticas afectan también a la regeneración del ñire en estado de plántulas.…”