Seeds, Volume 1, Issue 1 (March 2022) – 6 articles

The physiological quality of pine seeds is characterized by laboratory and field germination. The present paper is intended for technologists of seed plants and specialists of forest nurseries. It offers a solution to improve the seeding characteristics of small seeds by their pre-sowing preparation. The success of reforestation activities directly depends on the quality of the seeds. The influence of seed sorting by seed size and seed coat colour has been theoretically substantiated and repeatedly tested in practice. However, the response of seeds in germination can vary depending on the year and place of seed collection. Scots pine (Pinus sylvestris L.) seeds were germinated under controlled conditions. Seedlings were obtained from seeds pre-sorted by seed coat colour into white, brown, and black groups, and further divided by size. The results of sorting by the colour of seed coat indicate a different effect of this pre-sowing treatment on the sowing qualities of seeds. Brown seed coat colour showed the highest percentage degree in the seedlots of all provenances. The seeds from the southern provenance with the brown seed coat colour shown the maximum germination. That said, the study raises new questions, indicating more comprehensive research in the future. Does the pattern of germination parameter distribution remain constant for seeds of other harvest years but of the same provenance? Does the variability of the germination factor the result of internal factors of the container location in the greenhouse? Is the genetic diversity of seedlings disturbed by sorting by size? Full article

This study aims to quantify the seed germination response of six tomato landraces to temperature; predict future climate changes relative to the baseline period (1980–2009) for studied locations in the courses of near-term (2010–2039) and mid-term (2040–2069) under two representative concentration pathways (RCP 4.5 and 8.5); assess the impact of future climate change on the final germination percentage (FGP) and time to reach 50% germination (D50) in the studied landraces. The results show that FGP is zero at 10 °C, reaches the highest value at 15–35 °C, and ceases at 36–40 °C for all landraces. The results also demonstrate that the temperature increment is 0.8–1.3 °C and 1.5–2.7 °C in the near- and mid-term, respectively, under RCP 4.5; further, this increment is 0.9–1.9 °C for the near-term and 2.3–3.4 °C for the mid-term under RCP 8.5. It estimates that the D50 takes 2.5 to 3.8 days among the locations in the baseline course. In the near term, the D50 would be 2.2 to 3.4 days under RCP 4.5 and 2.1 to 3.3 days under RCP 8.5. For the mid-term, the D50 would be projected between 1.9 and 2.9 days under RCP 4.5 and 1.8 to 2.7 days under RCP 8.5. The FGP increases up to 19.5% for Gorgan and 21.3% for Varamin under climatic scenarios relative to baseline, and it will not change in the future climate for other landraces. In conclusion, global warming can result in rapid, uniform, and complete germination in different tomato landraces. Full article

(1) Background: Peach cv. GF305 is commonly used in breeding programs due to its susceptibility to numerous viruses. In this study, we aimed to achieve a methodology for rapid and uniform seed germination of peach cv. GF305 in order to obtain vigorous seedlings; (2) Methods: A combination of cold stratification and H₂O₂ imbibition was tested on peach seeds with or without endocarp. In addition, the levels of non-enzymatic antioxidants ascorbate and glutathione as well as the hormone profile in seedling roots and shoots were determined; (3) Results: We found that H₂O₂ imbibition of peach seeds without endocarp after 8 weeks of stratification increased germination rate and resulted in seedlings displaying good vegetative growth. The H₂O₂ imbibition also affected the levels of ascorbate, glutathione, and the phytohormones abscisic acid and jasmonic acid in peach seedlings; (4) Conclusions: Although stratification periods of 12 weeks have been previously established as being appropriate for this cultivar, we have been able to reduce this stratification time by up to 4 weeks, which may have practical implication in peach nurseries. Full article

Both biotic and abiotic environmental filters drive the occurrence, distribution, and persistence of plant species. Amongst drivers that influence the distribution of plants in harsh environments, seed predation and temperature are particularly important in habitats that are prone to fire. In this study, we highlight the combined effects of predation and high temperature simulating fire to understand its effects on the germination percentage and germination speed of the fire prone species Copaifera oblongifolia. Groups of seeds attacked by the beetles Rhinochenus brevicollis and Apion sp., seeds manipulated by the ant Atta laevigata, and seeds left intact were put to germinate in controlled environments. To evaluate the effects of abiotic filters, seeds with intact elaiosomes and seeds with elaiosomes removed by the ant Atta laevigata were exposed to temperatures of 27, 60, 100, and 200 °C. The results showed that only 2.8% of the seeds attacked by R. brevicollis germinated. Seeds attacked by Apion sp. germinated faster, followed by seeds with their elaiosomes removed and seeds with intact elaiosomes. Seeds attacked by Apion sp. had the lowest germination percentage. The temperature of 200 °C killed seed embryos, whereas seeds exposed to 100 °C took longer to germinate than seeds exposed to other temperatures. Our results reveal that fire intensity and seed damage are important drivers of seed germination of C. oblongifolia. Full article

(1) Background: Seed treatment with potassium nitrate (KNO₃) has been associated with dormancy breaking, improved germination and enhanced seedling growth and uniformity in a variety of plant species. However, the KNO₃ effect seems to be dependent on plant species and treatment conditions. (2) Methods: We describe the effect of incubation of dry pea seeds with different KNO₃ concentration on water uptake kinetic, early seedling growth, antioxidant metabolism and hormone profile in pea seedlings. (3) Results: Low (0.25 mM) KNO₃ levels increased seedling water uptake and growth, whereas high (40 mM) levels decreased seedling growth. KNO₃ treatment differentially affected the antioxidant defences. Low KNO₃ levels maintained the activity of antioxidant enzymes, while high levels reduced the activity of H₂O₂-scavenging enzymes. KNO₃ induced a progressive decline in ascorbate levels and reduced (GSH) and oxidised (GSSG) glutathione. Low KNO₃ levels strongly increased GA₁ and decreased ABA in both seedlings and cotyledons, resulting in a decline in the ABA/GAs ratio. (4) Conclusions: Pea seed treatment with a low KNO₃ level promoted early seedling growth. In this process, an interaction among KNO₃, antioxidant defences and ABA/GAs ratio is proposed. Full article