scholarly journals Fire-Related Cues Significantly Promote Seed Germination of Some Salt-Tolerant Species from Non-Fire-Prone Saline-Alkaline Grasslands in Northeast China

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2675
Author(s):  
Shaoyang Li ◽  
Hongyuan Ma ◽  
Mark K. J. Ooi

Seed germination in response to fire-related cues has been widely studied in species from fire-prone ecosystems. However, the germination characteristics of species from non-fire-prone ecosystems, such as the saline-alkaline grassland, where fire occasionally occurs accidentally or is used as a management tool, have been less studied. Here, we investigate the effects of different types of fire cues (i.e., heat and smoke water) and their combined effect on the seed germination of 12 species from the saline-alkaline grassland. The results demonstrated that heat shock significantly increased the germination percentage of Suaeda glauca and Kochia scoparia var. sieversiana seeds. Smoke water significantly increased the germination percentage of Setaria viridis and K. scoparia seeds. However, compared with single fire cue treatments, the combined treatment neither promoted nor inhibited seed germination significantly in most species. These results suggest that fire cues can be used as germination enhancement tools for vegetation restoration and biodiversity protection of the saline-alkaline grassland.

2016 ◽  
Vol 76 (2) ◽  
pp. 367-373 ◽  
Author(s):  
A. B. Lone ◽  
R. C. Colombo ◽  
B. L. G. Andrade ◽  
L. S. A. Takahashi ◽  
R. T. Faria

Abstract The germination characteristics of the native cactus species are poorly known, being the temperature and the light the factors that the most interferes in that process. Thus, the objective of the present work was to characterize the fruits and evaluate the influence of the temperature and the light in the seed germination of Rhipsalis floccosa, Rhipsalis pilocarpa and Rhipsalis teres. The tested constant temperatures were 15, 20, 25, 30 and 35 °C and the alternate of 20-30 °C and 25-35 °C in a photoperiod of 10 hours, and with determination of the most appropriate temperature, the germination was tested in light absence. The germination percentage, the index of germination speed and medium time of germination were evaluated. For R. floccosa, the highest germination percentage was at 20 °C. For R. pilocarpa and R. teres, the highest germination percentages occurred in 15 °C and 20 °C. There was correlation to germination percentage between the three species, indicating that they had similar germination behavior. Total absence of germination was verified for the three species in condition of light absence. In conclusion, the temperature of 20 °C is the most suitable for the seed germination of R. floccosa. For the species R. pilocarpa and R. teres, the temperatures of 15 and 20 °C are the most suitable.


2012 ◽  
Vol 76 (1) ◽  
pp. 119-126 ◽  
Author(s):  
Maryam Haghighi ◽  
Zahra Afifipour ◽  
Maryam Mozafarian

The Alleviation Effect of Silicon on Seed Germination and Seedling Growth of Tomato Under Salinity StressThis study was conducted to evaluate the effectiveness of silicon (Si) application under salinity levels on seed germination and growth characteristics of tomato seeds. A laboratory experiment was performed on completely randomized design with two levels of salinity (25 and 50 mM NaCl) and 2 concentration of Si (1 and 2 mM) with 4 replications. Germination percentage, germination rate, seedling shoot and root length, fresh and dry weight of seedling and mean germination time was measured. Seed germination ofLycopersicon esculentumL. was significantly affected by salinity levels, Si and their interaction. Germination characteristics of tomato seeds decreased drastically by increasing NaCl concentrations. However, 1 mM Si had positive effects on seed germination characteristics and improved germination percentage, germination rate and mean germination time. Si alleviated the harmful effect of salinity stress on tomato seed germination at almost all germination characteristics.


1983 ◽  
Vol 36 (5) ◽  
pp. 646 ◽  
Author(s):  
J. H. Everitt ◽  
M. A. Alaniz ◽  
J. B. Lee

1992 ◽  
Vol 2 (3) ◽  
pp. 163-168 ◽  
Author(s):  
C. A. Thanos ◽  
K. Mitrakos

AbstractSeed germination of watermelon (Citrullus lanatus cv. Sugar Baby) was fully suppressed by intermittent far-red (FR) irradiation (1 min every 30 min). When the intervening dark period was increased, a linearly increasing final germination percentage was obtained. However, a 4-day intermittent FR treatment induced phytochrome-controlled dormancy and the longer the dark interval the deeper was the dormancy of the non-germinated seeds. When seeds were soaked in a fully inhibitory osmotic solution, no dormancy was imposed. However, a single FR pulse at the time of transfer induced partial, secondary dormancy; the kinetics of the imposition of dormancy followed a negative exponential curve (half-life 1.5 days; 3 days for the cultivar Crimson Sweet). Seeds osmotreated for 10 days in darkness and subsequently dehydrated (with and without a final FR pulse) acquired germination characteristics similar to those in light-requiring and dark-germinating achenes, respectively, of the lettuce cultivar Grand Rapids. In the light-requiring osmomanipulated seed population, the induction of germination was brought about by the low-energy reaction of phytochrome, chilling, dry storage and decoating. The transformation through osmomanipulation of the dark-germinating watermelon seeds (the inhibition of which required prolonged exposure to light) to positively or negatively photosensitive seeds (that responded to brief light pulses), might be attributed to the slow relaxation of existing meta-Fa and meta-Rb phytochrome intermediates to Pfr upon hydration.


2013 ◽  
Vol 61 (5) ◽  
pp. 404 ◽  
Author(s):  
Gao-Lin Wu ◽  
Guo-Zhen Du ◽  
Zhi-Hua Shi

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.


HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 787D-787
Author(s):  
J. Ryan Stewart* ◽  
William R. Graves

Carolina buckthorn (Rhamnus caroliniana Walt.) is ornamental and could be promoted as a stress-resistant shrub for horticultural landscapes. Its status as a relative of invasive species, including common buckthorn (Rhamnus cathartica L.), raises concerns regarding the environmental consequences of planting Carolina buckthorn outside of its natural habitat. To assess the ease of propagating Carolina buckthorn from seed, and to gather data relevant to assessments of invasiveness, we compared seed-germination characteristics between the two species. Seeds of Carolina buckthorn were collected from native populations in Missouri, Oklahoma, and Texas. Seeds of common buckthorn were collected from populations in Iowa. We stratified seeds of both species for up to 112 days at 4 °C. Germination at 20 °C then was evaluated for 56 days. Over stratification durations, 40% and 71% of seeds of Carolina buckthorn and common buckthorn germinated, respectively. Stratification for 112 days optimized germination value for Carolina buckthorn, but stratification for 42, 56, 84, and 112 days evoked similar germination percentages. Seeds of Carolina buckthorn from Oklahoma germinated at a higher percentage (56%) than did seeds from Missouri (25%). Neither germination value nor germination percentage of common buckthorn was influenced by stratification. We conclude that seeds of Carolina buckthorn are more recalcitrant than are seeds of common buckthorn. This suggests that Carolina buckthorn, particularly those from Missouri with low reproductive success, may be less invasive than their Eurasian kin. Horticulturists can optimize germination percentage of Carolina buckthorn by cold-stratifying seeds for as little as 42 days, but 112 days optimizes germination value.


HortScience ◽  
2009 ◽  
Vol 44 (3) ◽  
pp. 751-756 ◽  
Author(s):  
Michael W. Bairu ◽  
Manoj G. Kulkarni ◽  
Renée A. Street ◽  
Rofhiwa B. Mulaudzi ◽  
Johannes Van Staden

A study was done to investigate the effects of some physical and chemical factors on growth and development of Aloe ferox ex vitro and in vitro. The effects of light, temperature, and smoke–water on seed germination, ex vitro seedling growth requirements, and effect of germination medium and cytokinins on shoot induction and multiplication in vitro were investigated. The highest germination percentage of A. ferox seeds was recorded between 15 and 30 °C. Seed germination was inhibited at 10 and 35 °C. There was a nonsignificant increase in germination percentage (78%) for seeds that were germinated under constant dark conditions. Smoke–water-treated seeds showed significant improvement in percentage germination (80%) over the control (66%) at 25 °C with a 16-h photoperiod. Seedlings of A. ferox subjected to alternating temperatures (30/15 °C) or being irrigated three times weekly at 25 °C showed better seedling growth. In an in vitro experiment, seedlings germinated in distilled water and one-tenth strength Murashige and Skoog medium had superior shoot induction competence compared with the other germination media. The cytokinins meta-Topolin (mT) and meta-Topolin riboside (mTR) at 5 μm gave significantly higher shoot multiplication rates compared with the control and benzyladenine (BA)-treated plants. A higher abnormality index was recorded for BA-treated plants. The findings of this study will be beneficial for commercial propagation of Aloe ferox.


2021 ◽  
Vol 12 ◽  
Author(s):  
Hao Zhang ◽  
Mingfang Hu ◽  
Hongyuan Ma ◽  
Li Jiang ◽  
Zhenyong Zhao ◽  
...  

The period between seed germination and seedling establishment is one of the most vulnerable stages in the life cycle of annuals in the saline environments. Although germination characteristics of Suaeda salsa seeds have been reported, the comparative germination patterns of dimorphic seeds and seedling growth to different abiotic stresses remain poorly understood. In this study, germination responses of dimorphic seeds to light and temperature were compared. Meanwhile, responses of dimorphic seeds and thereafter seedlings of S. salsa to different concentrations of NaCl and Na2SO4 were also tested. The results showed that the light did not significantly affect germination percentage of brown seeds, but significantly promoted germination of black seeds. Brown seeds could reach high germination percentage over a wide temperature range, however, germination of black seeds gradually increased with the increase of temperature. Brown seeds had higher germination percentage and velocity than black seeds under the same salt conditions. However, black seeds had higher recovery germination than brown seeds when transferred to deionized water. Young seedlings had lower salt tolerance than germinating seeds. At the same concentrations, Na2SO4 had stronger inhibitory effect on seed germination and seedling growth than NaCl. This study comprehensively compared germination traits of dimorphic seeds and seedling growth of S. salsa, and then developed a conceptual model to explain their adaptation to harsh saline environment.


HortScience ◽  
2006 ◽  
Vol 41 (3) ◽  
pp. 612-617 ◽  
Author(s):  
Rowan D. Briscoe ◽  
Rajasekaran R. Lada ◽  
Claude D. Caldwell ◽  
Kevin Sibley

Stand establishment is critical for optimizing yield and quality in carrots. Low soil temperatures and moisture conditions often challenge seed germination and emergence. Providing an artificial exosperm with appropriate germination promoters, stress conditioners and growth invigorators to the seed may facilitate uniform germination and emergence. Germination patterns and velocity of germination of `Oranza' carrot was studied. Seeds were mixed in different types of gels at various ratios and incubated at either 5 or 20 °C. Gels used were Laponite RD, Laponite RDS, guar gum, algenic acid, and agar. Data on germination percentage was collected and the velocity of germination was calculated. Germination was delayed at 5 °C. Both at 5 and 20 °C, Laponite RD promoted and enhanced germination and vigor, and resulted in the highest mean germination percentage (90% at 20 °C and 89% at 5 °C). Laponite RD at 2.5% has shown an overall advantage in germination percentage (94% at 20 °C and 87% at 5 °C) over other gel types and concentrations.


2019 ◽  
pp. 49-61
Author(s):  
Reyhaneh Azimi ◽  
Mohammad Kia Kianian ◽  
Mohammad Pessarakli

Improvement in the rate and amount of germination of seeds has a very important effect on the establish-ment of primary seedlings and the increase of rangeland production. The rapid and uniform germination of seeds leads to the successful establishment of plants. The use of nanoscale materials can help germinate faster seeds. Therefore, in this study, the effects of TiO2 nanoparticles in concentrations of 0, 10, 20, 30, 40, 60 and 80 mg / l on the rate and speed of seed germination of Ziziphora clinopodioides Lam. paid. This design was carried out in a completely randomized design with four replications for 20 days at a constant temperature of 20°C under 12 hours of light and 12 hours of darkness at the Germinator of Natural Resources Faculty of the Ferdowsi University of Mashhad. The results showed that germination percentage of treated seeds with TiO2 nanoparticles increased to 23% ppm compared to control treatment. Also, in other concentrations of other nanoparticles, there was a positive effect on speed and germination percentage, so that the effect of different concentrations of nanoparticles on germination characteristics of Ziziphora clinopodioides Lam. seeds was significant. The highest germination percentage was observed in the concentration of 30 ppm and the lowest germination rate at 30 and 20 ppm concentrations. In high concentrations of TiO2 nanoparticles, no positive effects were observed on the germination characteristics of seed Ziziphora clinopodioides Lam. To conclude the use of TiO2 nanoparticles can be improved by improving the seed germination properties of the medicinal plant Ziziphora clinopodioides Lam. that cause increases plant’s establishment in natural areas.


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