scholarly journals Seed Germination in Alpine Meadow Steppe Plants from Central Tibet in Response to Experimental Warming

2020 ◽  
Vol 12 (5) ◽  
pp. 1884
Author(s):  
Xiangtao Wang ◽  
Ben Niu ◽  
Xianzhou Zhang ◽  
Yongtao He ◽  
Peili Shi ◽  
...  
Keyword(s):  
Seed Germination ◽  
Community Assembly ◽  
Alpine Meadow ◽  
Common Species ◽  
Germination Percentage ◽  
The Tibetan Plateau ◽  
Meadow Steppe ◽  
Stipa Purpurea ◽  
Steppe Plants ◽  
Central Tibet

Clarifying the effects of climate warming on seed germination is critical for predicting plant community assembly and species renewal, especially in alpine grassland ecosystems where warming is occurring faster than in other biomes globally. We collected matured seeds of 19 common species from a typical alpine meadow steppe community in Central Tibet. Seeds were germinated in three incubators with manipulated day-night temperatures to impose three treatments: (1) theoretically optimal values of 25/15 °C, (2) temperatures observed in the field (control), and (3) a warming of 3 °C above the observed temperatures. We calculated seed germination percentage (SGP) and mean germination time (MGT) per species at different treatments. Our results showed that SGPs of Stipa capillacea, Kobresia macrantha, Potentilla saundersiana, Saussurea tibetica, Pedicularis kansuensis, and Androsace graminifolia were higher under the warming treatment than under control. Among them, the MGTs of S. capillacea, K. macrantha, and And. graminifolia were significantly shortened, while the MGT of Pe. kansuensis was significantly lengthened by warming of 3 °C. Significant decreases in MGT induced by warming were only observed for Festuca coelestis and Anaphalis xylorhiza. Additionally, the treatment with theoretically optimal temperatures restrained germination of Stipa purpurea, S. capillacea, F. coelestis, and Sa. tibetica seeds but promoted germination of K. macrantha, Astragalus strictus, P. saundersiana, Potentilla bifurca, Pe. kansuensis, Swertia tetraptera, Pleurospermum hedinii, and And. Graminifolia seeds, when compared with the control and warming treatments. Therefore, the response of seed germination to warming differs among alpine species, implying that future warming could result in significant changes in community assembly of alpine grasslands on the Tibetan Plateau.

Comparing the relationship between seed germination and temperature for Stipa species on the Tibetan Plateau

Botany ◽  
2014 ◽  
Vol 92 (12) ◽  
pp. 895-900 ◽  
Author(s):  
Shihai Yang ◽  
Xiong Li ◽  
Yunqiang Yang ◽  
Xin Yin ◽  
Yongping Yang
Keyword(s):  
Seed Germination ◽  
Tibetan Plateau ◽  
The Tibetan Plateau ◽  
Alpine Steppe ◽  
Stipa Purpurea ◽  
Germination Characteristics ◽  
Laboratory Investigations ◽  
Alternating Temperature ◽  
Species Specific ◽  
The Relationship

Alpine steppe grasslands dominated by Stipa species (Poaceae) on the Tibetan Plateau are important model ecosystems. Here, we present data on seed germination of three typical Stipa species (Stipa purpurea Griseb., Stipa glareosa P.A.Smirn., and Stipa capillacea Keng) from the northern core region of the Tibetan Plateau. We carried out laboratory investigations of germination behavior under both constant and alternating temperatures. Germination varied significantly with temperature. Under constant temperature, we found that temperature and species, but not their interaction, had significant effects on seed germination. Under alternating temperatures, species had a significant effect on seed germination, whereas the effects of alternating temperature and the interaction between species and alternating temperature were not significant. In addition, light and the interaction of light and species had no significant effect on seed germination; however, species had a significant effect, implying that Stipa species on the Tibetan Plateau are not inhibited by light. Base temperatures of S. glareosa, S. purpurea, and S. capillacea were 1.0 °C, 0.1 °C, and –1.4 °C, respectively, with corresponding thermal times at suboptimal temperatures of 233 °C-day, 154 °C-day, and 263.2 °C-day. Our results suggest that Stipa seed germination characteristics are adaptions to a harsh environment and are species-specific.

scholarly journals Effect of Nitrogen Addition on Selection of Germination Trait in an Alpine Meadow on the Tibet Plateau

2021 ◽  
Vol 12 ◽  
Author(s):  
Kun Liu ◽  
Yang Liu ◽  
Zhilong Zhang ◽  
Shiting Zhang ◽  
Carol C. Baskin ◽  
...  
Keyword(s):  
Seed Germination ◽  
Alpine Meadow ◽  
Germination Rate ◽  
Nitrogen Addition ◽  
Germination Percentage ◽  
N Addition ◽  
Percentage Germination ◽  
Alpine Meadows ◽  
Environmental Filter ◽  
Germination Traits

Seed germination requirements may determine the kinds of habitat in which plants can survive. We tested the hypothesis that nitrogen (N) addition can change seed germination trait-environmental filter interactions and ultimately redistribute seed germination traits in alpine meadows. We determined the role of N addition on germination trait selection in an alpine meadow after N addition by combining a 3-year N addition experiment in an alpine meadow and laboratory germination experiments. At the species level, germination percentage, germination rate (speed) and breadth of temperature niche for germination (BTN) were positively related to survival of a species in the fertilized community. In addition, community-weighted means of germination percentage, germination rate, germination response to alternating temperature and BTN increased. However, germination response to wet-cold storage (cold stratification) and functional richness of germination traits was lower in alpine meadows with high-nitrogen addition than in those with no, low and medium N addition. Thus, N addition had a significant influence on environmental filter-germination trait interactions and generated a different set of germination traits in the alpine meadow. Further, the effect of N addition on germination trait selection by environmental filters was amount-dependent. Low and medium levels of N addition had less effect on redistribution of germination traits than the high level.

Effects of sodium, magnesium and calcium salts on seed germination and radicle survival of a halophyte, Kalidium caspicum (Chenopodiaceae)

2002 ◽  
Vol 50 (2) ◽  
pp. 163 ◽  
Author(s):  
Kazuo Tobe ◽  
Xiaoming Li ◽  
Kenji Omasa
Keyword(s):  
Seed Germination ◽  
Common Species ◽  
Germination Percentage ◽  
Western China ◽  
Cation Composition ◽  
Sodium Magnesium ◽  
Saline Habitats ◽  
Ca Ions ◽  
The Media ◽  
Salt Toxicity

Kalidium caspicum (L.) Ung.-Sternb. is a common species of highly saline habitats of north-western China, which in previous germination research has been shown to be rather sensitive to NaCl toxicity. To investigate the effects of different salts on the seed germination and radicle survival of this halophytic shrub, seeds were incubated in various salt (NaCl, Na2SO4, MgCl2, or MgSO4 with or without CaCl2) or polyethylene glycol-6000 solutions. The germination percentage and the percentage of emerging radicles surviving to a length of at least 4 mm were examined. The survival of K. caspicum radicles depended mainly on the cation composition of the media: both Na+ and Mg2+ had toxic effects on the radicles, while Ca2+ alleviated the toxicity of these cations. Mg2+ was more toxic than Na+ and a higher concentration of Ca2+ was needed to alleviate its toxicity. It was suggested that the establishment of seedlings of K. caspicum in the field is facilitated by the marked alleviation of salt toxicity by Ca2+ and that the proportion of soluble Na, Mg and Ca ions in the soil determines the distribution of K. caspicum in the field.

scholarly journals Effect of H2O-Based Low-Pressure Plasma (LPP) Treatment on the Germination of Bambara Groundnut Seeds

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 338
Author(s):  
Naeem Ahmed ◽  
Asad Masood ◽  
Kim S. Siow ◽  
M. F. Mohd Razip Wee ◽  
Rahmat Zaki Auliya ◽  
...  
Keyword(s):  
Food Security ◽  
Seed Germination ◽  
Chemical Modification ◽  
Low Pressure ◽  
Germination Percentage ◽  
Bambara Groundnut ◽  
Pressure Plasma ◽  
Low Pressure Plasma ◽  
Amine Groups

In general, seed germination is improved by low-pressure plasma (LPP) treatment using precursors such as air, nitrogen, argon, or water (H2O). Here, H2O-based LPP treatment using the optimized parameters of 10 W and 10 s improves the germination of Bambara groundnut seeds by 22%. LPP increases the wettability and roughness of the seed hilum while oxidizing the surface with carboxyl and amine groups. In this H2O-based treatment of Bambara groundnut seeds, combinatory etching and chemical modification facilitated the imbibition process and increased the germination percentage. The success of this method has the potential to be scaled up to solve food security with seeds otherwise facing germination-related issues.

scholarly journals Asymbiotic germination of Vanilla planifolia in relation to the timing of seed collection and seed pretreatments

2021 ◽  
Vol 62 (1) ◽  
Author(s):  
Chih-Hsin Yeh ◽  
Kai-Yi Chen ◽  
Yung-I. Lee
Keyword(s):  
Seed Germination ◽  
Seed Development ◽  
Seed Coat ◽  
Germination Percentage ◽  
Vanilla Planifolia ◽  
Outermost Layer ◽  
Seed Collection ◽  
Seed Pretreatment ◽  
Immature Seeds ◽  
Mature Seeds

Abstract Background Vanilla planifolia is an important tropical orchid for production of natural vanilla flavor. Traditionally, V. planifolia is propagated by stem cuttings, which produces identical genotype that are sensitive to virulent pathogens. However, propagation with seed germination of V. planifolia is intricate and unstable because the seed coat is extremely hard with strong hydrophobic nature. A better understanding of seed development, especially the formation of impermeable seed coat would provide insights into seed propagation and conservation of genetic resources of Vanilla. Results We found that soaking mature seeds in 4% sodium hypochlorite solution from 75 to 90 min significantly increased germination. For the culture of immature seeds, the seed collection at 45 days after pollination (DAP) had the highest germination percentage. We then investigated the anatomical features during seed development that associated with the effect of seed pretreatment on raising seed germination percentage. The 45-DAP immature seeds have developed globular embryos and the thickened non-lignified cell wall at the outermost layer of the outer seed coat. Seeds at 60 DAP and subsequent stages germinated poorly. As the seed approached maturity, the cell wall of the outermost layer of the outer seed coat became lignified and finally compressed into a thick envelope at maturity. On toluidine blue O staining, the wall of outer seed coat stained greenish blue, indicating the presence of phenolic compounds. As well, on Nile red staining, a cuticular substance was detected in the surface wall of the embryo proper and the innermost wall of the inner seed coat. Conclusion We report a reliable protocol for seed pretreatment of mature seeds and for immature seeds culture based on a defined time schedule of V. plantifolia seed development. The window for successful germination of culturing immature seed was short. The quick accumulation of lignin, phenolics and/or phytomelanins in the seed coat may seriously inhibit seed germination after 45 DAP. As seeds matured, the thickened and lignified seed coat formed an impermeable envelope surrounding the embryo, which may play an important role in inducing dormancy. Further studies covering different maturity of green capsules are required to understand the optimal seed maturity and germination of seeds.

scholarly journals Effect of Environmental Factors on the Germination and Emergence of Drunken Horse Grass (Achnatherum inebrians)

Weed Science ◽  
2020 ◽  
pp. 1-29
Author(s):  
Yonghuan Yue ◽  
Guili Jin ◽  
Weihua Lu ◽  
Ke Gong ◽  
Wanqiang Han ◽  
...  
Keyword(s):  
Seed Germination ◽  
Environmental Factors ◽  
Abiotic Factors ◽  
Seedling Emergence ◽  
Management Strategies ◽  
Germination Percentage ◽  
Western China ◽  
Burial Depth ◽  
Achnatherum Inebrians ◽  
Water Ph

Abstract Drunken horse grass [Achnatherum inebrians (Hance) Keng] is a perennial poisonous weed in western China. A comprehensive understanding of the ecological response of A. inebrians germination to environmental factors would facilitate the formulation of better management strategies for this weed. Experiments were conducted under laboratory conditions to assess the effects of various abiotic factors, including temperature, light, water, pH and burial depth, on the seed germination and seedling emergence of A. inebrians. The seeds germinated at constant temperatures of 15, 20, 25, 30, 35°C and in alternating-temperature regimes of 15/5, 20/10, 25/15, 30/20, 35/25, 40/30°C, and the seed germination percentages under constant and alternating temperatures ranged from 51% to 94% and 15% to 93%, respectively. Maximum germination occurred at a constant temperature of 25°C, and germination was prevented at 45/35°C. Light did not appear to affect seed germination. The germination percentage of seeds was more than 75% in the pH range of 5 to 10, with the highest germination percentage at pH 6. The seeds germinated at osmotic potentials of 0 MPa to -1.0 MPa, but decreasing osmotic potential inhibited germination, with no germination at -1.2MPa. After 21 d of low osmotic stress, the seeds that did not germinate after rehydration had not lost their vitality. The seedling emergence percentage was highest (90%) when seeds were buried at 1 cm but declined with increasing burial depth and no emergence at 9 cm. Deep tillage may be effective in limiting the seed germination and emergence of this species. The results of this study provide useful information on the conditions necessary for A. inebrians germination and provide a theoretical basis for science-based prediction, prevention and control of this species.

scholarly journals The effect of environmental and phylogenetic drivers on community assembly in an alpine meadow community

Ecology ◽  
2012 ◽  
Vol 93 (11) ◽  
pp. 2321-2328 ◽  
Author(s):  
Zhongling Yang ◽  
Jeff R. Powell ◽  
Chunhui Zhang ◽  
Guozhen Du
Keyword(s):  
Community Assembly ◽  
Alpine Meadow

Responses of ecosystem respiration and its components to fertilization in an alpine meadow on the Tibetan Plateau

2013 ◽  
Vol 56 ◽  
pp. 101-106 ◽  
Author(s):  
Jing Jiang ◽  
Ning Zong ◽  
Minghua Song ◽  
Peili Shi ◽  
Weiling Ma ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Alpine Meadow ◽  
Ecosystem Respiration ◽  
The Tibetan Plateau

The Effect of High Concentrations of Ethylene on Seed Germination of Douglas Fir (Pseudotsugamenziesii (Mirb.) Franco)

1975 ◽  
Vol 5 (3) ◽  
pp. 419-423 ◽  
Author(s):  
Carey Borno ◽  
Iain E. P. Taylor
Keyword(s):  
Seed Germination ◽  
Germination Rate ◽  
Inhibitory Effect ◽  
Germination Percentage ◽  
Douglas Fir ◽  
Control Treatment ◽  
Continuous Exposure ◽  
Short Term ◽  
Short Term Exposure ◽  
High Concentrations

Stratified, imbibed Douglas fir (Pseudotsugamenziesii (Mirb.) Franco) seeds were exposed to 100% ethylene for times between 0 and 366 h. Germination rate and germination percentage were increased by treatments up to 48 h. The 12-h treatment gave largest stimulation; 30% enhancement of final germination percentage over control. Treatment for 96 h caused increased germination rate for the first 5 days but reduced the germination percentage. Germinants were subject to continuous exposure to atmospheres containing 0.1 – 200 000 ppm ethylene in air, but it did not stimulate growth, and the gas was inhibitory above 100 ppm. Although some effects of high concentrations of ethylene may have been due to the lowering of oxygen supplies, this alone was insufficient to account for the full inhibitory effect. The mechanism of stimulation by short-term exposure to ethylene is discussed.

Factors affecting red-osier dogwood seed germination

1992 ◽  
Vol 70 (5) ◽  
pp. 1012-1016 ◽  
Author(s):  
S. N. Acharya ◽  
C. B. Chu ◽  
R. Hermesh ◽  
G. B. Schaalje
Keyword(s):  
Seed Germination ◽  
Germination Percentage ◽  
Collection Site ◽  
Moisture Condition ◽  
Seed Formation ◽  
Factors Affecting ◽  
Year Effect ◽  
Wide Range ◽  
Cornus Stolonifera ◽  
Moisture Conditions

Seeds from 55 populations of native Alberta red-osier dogwood (Cornus stolonifera Michx.) were collected over 2 years (1984 and 1985) to determine the range of variability for seed germination and the effect of ecoregion and moisture conditions in the collection sites on this trait. Each year the unscarified seeds were stored at 3 °C for 30 days, stratified at 3 °C for an additional 30 days and then incubated on an 8 h light: 16 h dark cycle at a temperature of 25:10 °C (light:dark) for germination. A wide range of germination percentages was observed among populations collected in any 1 year. However, the variability was not due to the ecoregion or moisture condition of the collection site. Germination percentage of populations collected in 1984 and 1985 formed five and seven groups, respectively. A study involving eight sites that were common to 1984, 1985, and 1986 revealed a significant effect of population on seed germination. This population effect was not obscured by the combined effects of year, precipitation, temperature, and seed size. The year effect was significant only when population was used as a covariate. Precipitation during seed formation significantly influenced germination performance even after adjustments were made for population and year. Seed germination in red-osier dogwood appears to be influenced by the population from which the seeds are collected and by yearly environmental fluctuations. Therefore, germination studies in this species must include seeds from diverse populations collected over several years. Key words: red-osier dogwood, Cornus stolonifera Michx., germination, population, environment.

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