Caryopsis dormancy, germination and seedling emergence in sand, of Leymus racemosus (Poaceae), a perennial sand-dune grass inhabiting the Junggar Basin of Xinjiang, China

2004 ◽  
Vol 52 (4) ◽  
pp. 519 ◽  
Author(s):  
Zhenying Huang ◽  
Ming Dong ◽  
Yitzchak Gutterman
Keyword(s):  
Seedling Emergence ◽  
Perennial Grass ◽  
Junggar Basin ◽  
Dry Weight ◽  
Germination Percentage ◽  
Burial Depth ◽  
Physiological Dormancy ◽  
Leymus Racemosus ◽  
Different Depths ◽  
Dune Grass

Leymus racemosus (Lam.) Tzvel. (Poaceae), wild rye, is an endangered, but economically important, perennial grass. It is mainly distributed in the moving or semistabilised sand in deserts of the Junggar Basin in Xinjiang, China. Freshly harvested caryopses are in non-deep physiological dormancy, causing slow and low germination. Six weeks of cold stratification at 5�C is required for the highest germination percentage to be reached at 25–30�C. Scarifying the fruit coat, or artificial removal of different proportions of the endosperm, also increases caryopsis germination. The greater the proportion of the endosperm that was removed, the higher the percentage of germination reached. However, the dry weight of the seedlings and the rate of root and shoot lengthening were significantly influenced by the proportion of the endosperm that remained on the caryopses.The influences of caryopsis size, or of the proportion of remaining endosperm, on germination and seedling emergence from different depths in sand were studied. The percentage of germination was negatively influenced by burial depth, but not by caryopsis size or the proportion of the endosperm that remained. Seedling emergence was negatively related to both burial depth and caryopsis or endosperm sizes. Seedlings from the smallest seeds or from caryopses with 75% endosperm removed did not emerge from 4 cm, and no seedlings from any of the treatments emerged from a depth of 8 cm.

Seedling desiccation tolerance of Leymus racemosus (Poaceae) (wild rye), a perennial sand-dune grass inhabiting the Junggar Basin of Xinjiang, China

2004 ◽  
Vol 14 (2) ◽  
pp. 233-239 ◽  
Author(s):  
Zhenying Huang ◽  
Yitzchak Gutterman
Keyword(s):  
Desiccation Tolerance ◽  
Sand Dune ◽  
Sand Dunes ◽  
Perennial Grass ◽  
Junggar Basin ◽  
Seedling Development ◽  
Ecological Implications ◽  
Leymus Racemosus ◽  
Seedling Desiccation Tolerance ◽  
Dune Grass

Leymus Racemosus, The Mammoth Wild Rye, Is A Rhizomatous Perennial Grass, Mainly Distributed In The Moving Or Semi-Stabilized Sand Dunes In Deserts Of The Junggar Basin In Xinjiang, China. The Revival Ability Of The Young Seedling After Periods Of Desiccation Can Be Influenced By Several Factors: (1) The Stage Of Seedling Development – The Later The Stage At Dehydration, The Longer The Root Length And The Lower Is The Percentage Of Seedlings That Survive; (2) The Length Of The Period Of Desiccation – The Longer The Period That The Seedlings Are Under Desiccation, The Lower Is The Percentage Of Seedlings That Survive; (3) Endosperm Size – The Smaller The Proportion Of Endosperm That Remains In The Caryopses, The Lower Is The Percentage Of Seedlings That Revive, Determined By (A) The Stage Of Seedling Development, And (B) The Proportion Of The Endosperm That Is Removed By Cutting; And (4) Caryopsis Size – The Larger The Polymorphic Caryopses, The Higher Is The Percentage Of Young Seedlings That Revive From Periods Of Desiccation. The Physiological And Ecological Implications Of L. Racemosus Seedling Desiccation Tolerance Are That Under Extreme Desert And Unpredictable Environmental Conditions, The Chances Of Seedling Establishment Are Increased.

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.

Seed germination at different temperatures and seedling emergence at different depths of Rhamnus spp

2014 ◽  
Vol 9 (5) ◽  
pp. 569-578 ◽  
Author(s):  
Hanan Aou-ouad ◽  
Hipólito Medrano ◽  
Ahmed Lamarti ◽  
Javier Gulías
Keyword(s):  
Seed Germination ◽  
Seedling Recruitment ◽  
Seedling Emergence ◽  
Burial Depth ◽  
Temperature Regimes ◽  
Mediterranean Shrubs ◽  
Different Temperatures ◽  
Temperature Ranges ◽  
Different Depths ◽  
Rhamnus Alaternus

AbstractRhamnus alaternus and R. ludovici-salvatoris, two Mediterranean shrubs with different geographic distributions, have shown important differences in seedling recruitment capacity. The objectives of this work were to determine the ability of these species to germinate seeds under different temperature ranges, as well as the capacity of seedlings to emerge from different burial depths, in order to better understand their regeneration processes. Two different experiments were performed. In the first one, seed germination was studied in Petri dishes and in the dark at different temperature regimes: a) 5–15°C, b) 10–20°C and c) 15–25°C (12h/12h). In the second experiment, seedling emergence capacity from different burial depths (0.5, 2 and 5 cm) was tested. R. ludovici-salvatoris showed a significantly higher final germination rates, a lower dormancy period, and average time response at 10–20°C than at other temperature ranges, although differences were much greater when seeds were subjected to the 5–15°C temperature regime. By contrast, R. alaternus did not show significant differences between treatments (5–15°C and 10–20°C) in germination behavior. Seedling emergence of both species was lower and slower when seeds were buried at 5 cm. However, R. ludovici-salvatoris always showed a lower seedling emergence capacity than R. alaternus at any burial depth. The low ability of R. ludovici-salvatoris to germinate seeds and emerge between 5–15°C, even from shallow depths, is discussed in relation to its low regeneration capacity and declining geographic distribution.

Effects of burial of seeds and seedlings from different seed sizes on the emergence and growth of Strophostyles helvola

1996 ◽  
Vol 74 (8) ◽  
pp. 1322-1330 ◽  
Author(s):  
Mary Yanful ◽  
M. A. Maun
Keyword(s):  
Lake Erie ◽  
Sandy Beach ◽  
Seedling Emergence ◽  
Seed Mass ◽  
Large Mass ◽  
Burial Depth ◽  
Different Depths ◽  
Mass Burial ◽  
Provincial Park

Field and greenhouse studies were conducted to examine the role of seed mass in (i) the emergence of seedlings of Strophostyles helvola (L.) Ell. from different depths of burial in sand and (ii) the ability of seedlings originating from seeds of different seed mass (weight per seed) to re-emerge from sand deposits. Seeds were sorted into four different seed mass classes (small, < 55 mg; medium, 55–65 mg; large, 65–75 mg; and extra large, > 75 mg) and sown at different depths ranging from 2 to 24 cm in sand on a sandy beach at Port Burwell Provincial Park along Lake Erie. Seeds of large mass class (65–75 mg) sown at 18 cm depth produced the largest plants. Under greenhouse conditions, all S. helvola seedlings buried to 100 and 125% of their height survived the treatment, but survival declined to 66% when they were buried to 150% of their height. Stimulation in growth was observed only when the seedlings were buried to 50 and 75% of their height. Seedlings originating from large seed masses took fewer days to re-emerge from different burial depths than seedlings from small seeds. However, the interaction term between seed mass and burial depth for the re-emergence of seedlings was not significant. Keywords: seed mass, burial of seeds, burial of seedlings, Strophostyles helvola, seedling emergence.

scholarly journals GIBBERELLIC ACID DURING PRIMING OF PURPLE CONEFLOWER [ECHINACEA PURPUREA (L) MOENCH.] SEEDS IMPROVES GERMINATION AND SEEDLING EMERGENCE

HortScience ◽  
1995 ◽  
Vol 30 (2) ◽  
pp. 186c-186
Author(s):  
Janine O. Haynes ◽  
Wallace G. Pill
Keyword(s):  
Gibberellic Acid ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Echinacea Purpurea ◽  
Germination Percentage ◽  
Shoot Dry Weight ◽  
Greenhouse Study ◽  
Purple Coneflower ◽  
Percentage Points

Purple coneflower seeds following priming (-0.04 MPa, 10 days, 15C, darkness) osmotically in polyethylene glycol 8000 (PEG) or matrically in expanded no. 5 vermiculite had greater germination rate and synchrony at continuous 20C or 30C than untreated seeds, but germination percentage was unaffected. Inclusion of 5.5 × 10-2 M gibberellic acid (GA3 as ProGibb Plus 2X, Abbott Laboratories, N. Chicago, Ill.) further improved germination rate and synchrony at 20C, but not at 30C. In a greenhouse study (30C day/27C night, July-August natural light), seeds primed in PEG or vermiculite containing G A3 compared to untreated seeds had 6 percentage points higher maximum emergence (ME), 3.3 fewer days to 50% ME, 1.9 fewer days between 10% and 90% ME, 116% greater shoot dry weight, and 125% longer leaves at 16 days after planting in peat-lite. Inclusion of ethephon (0.01 m, as Florel) either alone or with GA3 during priming provided no benefit to seed germination or seedling emergence. Moistened vermiculite substituted for PEG solution as a priming medium for purple coneflower seeds, the priming benefit on seedling emergence and growth being enhanced by 5.5 × 10-2m G A3 inclusion in the priming media.

scholarly journals Inhibitory impact of Daraikh (Melia Azedarach) leaves litter on wheat (Triticum aestivum) seedling

2021 ◽  
Vol 27 (2) ◽  
pp. 191-200
Author(s):  
Iqtidar Hussain
Keyword(s):  
Triticum Aestivum ◽  
Negative Impact ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Inhibitory Effect ◽  
Germination Percentage ◽  
Melia Azedarach ◽  
Growth Stages ◽  
Initial Growth ◽  
Coleoptile Length

A biological phenomenon by which one plant releases some chemicals in the environment that affect the rate of germination, its seedling emergence and physiology and overall growth of neighboring plants is called allelopathy. The significance of study was checked allelopathic phytochemical potential of Daraikh (Melia Azedarach L.) leaves on Wheat. Leaves litter were used to examine the allelopathic effects of Daraikh (Melia Azedarach) at five concentrations (100, 200, 300, 400 g, control) parameters studied germination percentage (%), Speed of germination, plant height (cm), root length (cm), Shoot length (cm), coleoptile length (cm), Fresh weight (g) and dry weight (g), Tiller (plant-1) and chlorophyll content (µ cm-2) of Triticum aestivum. All concentration of Leaves litter of Melia Azedarach showed pronounced inhibitory effect on all parameters of Triticum aestivum. Melia Azedarach exerted phytotoxic influence on Triticum aestivum at initial growth stages. Melia Azedarach exhibited a significant negative impact on germination of Triticum aestivum at 100, 200, 300, 400 g litter of leaves than control (Sterilized soil) repectively. Melia Azedarach halted the coleoptile length of Triticum aestivum @ 400 g leaves litter. Powdered leaves of Melia Azedarach in clay loam soil appeared to have strong allelopathic inhibition under maximum concentrations on growth and germination of Triticum aestivum. Hence, Melia Azedarach proved a strong allelopathic plant that should be planted aside from field to avoid harmful impacts during early growth stages of Triticum aestivum.

scholarly journals Germination and Emergence of Parsley in Response to Osmotic or Matric Seed Priming and Treatment with Gibberellin

HortScience ◽  
2000 ◽  
Vol 35 (5) ◽  
pp. 907-909 ◽  
Author(s):  
Wallace G. Pill ◽  
Elizabeth A. Kilian
Keyword(s):  
Polyethylene Glycol ◽  
Gibberellic Acid ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Seed Priming ◽  
Germination Percentage ◽  
Petroselinum Crispum ◽  
Hypocotyl Length ◽  
Shoot Dry Weight ◽  
Emergence Percentage

`Moss Curled' seeds of parsley (Petroselinum crispum L.) were primed osmotically in polyethylene glycol or matrically in fine, exfoliated vermiculite at –0.5 MPa for 4 or 7 days at 20 or 30 °C with 0 or 1 mm GA3. All priming treatments stimulated and hastened germination. Matric priming resulted in greater germination (89%) than osmotic priming (83%) when seeds were primed for 7 days at 30 °C, but priming agent had no effect on germination percentage following priming at 20 °C or for 4 days. In seeds primed for 4 days at 20 or 30 °C, matric priming hastened germination more than did osmotic priming. Germination was generally less synchronous with matric than with osmotic priming. Increasing priming time from 4 to 7 days increased the rate of germination, but increased germination synchrony only when seeds were primed at 20 °C. Inclusion of 1 mm GA3 during priming had little or no effect on germination. All matric priming treatments (other than 4-day priming) were repeated to assess seedling emergence in a greenhouse (25°C day/22 °C night). Priming increased the percentage, rate and synchrony of emergence, and increased hypocotyl length at 3 weeks after planting. Priming at 30 °C with 1 mm GA3 resulted in the greatest emergence percentage, hypocotyl length, and shoot dry weight. We conclude that matric priming is a satisfactory alternative to osmotic priming of parsley seeds. Chemical name used: gibberellic acid (GA3).

scholarly journals The Effect of Halo- and Hydro-Priming on Germination Characteristics of Millet Seeds Under Salinity Stress

2014 ◽  
Vol 47 (2) ◽  
pp. 41-48 ◽  
Author(s):  
M.A. Aghbolaghi ◽  
M. Sedghi
Keyword(s):  
Salinity Stress ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Seed Priming ◽  
Germination Percentage ◽  
Utilization Efficiency ◽  
Seedling Length ◽  
Germination Characteristics ◽  
Normal Seedling ◽  
Four Levels

Abstract Low seed germination and seedling emergence is one of the main problems in saline areas. Seed priming technique has been known as a challenge to improve germination and seedling emergence under different environmental stresses. The objective of this research was to evaluate the effect of seed priming with NaCl and water on growth and seed reserve utilization of millet seeds under salinity stress. Treatments were combinations of four levels of salinity stress (0, ⊟4, ⊟8 and ⊟12 bar) and three levels of seed priming and control with three replicates. Results showed that with increase in salinity stress, germination components such as germination percentage, germination index, mean time to germination, normal seedling percentage, seedling length, seedling dry weight of utilized (mobilized) seed and seed reserve utilization efficiency decreased, but seed priming showed lower reduction. The highest germination characteristics and seed reserve utilization was obtained by halo-priming in control conditions. It is concluded that priming results in improvement in germination components of millet in salinity stress conditions.

Effects of sand burial on seed germination, seedling emergence, survival, and growth of Agropyron psammophilum

1990 ◽  
Vol 68 (2) ◽  
pp. 304-310 ◽  
Author(s):  
Jianhua Zhang ◽  
M. A. Maun
Keyword(s):  
Seed Germination ◽  
Negative Correlation ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Burial Depth ◽  
Sand Burial ◽  
Buried Seeds ◽  
Percent Germination ◽  
Survival And Growth ◽  
The Mean

Studies were conducted to determine the effects of sand burial on seed germination, seedling emergence, survival, and growth of Agropyron psammophilum. In the field, seedlings of A. psammophilum emerged from burial depths ranging from 0 to 7 cm. The mean depth of seedling emergence was 2.96 ± 1.06 (mean ± SD) cm, with more than 80% individuals emerging from 0 to 4 cm depths of sand burial. In a greenhouse, seeds of A. psammophilum were artificially buried by sand to depths of 0, 2, 4, 8, 10, and 12 cm. Higher emergence percentages were obtained at 2 and 4 cm burial depths and no seedling emerged from depths greater than 8 cm. The percent germination of buried seeds, percent emergence, and emergence rte of seedlings showed negative correlation with burial depth. Burial of young seedlings up to a depth of 6 cm stimulated their growth in height, leaf and tiller production, and overall dry weight. When the burial depth exceeded 6 cm, some seedlings died and if seedlings were buried to 100% of their height (11 cm for 1-week-old and 22 cm for 2-week-old seedlings), all seedlings died.

Germination ecology of giant chickweed (Myosoton aquaticum)

Weed Science ◽  
2020 ◽  
Vol 68 (6) ◽  
pp. 619-626
Author(s):  
Hengzhi Wang ◽  
Lipeng Wang ◽  
Shuang Bai ◽  
Wenlei Guo ◽  
Jinxin Wang ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Seedling Emergence ◽  
Management Strategies ◽  
Germination Percentage ◽  
Burial Depth ◽  
Limited Information ◽  
Weed Species ◽  
Wide Ph Range ◽  
Ph Range ◽  
Deep Plowing

AbstractGiant chickweed [Myosoton aquaticum (L.) Moench], a troublesome broadleaf weed species, is widespread in winter wheat (Triticum aestivum L.) fields in China. However, limited information is available on its germination and seedling emergence ecology. Thus, three M. aquaticum populations (JS, HN, and AH) from different geographic regions were studied under laboratory conditions to determine the effects of different environmental factors on germination or seedling emergence. The seeds germinated at a relatively wide constant temperature range of 5 to 25 C; however, the optimal temperature for germination varied among the populations. Compared with constant temperatures, fluctuating temperatures with the same mean significantly improved the final germination of all populations. Light was not required for germination. The seeds germinated under a wide pH range of 3 to 10, and the optimum pH was 6 to 7, with a final germination percentage of 81% to 95%. The seeds of all populations showed similar sensitivities to osmotic potential and similar high tolerances of saline conditions. The seedling emergence of all populations decreased with increasing burial depth, and no emergence was observed when the seeds were buried more than 3 cm, but the AH population showed higher sensitivity to burial depth than the others. The results generated from this study will contribute to the development of integrated M. aquaticum management strategies for winter wheat fields in China, and deep plowing and late sowing of autumn-sown wheat are suggested for managing M. aquaticum, as it showed lower germination at a low temperature and under relatively deep burial.

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