Seed germination and emergence of two flax-leaf alyssum (Alyssum linifolium Steph. ex. Willd.) populations in response to environmental factors

2019 ◽  
Vol 70 (9) ◽  
pp. 807
Author(s):  
A. Mobli ◽  
S. Mijani ◽  
A. Ghanbari ◽  
M. Rastgoo
Keyword(s):  
Seedling Emergence ◽  
Germination Percentage ◽  
Climatic Conditions ◽  
Weed Species ◽  
Experimental Conditions ◽  
Temperature Regimes ◽  
Wide Range ◽  
Ph Range ◽  
East Azerbaijan ◽  
Two Populations

Flax-leaf alyssum (Alyssum linifolium Steph. ex. Willd.) is a winter growing annual weed species widely distributed in many semi-arid cropping regions of Iran, especially in the Khorasan Razavi and East Azerbaijan provinces. The germination of two populations (one each from Khorasan Razavi and East Azerbaijan) of this weed was evaluated under different experimental conditions. Seeds of A. linifolium germinated over a wide range of day/night temperature regimes, with the highest germination percentage observed with a regimen of 20°C/10°C. Light was not required for germination for either population, and >70% seeds germinated under all photoperiods tested. Germination was affected by pH levels; seeds germinated over the pH range 4–9 and germination was maximum at pH 7. For the Khorasan Razavi and East Azerbaijan populations, ≥50% of seeds germinated at a water potential of –0.69 and –0.78 MPa and salinity of 12.64 and 11.7 dS m–1 respectively. Maximum seedling emergence occurred when seeds were slightly covered with soil, but emergence decreased with increasing depth of soil cover, with no emergence at depths >3 cm. These results indicate that A. linifolium germinates in a wide range of climatic conditions and could invade into new regions. Burying the seeds through tillage may reduce their emergence.

Environmental factors affect seed germination and seedling emergence of invasive Centaurea balsamita

2017 ◽  
Vol 68 (6) ◽  
pp. 583 ◽  
Author(s):  
Iraj Nosratti ◽  
Samira Soltanabadi ◽  
Saeid J. Honarmand ◽  
Bhagirath S. Chauhan
Keyword(s):  
Seed Germination ◽  
Environmental Factors ◽  
Osmotic Potential ◽  
Seedling Emergence ◽  
Potassium Nitrate ◽  
Weed Species ◽  
Invasive Weed ◽  
Western Iran ◽  
Temperature Regimes ◽  
Wide Range

Centaurea balsamita is a problematic and invasive weed of agricultural fields in western Iran. This study was conducted to determine the effect of different environmental factors on germination and seedling emergence of this weed species. Results revealed that seed germination occurred over a wide range of temperatures (from 5°C to 35°C) with the highest germination at 25°C. Seed germination of C. balsamita was similar between light and dark conditions. Germination decreased with increased in water stress levels, but some seeds were capable of germinating at –1.4 MPa osmotic potential. Seed germination was sensitive to salt stress and complete inhibition occurred at 150 mM sodium chloride. Seed germination of C. balsamita occurred over a pH range of 4–10 with lowest seed germination at pH 4. Seed germination was inhibited by increasing concentrations of potassium nitrate. No seedlings emerged when seeds were buried in the soil at depths greater than 6 cm, suggesting that using a sweep cultivator in crops and deep tillage would be beneficial in managing C. balsamita. The ability of C. balsamita to germinate under a wide range of temperature regimes and high levels of osmotic potential shows that this weed is well adapted to invade other cropping regions, especially rain-fed fields in western Iran.

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.

Influence of temperature on the hatch of Heterodera avenae Woll. populations from Algeria

Nematology ◽  
2001 ◽  
Vol 3 (2) ◽  
pp. 171-178 ◽  
Author(s):  
Aïssa Mokabli ◽  
Jean-Pierre Gauthier ◽  
Roger Rivoal ◽  
Sylvie Valette
Keyword(s):  
Coastal Plain ◽  
Climatic Conditions ◽  
Heterodera Avenae ◽  
Seasonal Temperature ◽  
Wide Range ◽  
Influence Of Temperature On ◽  
Higher Temperature ◽  
The Times ◽  
Response To Temperature ◽  
Two Populations

AbstractTwo Algerian populations of Heterodera avenae originating from Oued Smar in a sub-humid coastal plain and from Tiaret in an inland semi-arid plain were subjected to different temperature treatments and juvenile emergence evaluated. These populations were compared with two populations, Fr1 and Fr4 from southern and northen France, respectively, which represent two ecotypes with respect to hatching cycles in response to temperature. The two Algerian populations hatched over a wide range of constant temperatures (3 to 25°C) but differed in the times at which juveniles emerged from the cysts. Simulation of seasonal temperature variations (from summer to autumn or winter and, conversely, from winter to spring or summer) demonstrated diapause in these two populations, induced by higher temperature (20 and 25°C) treatments and broken subsequently by lower temperatures (3 and 7°C). Both Algerian populations of H. avenae represent the Mediterranean ecotype, with biological variations that may represent regional adaptations to more or less severe climatic conditions.

EFFECT OF REDUCING AGENTS ON THE VIABILITY OF EQUINE ENCEPHALOMYELITIS VIRUS (EASTERN TYPE)

1946 ◽  
Vol 24e (4) ◽  
pp. 119-133
Author(s):  
N. A. Labzoffsky
Keyword(s):  
Sodium Chloride ◽  
Reducing Agents ◽  
Present Communication ◽  
Virus Suspension ◽  
Experimental Conditions ◽  
Cysteine Hydrochloride ◽  
Wide Range ◽  
Encephalomyelitis Virus ◽  
Ph Range

The present communication deals with the effect of reducing agents (cysteine hydrochloride, sodium thioglycollate, and sodium formaldehyde sulphoxylate) on the viability of equine encephalomyelitis virus (Eastern type). Cysteine hydrochloride was found to be a valuable reagent in in vitro studies of equine encephalomyelitis virus, because it greatly retards loss of infectivity of the virus under experimental conditions. It was observed that a virus suspension containing cysteine hydrochloride (1:1000) remained infective after exposure to 37 °C. for 14 days, although the guinea-pig titre was reduced from 1:108 to 1:102. The same reduction in the titre of virus suspended in buffered 0.85% sodium chloride solution occurred after exposure to 37 °C. for 120 hr. only, and in unbuffered 0.85% sodium chloride after 24 hr. exposure. Further, equine encephalomyelitis virus, in the presence of cysteine hydrochloride, retains its infectivity without demonstrable loss, over a pH range between 4.8 and 8.2 for 48 hr. at 37 °C. The titre of equine encephalomyelitis virus is maintained at 37 °C. for 48 hr. in a rather wide range of Eh, created with the aid of cysteine hydrochloride, at least in the range between − 0.151 and + 0.02 volts. On the other hand, addition of sodium formaldehyde sulphoxylate or sodium thioglycollate to a suspension of equine encephalomyelitis virus does not retard loss of infectivity of the virus. These reagents, therefore, are not suitable for the conservation of infectivity of the virus in vitro.

Environmental Factors Affecting Seed Germination and Seedling Emergence of Foxtail Sophora (Sophora alopecuroides)

Weed Science ◽  
2017 ◽  
Vol 66 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Iraj Nosratti ◽  
Sahar Amiri ◽  
Alireza Bagheri ◽  
Bhagirath Singh Chauhan
Keyword(s):  
Seed Germination ◽  
Seedling Emergence ◽  
Farming Systems ◽  
Substantial Effect ◽  
Weed Species ◽  
Factors Affecting ◽  
Sophora Alopecuroides ◽  
Dryland Farming ◽  
No Till ◽  
Temperature Regimes

Foxtail sophora is a widely distributed problematic weed in western Iranian dryland farming systems. Little information is available on seed germination and seedling emergence of this weed species in response to environmental and agronomic factors. This study was conducted to address this knowledge gap. Maximum seed germination (80%) occurred at 25 C and decreased at lower temperatures (<1% at 5 C) or under fluctuating temperature regimes. Light and pH did not have any substantial effect on seed germination. Foxtail sophora was tolerant to osmotic stress and moderately tolerant to sodium chloride. It was tolerant to salinity and drought stress during germination, which suggests that the population of this weed may increase in western farmlands of Iran. No seedlings emerged when seeds were buried at depths greater than 6 cm, which indicates that minimum- and no-till systems would increase seedling emergence of this species. Therefore, using sweep cultivators would be beneficial in management of foxtail sophora seedlings in the drylands of west of Iran.

scholarly journals The Influence of Environmental Factors on Seed Germination of Polygonum perfoliatum L.: Implications for Management

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1123
Author(s):  
Shahid Farooq ◽  
Huseyin Onen ◽  
Sonnur Tad ◽  
Cumali Ozaslan ◽  
Samy F. Mahmoud ◽  
...  
Keyword(s):  
Seed Germination ◽  
Osmotic Potential ◽  
Seedling Emergence ◽  
Management Strategies ◽  
The Black Sea ◽  
Burial Depth ◽  
Weed Species ◽  
Black Sea Region ◽  
Wide Range ◽  
Polygonum Perfoliatum

Polygonum perfoliatum L. is an aggressive vine, currently invading the Black Sea region, Turkey. However, information about the seed germination biology of this species is scanty. The objective of the current study was to determine the seed germination biology of three naturalized populations of this species. Chemical scarification with 98% sulfuric acid for 30 min followed by cold-wet stratification at 4 °C for 4 weeks effectively released seed dormancy in tested populations. Seeds of all populations required a 12 h photoperiod for the highest germination, while germination under continuous dark and light remained similar. The seeds were able to germinate under a wide range of constant (5–40 °C) and alternating temperatures, pH (3–11), osmotic potential (0 to −1.4 MPa) and salinity (0–500 mM NaCl). However, the peak germination was observed under 20 °C constant and 20/15 °C alternating day/night temperature, and pH 6.8. Seeds of all populations were able to withstand 200 mM salinity and −0.6 MPa osmotic potential. Increasing seed burial depth initially stimulated seedling emergence and then a sharp decline was observed for the seeds buried below >2 cm depth. More than 90% of the seeds were unable to emerge when buried >6 cm depth. Polygonum perfoliatum has a large potential for range expansion; therefore, immediate management of the naturalized populations is warranted. This weed species in agricultural fields can be managed by burying the seeds in deeper soil layers (6 cm), while post-emergence management strategies need to be developed for roadside populations.

Germination biology of dimorphic seeds of the annual halophyte common seepweed (Suaeda glauca)

Weed Science ◽  
2019 ◽  
Vol 68 (2) ◽  
pp. 143-150
Author(s):  
Hongfei Wang ◽  
Lin Kong ◽  
Rui Gao ◽  
Buhailiqiemu Abudureheman ◽  
Xinyang Li ◽  
...  
Keyword(s):  
Seed Germination ◽  
Salt Concentration ◽  
Seedling Emergence ◽  
Germination Percentage ◽  
Common Salt ◽  
Light Conditions ◽  
Effective Measure ◽  
Temperature Regimes ◽  
Suaeda Glauca ◽  
Black Seeds

AbstractCommon seepweed [Suaeda glauca (Bunge) Bunge] is a common salt-tolerant weed species distributed across the agricultural regions of northern China. It produces dimorphic seeds with different phenotypic characteristics and seed sizes. However, there is no information regarding the germination biology of these dimorphic seeds. Studies were conducted to evaluate the effects of ecological factors such as temperature, light, pH, osmotic stress, salt concentration, and planting depth on seed germination and seedling emergence. The results showed that brown seeds were nondormant, whereas black seeds had an intermediate physiological dormancy. The germination percentage of brown seeds was more than 80% at all temperature regimes and light conditions, but the optimum germination occurred at the cold thermoperiod of 20/10 C. In contrast, less than 6% of black seeds germinated at all temperature regimes and light conditions. Eight weeks of cold stratification did not break the dormancy of black seeds, whereas low concentrations of gibberellic acid (0.1 and 1.0 mM) significantly increased seed germination. Removal of the testa of black seeds also promoted germination and produced normal seedlings. Brown seeds showed moderate tolerance to salt stress, with 16% germination percentage at a salt concentration of 600 mM NaCl. The germination of brown seeds was 38% at an osmotic potential stress of −0.8 MPa; above that, no germination was obtained. Brown seeds germinated well in a wide pH range (4 to 10), with a germination percentage higher than 95%. Seedling emergence percentage was higher than 90% at burial depths of 0 to 2 cm, while germination percentage severely decreased for brown seeds with burial depths >2 cm, indicating that shallow tillage could be an effective measure to minimize seed germination. Information gathered from this study will help to develop an effective protocols for controlling S. glauca.

scholarly journals Solution pH and Papaya Seed Germination and Seedling Emergence

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 486E-486
Author(s):  
Robin A. DeMeo ◽  
Thomas E. Marler
Keyword(s):  
Seed Germination ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Germination Percentage ◽  
Growth Chamber ◽  
Sand Culture ◽  
Solution Ph ◽  
Wide Range ◽  
Substrate Ph ◽  
Papaya Seed

Two studies were conducted to determine the influence of pH on papaya seed germination and seedling emergence. The germination test was conducted with `Waimanalo' and `Tainung 1' seeds, using a double layer of filter paper disks in plastic petri dishes placed within a growth chamber. Each dish received 40 seeds, and germination was defined as when the radicle was visible. Disks were wetted daily with nutrient solution adjusted to pH of 3, 4, 5, 6, 7, 8, or 9. Germination began on day 5, and the study was terminated on day 23. Solution pH did not influence germination rate or ultimate germination percentage. `Waimanalo' exhibited 58% germination and `Tainung 1' exhibited 64% germination in this test. The seedling emergence study was conducted with `Waimanalo' seeds using sand culture within a growth chamber. Thirty seeds were planted in 10-cm containers, and the sand was irrigated daily with the solutions from the first study. Emergence was defined as when the hypocotyl hook was visible above the sand. Emergence began on day 10, and the study was terminated on day 30. Solution pH did not influence seedling emergence, and mean emergence was 69% in this study. The results indicate that the seed germination and seedling emergence stages of papaya seedling growth are adapted to a wide range of substrate pH.

Cobalt(II), nickel(II), and copper(II) complexes of di- and tetrapeptides containing tyrosine and glycine residues

1979 ◽  
Vol 57 (1) ◽  
pp. 104-112 ◽  
Author(s):  
Mohamed S. El- Ezaby ◽  
Jassim M. Al-Hassan ◽  
Namek F. Eweiss ◽  
Farida Al-Massaad
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Mixed Solvent ◽  
Equilibrium Constants ◽  
Carboxyl Groups ◽  
Experimental Conditions ◽  
Ph Titration ◽  
Solution Equilibria ◽  
Wide Range ◽  
Ph Range

The solution equilibria of di- and tetrapeptides containing tyrosine and glycine residues have been investigated in absence and presence of cobalt(II), nickel(II), and copper(II) ions. The equilibrium constants have been determined by pH titration at 30 °C and μ = 0.1 M(NaNO3) in 80% by weight DMSO – water mixed solvent. Protons are ionized from terminal (protonated amino and carboxyl) groups as well as from peptidic nitrogens. Complexes of 1:1 composition of metal ion – tetrapeptides were formed in quite a wide range of pH; also 1:1 complexes of the metal ions – dipeptides were formed in solution under the same conditions. Other higher complexes cannot be proved to form in the pH range studied. The complexes of these metal ions with glycine and O-Bzl-L-tyrosine were also studied under the same experimental conditions as control experiments and their equilibrium constants were calculated.

scholarly journals Influence of Organic Amendment and Inorganic Sources in relation to Crop Yield of Ragi and Soil Characteristics

2004 ◽  
Vol 3 (1) ◽  
pp. 11-19
Author(s):  
Gopal Dasar ◽  
G. N. Gajanana ◽  
B. Basavaraj
Keyword(s):  
Agricultural Soils ◽  
Seedling Emergence ◽  
Climatic Conditions ◽  
Lower Amount ◽  
Soil Crust ◽  
Run Off ◽  
Wide Range ◽  
Loam Soil ◽  
Rain Drops ◽  
Dispersion Ratio

A fields experiment was conducted on a sandy clay loam soil during summer season to characterize the soil crust to alleviate soil crust with organic waste and other amendments to improve the yield. Maize residue treatment recorded significantly higher grain and straw yields, seedling emergence, reduction in the crust strength and increase in the moisture content of the crust was observed due to maize residues incorporation. Soil crust contains higher amount of finer fractions, sesquioxides, iron, dispersion ratio and lower amount of organic matter. The problem of soils crusting is common in agricultural soils under a wide range of climatic conditions. Soil crust is a hard layer formed on the surface due to impact of rain drops and subsequent drying. Though the seeds germinate below the crust, seedlings are not able to exert sufficient upward pressure to pierce through the crust resulting in pre-emergence death of seedlings, crusts are known to adversely affect seedling emergence, early growth of seedling oxygen supply, moisture iniliteration but increase erosion and run off.

Sign in / Sign up

Export Citation Format

Share Document