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

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.

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.


2014 ◽  
Vol 94 (4) ◽  
pp. 723-726
Author(s):  
D. J. Thompson

Thompson, D. J. 2014. Relating germination requirements of timber milkvetch to seral stage in the Interior Douglas-fir zone. Can. J. Plant Sci. 94: 723–726. Germination of timber milkvetch (Astragalus miser var. serotinus) seeds was studied to determine if it is an early or late seral species. Seeds were collected from a native plant population and those having a dark seed coat were selected. Germination tests were run in the light or dark and under three temperature regimes: low (constant 10°C), high (constant 25°C), and alternating (25°C day and 10°C night). Germination occurred over a protracted period with new germinants up to 90 d at the lowest temperature. Germination was not affected by light. Germination rate was greater at 25°C than 10°C, while fluctuating temperatures (25 and 10°C alternating every 12 h) reduced germination rate to that at the lower temperature. Days to 50% germination was a more sensitive indicator, with the mean for the fluctuating temperatures falling between those continuous to the high and low temperature. Final germination percentage was reduced at 10°C compared with 25°C, but not with fluctuating temperatures. Timber milkvetch seed germination did not respond to light or fluctuating temperatures, adding to a body of evidence that it is a late seral species.


2021 ◽  
Vol 11 (24) ◽  
pp. 11666
Author(s):  
Liaqat Ali ◽  
Wang Xiukang ◽  
Muhammad Naveed ◽  
Sobia Ashraf ◽  
Sajid Mahmood Nadeem ◽  
...  

Reduced germination and early crop maturity due to soil compaction, nutrients stress, and low moisture are major constraints to achieve optimum crop yield, ultimately resulting in significant economic damages and food shortages. Biochar, having the potential to improve physical and chemical properties of soil, can also improve nutrients and moisture access to plants. In the present study, a growth room experiment was conducted to assess biochar influence on maize seed germination, early growth of seedlings, and its physiological attributes. Corn cob biochar (CCB) was mixed with soil at different rates (0.5%, 1%, 1.5%, 2%, 2.5%, and 3% w/w) before seed sowing. Results obtained showed that increasing CCB application rate have neutral to positive effects on seed germination and seedling growth of maize. Biochar addition at the rate of 1.5% (w/w) significantly increased shoot dry biomass (40%), root dry biomass (32%), total chlorophyll content (a and b) (55%), germination percentage (13%), seedling vigor (85%), and relative water content (RWC) (68%), in comparison to un-amended control treatment. In addition to this, it also improved germination rate (GR) by 3% as compared to control treatment, while causing a reduction in mean emergence time (MET). Moreover, application of biochar (3%) also resulted in enhancement of antioxidant enzyme activity, particularly superoxide dismutase (SOD) and catalase (CAT) by 13% and 17%, respectively. Conclusively, biochar application is an attractive approach to improve the initial phase of plant growth and provide better crop stand and essential sustainable high yields.


2021 ◽  
pp. 76-82
Author(s):  
Getachew Shumye Adilu ◽  
Yohannes Gedamu Gebre

Salinity adversely affects 20-30% of the irrigated area in the world. Tomato is sensitive to salinity. It is one of the most severe abiotic factors of many agricultural crops and it becoming the main problem in Ethiopia. This study was conducted to evaluate the effects of different salinity levels on the seed germination parameters of tomato varieties. It was laid out in a completely randomized design with three replicates. The treatment included four tomato varieties (Sirinka, Weyno, ARP D2, and Roma VF) and five salinity levels (1 dS m-1, 2 dS m-1, 3 dS m-1, 4 dS m-1, and control). Fifty seeds were placed in a Petri dish over a moistened germination paper for germination and seedlings and allowed to grow for 14 days. The germination rate, speed and energy of tomato seeds were significantly (p < 0.001) affected by the combined effect of variety and salinity. The shortest mean germination time, the highest mean germination rate, and the highest speed of germination were recorded in the ARP D2 variety in the control treatment. The lowest first and last days of germination, and the uncertainty of germination were recorded from ARP D2. However, an increase in the days of germination and in the uncertainty of germination, and a decrease in the germination index and total germination percentage trends were observed with increasing salinity levels. The highest level of salinity (4 dS m-1) affected the germination of tomato varieties. Among the four tested tomato varieties, ARP D2 and Roma VF were tolerant to salinity.


2014 ◽  
Vol 6 (3) ◽  
pp. 282-287 ◽  
Author(s):  
Hamid-Reza FALLAHI ◽  
Arezoo PARAVAR ◽  
Mohammad-Ali BEHDANI ◽  
Mahsa AGHHAVANI-SHAJARI ◽  
Mohammad-Javad FALLAHI

Saffron intercropping with other plants needs to preliminary investigations about the possible negative interactions between saffron and associated crop. In this study, allelopathic effects of saffron leaf and corm extracts on germination and seedling growth indices of alfalfa (Medicago sativa), arugula (Eruca sativa) and rapeseed (Brassica napus) was investigated in six separate experiments based on completely randomized design. Experimental treatments were consisted of different levels of saffron leaf and corm extracts including 0, 0.75, 1.5, 3 and 6%. The maximum germination percentage of all selected crops was obtained at control treatment (on average 92%) and then decreased with increasing extracts concentration. So that, the germination percentage of arugula, canola and alfalfa in highest concentration of extracts were 18, 10 and 8% for leaf extract and 72, 68 and 93% for corm extract, respectively. The relatively similar trend was observed about germination rate, root and plumule lengths and dry weights. Therefore, the inhibitory effect of saffron leaf extract was more than corm extract on initial growth indices of studied plants. The lowest inhibitory effect of saffron leaf extract and even relatively high stimulatory effect of corm extract were obtained on alfalfa initial growth criteria. Considering the differences in allelochemicals mode of action and concentrations in laboratory bioassays with natural condition, it is necessary to investigate the effects of saffron residues on growth of selected associated crops in greenhouse and field scales for the final decision.


2021 ◽  
Vol 43 ◽  
Author(s):  
Nancy Araceli Godínez-Garrido ◽  
Juan Gabriel Ramírez-Pimentel ◽  
Jorge Covarrubias-Prieto ◽  
Francisco Cervantes-Ortiz ◽  
Artemio Pérez-López ◽  
...  

Abstract: Chitosan is a biopolymer obtained from deacetylation of chitin; it has multiple applications in agriculture as an antifungal, soil conditioner, inducer of defense mechanisms, fruits postharvest coating, leaves and seeds, among others. The objective in this research was to evaluate the effect of chitosan coatings mixed with fungicide (dithiocarbamate) on the germination and germination speed of bean and maize seeds in storage and to determine the retention capacity of the fungicide in the coated seeds under different times of imbibition. Two coating treatments at concentrations of 0.1 and 0.5% chitosan in water, two coatings treatments at 0.1 and 0.5% chitosan supplemented with 0.5% fungicide and a coating without chitosan using only 0.5% fungicide in water were used in bean and maize seed; and as control seeds imbibed in distilled water were used; after treatments, germination percentage and germination speed were determined, also fungicide release were determined at 0, 1, 2 and 6 h of imbibition, and the effect of storage time on germination and germination speed was determined at 30, 60, 90, 120, 150 and 180 days of storage at 4 °C and 45% relative humidity. The fungicide release effect was determined by inhibiting Fusarium oxysporum conidia germination. There were no negative effects of coatings on seed germination after storage. The treatment that provided both greater retention of the fungicidal agent and released it gradually, was 0.5% chitosan mixed with fungicide concentration. Chitosan coating seeds mixed with fungicide do not cause negative changes in seed germination or germination rate.


2021 ◽  
Vol 1 (01) ◽  
pp. 27-30
Author(s):  
IRANI KHATUN ◽  
RIYAD HOSSEN

Seed germination performance test of Taherpuri onion (a local variety of onion) under six different temperatures (15, 20, 25, 30, 35 and 40°C) was the main goal of this experiment. Germination percentage (GP) was calculated at highest 60.25% at 25°C, and the highest germination rate 20.08 was observed in the same temperature condition. The lowest germination performance (13.25 % germi-nation and 3.32 seeds per day as germination rate) was found at 40°C temperature. Finally, the authors mentioned the temperature 20 to 30°C as optimum range, and suggested the temperature 25°C as best suited for obtaining highest results in case of both germination percentage and germination rate of these seeds. To produce maximum seedlings of the local variety of onion, the mentioned temperature should be followed by the local farmers.


2010 ◽  
Vol 46 (2) ◽  
pp. 231-242 ◽  
Author(s):  
S. J. GOUSSOUS ◽  
N. H. SAMARAH ◽  
A. M. ALQUDAH ◽  
M. O. OTHMAN

SUMMARYA laboratory experiment was conducted to determine the effect of ultrasound (US) treatment on seed germination of chickpea, wheat, pepper and watermelon. All tests were carried out at 40 kHz in a water bath ultrasonic device varying two factors, treatment duration (5, 10, 15, 30, 45 or 60 min) and germination temperature (15 or 20 °C). Parallel tests were run in which seeds were soaked in water without sonication in order to eliminate the effect of water from US test results. The effects of US on seed germination varied between crops and were more obvious on germination speed, expressed as germination rate index (GRI), rather than on germination percentage (GP). In particular, US treatment significantly increased the GRI of chickpeas, wheat and watermelon, resulting in a maximum increase of 133% (at 45 min), 95% (30 min) and 45% (5 min), respectively, above control seeds. The beneficial effects of US on the GRI of these crops were observed at both 15 and 20 °C, suggesting that US treatment offers a practical priming method to overcome the slow germination that may occur at low temperatures. Water-soaking treatment improved the GP of both chickpea and pepper seeds by 59 and 24%, respectively, compared to the control but neither water nor US had any positive effect on pepper GRI. Post-treatment measurement of moisture content of these seeds produced variable results depending on crop species and US treatment duration. Results of this research indicated that US treatment effectively enhanced speed of germination of chickpea, wheat and watermelon seeds. This increase in speed of germination may improve early field establishment of these crops in the semiarid Mediterranean region and thus needs further investigation. The US technique may also be very useful for plant propagators in nurseries to achieve fast seedling establishment of watermelon.


Genetika ◽  
2012 ◽  
Vol 44 (2) ◽  
pp. 235-250 ◽  
Author(s):  
Ahmad Dadashpour

The effects of different salt sources (C Cl2, NaCl, and KCl) and concentrations, as measured by electrical conductivity, (0, "control", 1, 3, 5, 7 and 9 dS m-1) on seed germination and seedling growth of ?Ferro?, ?Obez?, ?RS 841? and ?Strong Tosa F1? pumpkin varieties used as rootstock were investigated in this study. The results showed that germination rate, root length, shoot length, fresh root weight, dry root weight, fresh shoot weight and dry shoot weights tend to decrease when the electrical conductivity of the solution is higher than 5 dS m-1, independent of salt sources and in all of the varieties. Three days after seeding, a germination ratio of 5 % was obtained from RS 841 variety in all salt source and concentrations, while a germination ratio over 50 % was obtained in ?Strong Tosa? variety for the same conditions except CaCl2 salt source. Nevertheless, seeds germinated in medium having high concentrations of CaCl2 had lower germination rate and poor seedling growth, compared to media having the same concentrations of NaCl and KCl. It was concluded that all of the varieties studied were more sensitive to the concentrations prepared using CaCl2 than that of the KCl, and NaCl.


2019 ◽  
Vol 52 (1) ◽  
pp. 26-33
Author(s):  
M. Khoshkharam ◽  
W. Sun ◽  
Q. Cheng ◽  
M.H. Shahrajabian

Abstract Allelopathy is the detrimental effect of one crop on germination or development of a plant of another species. A factorial layout within completely randomized design with four replications was used to survey the influence of barley extract on corn seeds. Treatments included plant organs extract (leaf, stem, root and total), and different barley extract densities (Nosrat cultivar) includes four levels of 0%, 25%, 50% and 100%. The influence of barley extract was significant on coleoptile weight, radicle weight, radicle length and coleoptile length. Plant organs had meaningful effect on germination rate, germination percentage, coleoptile weight, radicle weight, radicle length and coleoptile length. Among all experimental characteristics, coleoptiles length was influenced by interaction between barley extract and plant organ. Although, the highest germination rate and germination percentage was related to 25% and 100% of barley extract density, the maximum coleoptile weight, radicle weight, radicle length and coleoptiles length was related to control treatment (0%). Leaf extract has obtained the higher values of germination rate, germination percentage, coleoptile weight, radicle weight, radicle length and coleoptile length. Interaction between control treatment (0% plant extract) and stem extract had obtained the highest coleoptiles weight, radicle weight, radicle length and coleoptile length. Hence, from the obtained results, it can be concluded that the extracts of barley may have allelopathic influence on germination and seedling growth of corn.


Sign in / Sign up

Export Citation Format

Share Document