scholarly journals Factors Affecting Seed Dormancy and Germination of Greater Bur-Parsley (Turgenia latifolia)

2018 ◽  
Vol 36 ◽  
Author(s):  
M. REZVANI ◽  
S.A. SADATIAN ◽  
H. NIKKHAHKOUCHAKSARAEI

ABSTRACT: Our knowledge about seed dormancy breaking and environmental factors affecting seed germination of greater bur-parsley (Turgenia latifolia) is restricted. This study has addressed some seed dormancy breaking techniques, including different concentrations of gibberellic acid (GA3) and potassium nitrate (KNO3), leaching duration, physical scarification as well as some environmental factors effective on seed germination such as salt and drought stresses, pH and seed planting depth. Seed germination was promoted with lower concentrations of KNO3 (0.01 to 0.02 g L-1), while higher concentrations reduced germination percentage. Seed dormancy was declined by low concentrations of GA3 up to 100 ppm. Seeds of greater bur-parsley germinated in a range of pH from 3 to 7. With enhancement of drought and salt stresses, seed germination decreased. Also, there was no seed germination in a high level of stresses. Seedling emergence reduced as planting depth increased. Use of GA3, KNO3, leaching and physical scarification had a positive effect on seed dormancy breaking of greater bur-parsley. The information from the study increases our knowledge about seed dormancy breaking techniques, response of germination to drought and salt stresses and also determination of distribution regions of greater bur-parsley in the future.

Weed Science ◽  
2020 ◽  
pp. 1-29
Author(s):  
Yonghuan Yue ◽  
Guili Jin ◽  
Weihua Lu ◽  
Ke Gong ◽  
Wanqiang Han ◽  
...  

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.


Weed Science ◽  
1984 ◽  
Vol 32 (6) ◽  
pp. 781-785 ◽  
Author(s):  
Megh Singh ◽  
Nagi Reddy Achhireddy

The germination of milkweedvine (Morrenia odorataLindl. ♯3MONOD) seed at 20 or 25 C was unaffected by a 12-h photoperiod. The 12-h photoperiod, however, decreased germination by 50% at 15 C. No germination occurred at 35 C regardless of photoperiod. By alternating 35 C for 12 h with 20 C for 12 h, the germination percentage was 57%. Seedling growth was maximum at alternating temperatures of 30/20 C. Optimum pH for germination and seedling growth was 7 and germination did not occur at pH levels below 6. Seed germination declined steadily at osmotic stress below −0.12 MPa; no germination occurred at −0.5 MPa. Seedling growth was not influenced by osmotic stress down to −0.18 MPa. Germination percentages of seeds kept under aerated water and nonaerated water were similar, but the seedling growth was greater in aerated water. Seedling emergence was maximum from depths of 0.5 to 2.5 cm, but no seedling emerged from 0 or 10 cm. Planting depth was negatively correlated (r = −0.7) with shoot growth but positively correlated (r = +0.98) to root growth.


2017 ◽  
Vol 68 (6) ◽  
pp. 583 ◽  
Author(s):  
Iraj Nosratti ◽  
Samira Soltanabadi ◽  
Saeid J. Honarmand ◽  
Bhagirath S. Chauhan

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.


2020 ◽  
Vol 144 (3-4) ◽  
pp. 159-166
Author(s):  
Hanife Erdogan Genç ◽  
Ali Ömer Üçler

This study was carried out to determine effects of different pretreatment on seed germination and to overcome dormancy in Acer cappadocicum seeds. The seeds were collected in 2008 three times with aproximately 15-days intervals. In order to overcome dormancy, several germination treatments were applied. The treatments were (1) different seed collection time, (2)soaking in water, (3) cold-moist stratification and (4) GA<sub>3</sub> (gibberellic acid) application. The treated seeds were germinated in growing chamber at 5 <sup>0</sup>C and in greenhouse conditions. This research showed that seeds of Acer cappadocicum exhibit physiological dormancy and require stratification period to overcome seed dormancy. The highest germination percentage in the growing chamber subjected to GA<sub>3</sub> process after eight weeks of stratification treatment was 62 % for Acer cappadocicum seeds. The highest germination percentage in greenhouse was obtained with cold stratification after eight weeks (95 %). It was found out that GA<sub>3</sub> treatment had a significant effect on germination in growth chamber + 5 <sup>0</sup>C but GA<sub>3</sub> treatment didn’t have a significant effect on germination in greenhouse conditions. GA<sub>3</sub> treatment and soaking of unstratified seeds in water for 48 hr didn’t have any positive effect on germination value in greenhouse conditions. Although growth chamber and green house results both indicated that seed collection time did not seem to play a role as statistically on seed germination, Duncan’s test showed that the third seed collection time was in a different group.


2021 ◽  
Vol 42 (3) ◽  
pp. 963-978
Author(s):  
Thaís Soares Pereira ◽  
◽  
Tatiane Sanches Jeromini ◽  
Breno Rosa Neves ◽  
Renato Téo de Barros ◽  
...  

The main difficulty with propagating Urochloa humidicola Comum is the high percentage of seed dormancy. Thus, the objective of this study was to develop a treatment to overcome seed dormancy and promote seed germination of this species that can be applied at a large scale. This study was conducted in two stages. First, the following treatments were evaluated using one seed lot: control (without treatment), immersion in H2SO4 (98%, 36N) for 10 min, moistening the germination substrate with KNO3 (0.2%) and immersion in KNO3 at concentrations of 0%, 2%, 4%, 6%, and 8% for periods of 12, 24, 36, and 48 h, followed by drying in the shade. In the second stage, three seed lots were evaluated in all of the aforementioned treatments, except for those of immersion in 0% KNO3 and of all concentrations for 36 and 48 h. The seeds were evaluated for water content, germination, percentage of abnormal seedlings, dead and dormant seeds, first count, and average germination time. Immersion in the KNO3 solution was efficient in overcoming dormancy and promoting germination. To be used by companies, the immersion of seeds in a 4% KNO3 solution for 24 h was the most suitable treatment to overcome dormancy and promote the germination of U. humidicola Comum seeds.


2014 ◽  
Vol 54 (2) ◽  
pp. 179-187 ◽  
Author(s):  
Hassan Karimmojeni ◽  
Alireza Taab ◽  
Behzad Rashidi ◽  
Amir Hossein Bazrafshan

Abstract In Iran, Descurainia sophia, Malcolmia africana, and Thlaspi arvense are abundantly found as importunate weeds in winter cereal. Understanding the timing of seed germination under natural conditions is crucial for learning how to manage these annual weeds. Therefore, this study was conducted to evaluate the effect of soil burial, dry storage, cold stratification, KNO3, GA3, and scarification on the seed dormancy and germination of these three species. Species had significantly different responses to the treatment. In D. sophia, seeds buried at a depth of 10 cm for 60 days (55%), and seeds dry stored at 20°C for 180 days (45%) showed the highest level of germination. In M. africana, the germination percentage reached 95% when seeds buried at a depth of 1 cm were soaked in a GA3 concentration of 150 ppm. T. arvense had the lowest level of germination compared to the other species. The highest percentage of T. arvense germination was obtained in seeds treated with 150 ppm GA3. Potassium nitrate partly increased germinability in seeds of M. africana, which initially were less dormant than those of T. arvense and D. sophia.


1992 ◽  
Vol 70 (5) ◽  
pp. 1012-1016 ◽  
Author(s):  
S. N. Acharya ◽  
C. B. Chu ◽  
R. Hermesh ◽  
G. B. Schaalje

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.


2013 ◽  
Vol 31 (4) ◽  
pp. 823-832 ◽  
Author(s):  
A. Derakhshan ◽  
J. Gherekhloo

Specific knowledge about the dormancy, germination, and emergence patterns of weed species aids the development of integrated management strategies. Laboratory studies were conducted to determine the effect of several environmental factors on seed germination and seedling emergence of Cyperus difformis. Germination of freshly harvested seeds was inhibited by darkness; however, when seeds were subsequently transferred to complete light they germinated readily. Our results showed that 2 wk of cold stratification overcome the light requirement for germination. Seeds of C. difformis were able to germinate over a broad range of temperatures (25/15, 30/20, 35/25, and 40/30 ºC day/night). The response of germination rate to temperature was described as a non-linear function. Based on model outputs, the base, the optimum and the ceiling temperatures were estimated as 14.81, 37.72 and 45 ºC, respectively. A temperature of 120 ºC for a 5 min was required to inhibit 50% of maximum germination. The osmotic potential and salinity required for 50% inhibition of maximum germination were -0.47 MPa and 135.57 mM, respectively. High percentage of seed germination (89%) was observed at pH=6 and decreased to 12% at alkaline medium (pH 9) pH. Seeds sown on the soil surface gave the greatest percentage of seedling emergence, and no seedlings emerged from seeds buried in soil at depths of 1 cm.


Botany ◽  
2021 ◽  
Author(s):  
Lanlan He ◽  
Ganesh K. Jaganathan ◽  
Baolin Liu

The timing of germination is a crucial event in a plant’s life cycle. Seed dormancy and germination mechanisms are important factors regulating seedling emergence. Since detailed experimental evidence for germination pattern of Phoenix canariensis colonizing sub-tropical climate is scarce, we investigated seed dormancy and germination ecology of P. canariensis. We found that the embryo is underdeveloped at the time of dispersal and doubles in size before the cotyledonary petiole (CP) protrudes through the operculum. The primary root and plumule emerge from the elongated CP outside the seed. In light/dark at 30/25°C, the CP emerged from 8% of the diaspores within 30 days and from 76% within 14 weeks. Thus, 8% of the diaspores have MD and the others MPD. Removal of the pericarp and operculum resulted in 100% germination within 5 days in light/dark at 30/25°C. Cold and warm stratification as well as treatment with GA3 significantly increased the germination speed, but the final germination percentage was not significantly increased. Seed germination was synchronized in early summer when seed dormancy was released by cold stratification in the soil over winter. A remote-tubular germination type and intricate root system provide an ecological advantage to the seedling establishment.


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