​Physiological, Biochemical and Molecular Mechanisms of Seed Priming: A Review

Author(s):  
A. Diya ◽  
R. Beena ◽  
V.G. Jayalekshmy

Legumes being a major source of protein have a wide range of economic importance. But the major constraints in growing legumes are poor germination, seedling emergence, non uniform stand establishment and crop mortality leading to lower pulse productivity. Thus, pre-sowing seed treatments are critical parameters which attribute to efficient plant growth and high yield. Uniform seed germination, seedling growth and uniform establishment are the critical stages during the growth of crops. Seed priming is a very promising presowing treatment employed to improve seed germination, better crop establishment, enhance the seed quality and induces tolerance against biotic and abiotic stresses in plants thereby providing a balanced healthy diet to the citizens. Priming is a cost effective and feasible strategy involving controlled hydration of seeds followed by drying to stimulate the pre-germinative metabolic activities to occur promoting rapid germination of seedlings, break dormancy and enhance crop yield. Enzymatic, metabolic and biochemical processes of the primed seeds attributes to rapid and uniform seedling emergence. Seed priming methods comprises of conventional methods including hydro priming, osmopriming, biopriming, chemical priming and the advanced methods including nano priming and priming with physical agents. In this review paper, the underlying physiological, biochemical and molecular aspects of priming in pulses were discussed.

Author(s):  
Bela Joshi ◽  
P. K. Rai ◽  
Vandana Pandey

Seed germination, following seedling growth are basic but crucial steps in a plant life cycle which includes proper seed germination which is a basic pre-requisite for a better crop growth and yield. The experiment was conducted in Vegetable Science Department under the Defence Institute of Bio-Energy and Research (DIBER), (DRDO), Pithoragarh, Uttarakhand in the year 2020-2021 to standardize the best treatment of seed priming specific to Spinach (Spinacia oleracea). An investigation was conducted both in a laboratory and on the field with the same treatment that was: (T1) Distilled water, (T2) 1%NaCl, (T3) 1%H2O2, (T4) 1%Na2CO3, (T5) Tap water, (T6) 1%DAP, (T7) Control. Seeds were soaked for 16 hrs and then dried to original moisture content for 2 days. It was found that all the priming treatments showed a significant difference with the control and the highest germination %(lab) with 71% was observed in seeds treated with DAP (T6) and the highest crop yield (field) were observed for 1% Na2CO3. Na2CO3 showed the best result in the field as well as in lab conditions based on different quality parameters followed by DAP. This study showed that seed priming treatments help in the enhancement of seed quality parameters, proved cost-effective and the most economical method. The experiment helps to improve the seed quality using different priming treatments which are cost-effective, economic, environment friendly and one of the quickest methods used for seed enhancement.


1998 ◽  
Vol 8 (4) ◽  
pp. 499-503 ◽  
Author(s):  
Daniel J. Cantliffe

Seed germination is a critical step to achieve economic success in a transplant operation. Total germination of a seed lot dictates total plant sales by the producer, while uniformity of germination dictates the quality of the transplant crop. Using high vigor seed will help to achieve uniform stands, as well as maximize stands, in the transplant house or field. In order to maintain the highest seed quality, transplant producers should store unused seeds at recommended temperature and relative humidity for the crop species. Methods to promote uniformity and optimum stands under a wide range of conditions include the use of seed priming, film coating with fungicides, and pelleting for ease of planting.


Author(s):  
Ashok S. Sajjan ◽  
M. S. Dhanelappagol ◽  
R. B. Jolli

Experiment was conducted in the Seed Testing Laboratory during 2013 and 2014 at RARS, UAS Campus, Vijayapur, Karnataka State. The seeds were primed by soaking in different leaf extracts and chemical solution for one hour and then decanted the extracts and seeds were air dried under the shade to bring back to their original moisture content and used for seed quality studies. Seed germination was significantly influenced by age of the seeds and its interaction with botanicals and chemicals. Among the treatments, botanicals viz., Prosopis leaf extracts @ 2per cent recorded higher seed germination followed by Pongamia leaf extract @ 2per cent. Whereas, in chemicals higher germination was seen in KNO3@ 0.5 per cent but at par with CaCl2 .2H2O @ 2 per cent. Lower seed germination was obtained with water soaked and control. The present investigation indicate that, seed priming with 2.0 per cent Prosopis leaf extract for one hours soaking enhanced the seed and seedling quality characters, and hence it could be adopted as a pre-sowing seed priming treatment in pigeon pea.


Weed Science ◽  
2017 ◽  
Vol 66 (1) ◽  
pp. 47-56 ◽  
Author(s):  
Ning Zhao ◽  
Qi Li ◽  
Wenlei Guo ◽  
Lele Zhang ◽  
Lu’an Ge ◽  
...  

Shortawn foxtail is an invasive grass weed infesting winter wheat and canola production in China. A better understanding of the germination ecology of shortawn foxtail would help to develop better control strategies for this weed. Experiments were conducted under laboratory conditions to evaluate the effects of various abiotic factors, including temperature, light, pH, osmotic stress, salt concentration, and planting depth, on seed germination and seedling emergence of shortawn foxtail. The results showed that the seed germination rate was greater than 90% over a wide range of constant (5 to 25C) and alternating (15/5 to 35/25C) temperatures. Maximum germination occurred at 20C or 25/15C, and no germination occurred at 35C. Light did not appear to have any effect on seed germination. Shortawn foxtail germination was 27% to 99% over a pH range of 4 to 10, and higher germination was obtained at alkaline pH values ranging from 7 to 10. Seed germination was sensitive to osmotic potential and completely inhibited at an osmotic potential of −0.6 MPa, but it was tolerant to salinity: germination even occurred at 200 mM NaCl (5%). Seedling emergence was highest (98%) when seeds were placed on the soil surface but declined with the increasing burial depth. No seedlings emerged when seeds were buried 6-cm deep. Deep tillage could be an effective measure to limit seed germination from increased burial depth. The results of this study will lead to a better understanding of the requirements for shortawn foxtail germination and emergence and will provide information that could contribute to its control.


Weed Science ◽  
2021 ◽  
pp. 1-27
Author(s):  
Aseemjot Singh ◽  
Gulshan Mahajan ◽  
Bhagirath Singh Chauhan

Abstract Wild mustard (Sinapis arvensis L.) is a widespread weed of the southeastern cropping region of Australia. Seed germination ecology of S. arvensis populations selected from different climatic regions may differ due to adaptative traits. Experiments were conducted to evaluate the effects of temperature, light, radiant heat, soil moisture, salt concentration, and burial depth on seed germination and seedling emergence of two [Queensland (Qld) population: tropical region; and Victoria (Vic) population: temperate region] populations of S. arvensis. Both populations germinated over a wide range of day/night (12 h/12 h) temperatures (15/5 to 35/25 C), and had the highest germination at 30/20 C. Under complete darkness, the Qld population (61%) had higher germination than the Vic population (21%); however, under the light/dark regime, both populations had similar germination (78 to 86%). At 100 C pretreatment for 5 min, the Qld population (44%) had higher germination than the Vic population (13%). Germination of both populations was nil when given pretreatment at 150 and 200 C. The Vic population was found tolerant to high osmotic and salt stress compared with the Qld population. At an osmotic potential of −0.4 MPa, germination of Qld and Vic populations was reduced by 85% and 42%, respectively, compared with their respective control. At 40, 80, and 160 mM sodium chloride, germination of the Qld population was lower than the Vic population. Averaged over the populations, seedling emergence was highest (52%) from a burial depth of 1 cm and was nil from 8 cm depth. Differential germination behaviors of both populations to temperature, light, radiant heat, water stress, and salt stress suggests that populations of S. arvensis may have undergone differential adaptation. Knowledge gained from this study will assist in developing suitable control measures for this weed species to reduce the soil seedbank.


Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1009
Author(s):  
Suresh Thangudu ◽  
Mu Tzu Lee ◽  
Sami Rtimi

Molybdenum Sulfide nanosheets (MoS2 NSs) have unique properties that allow its use in a wide range of applications. Unfortunately, a lack of green synthesis methods to achieve a high yield remains a challenge after decades. Herein we report a simple, ecofriendly, green and cost-effective approach to synthesize water soluble MoS2 NSs via probe/Tip sonication method. The sequential batch manner pathway allows us to attain a high yield of MoS2 NSs (~100%). The prepared MoS2 NSs were characterized using up-to-date surface science techniques. UV-visible-NIR spectroscopy allowed us to visualize the doublet peaks of pristine MoS2 at 610 and 680 nm concomitant with the inter-band transitions at 394 nm and 460 nm. Using Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS), the crystallites’ sizes were estimated. X-ray diffraction (XRD) and Raman Spectroscopy were performed with respect to the bulk MoS2. The energy difference between the Raman peaks revealed that our NSs are formed of 5–6 layers. Further, we explored enzyme peroxidase mimetic properties of the synthesized MoS2 NSs. Results showed that the present MoS2 NSs offer excellent peroxidase mimicking properties. Most importantly, we observed that the optical properties and characteristics of MoS2 NSs synthesized by the current green method are similar to those of MoS2 NSs synthesized using conventional harsh methods reported in the literature. So that we strongly assume that the present method is a green alternative for the existing low yield and harsh experimental procedures to achieve water soluble MoS2 NSs in high yield. The synthesized soluble NSs are promising catalysts for the detection of toxic chemicals in the environment and/or for following enzymatic chromogenic reactions.


2013 ◽  
Vol 6 (3) ◽  
pp. 371-380 ◽  
Author(s):  
Rachel N. Brownsey ◽  
Guy B. Kyser ◽  
Joseph M. DiTomaso

AbstractUnderstanding seed characteristics and seedling establishment patterns is essential for the development of effective management strategies for invasive annual species.Dittrichia graveolens(stinkwort) has increased its range rapidly within California since 1995, yet its biology is not well understood, which has led to poorly timed management. In this study, seed viability, germination, longevity, and dormancy, as well as seedling emergence characteristics ofD. graveolenswere evaluated in field, greenhouse, and laboratory experiments in Davis, CA, over a 2-yr period (fall 2010 to summer 2012). In the laboratory, seed germination ofD. graveolensoccurred at a wide range of constant temperatures (12 to 34 C). Cumulative germination was comparable to total seed viability (80 to 95%) at optimal germination temperatures, indicating that primary (innate) dormancy is likely absent. The base temperature for germination was identified using a thermal time model: 6.5 C and 4 C for 2010 and 2011 seed populations, respectively. In the field, seedlings emerged from fall through spring following precipitation events. A very low percentage of seedlings (2.5%) emerged in the second year after planting. Equivalent seedling emergence was observed over a wide range of light conditions (100, 50, 27, and 9% of available sunlight) in a greenhouse experiment, indicating that seed germination is not limited by high or low light. Results from these seed experiments improve our understanding of the reproductive biology of this rapidly expanding exotic annual and provide valuable information for developing effective timing and longevity of management programs.


2013 ◽  
Vol 31 (2) ◽  
pp. 259-266 ◽  
Author(s):  
A. Sadeghloo ◽  
J. Asghari ◽  
F. Ghaderi-Far

Abutilon theophrasti and Barnyardgrass (Echinochloa crus-galli) are major weeds that affect cropping systems worldwide. Laboratory and greenhouse studies were conducted to determine the effects of temperature, pH, water and salinity stress, and planting depth on seed germination and seedling emergence of Velvetleaf and Barnyardgrass. For Velvetleaf, the base, optimum and ceiling germination temperatures were estimated as 5, 35 and 48 ºC, respectively. Seed germination was sensitive to drought stress and completely inhibited by a potential of -0.6 MPa, but it was tolerant to salinity. Salinity stress up to 45 mM had no effect on the germination of Velvetleaf, but germination decreased with increasing salt concentration. Drought and salinity levels for 50% inhibition of maximum germination were -0.3 MPa and 110 mM, respectively. Seed germination of Velvetleaf was tolerant to a wide range of pH levels. For Barnyardgrass, the base, optimum and ceiling germination temperatures were estimated as 5, 38 and 45 ºC, respectively. Seed germination was tolerant to drought stress and completely inhibited by a potential of -1.0 MPa. Salinity stress up to 250 mM had no effect on seed germination. Drought and salinity levels for 50% inhibition of maximum germination were -0.5 MPa and 307 mM, respectively. A high percentage of seed germination was observed at pH=5 and decreased to 61.5% at acidic medium (pH 4) and to 11% at alkaline medium (pH 9). Maximum seedling emergence of Velvetleaf and Barnyardgrass occurred when the seeds were placed on the surface of the soil or at a depth of 1 cm.


HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 778-781 ◽  
Author(s):  
Andrés R. Schwember ◽  
Kent J. Bradford

Seed priming (controlled hydration followed by drying) is used to alleviate high temperature inhibition of germination and improve seedling emergence of lettuce (Lactuca sativa L.) and other species. However, seed priming can also reduce the longevity of seeds during dry storage. Alternative drying methods [i.e., slow drying or moisture content reduction (MCR) before drying] can extend seed longevity compared to conventional rapid drying procedures after priming. Three postpriming drying treatments were tested on `Conquistador' and `Genecorp Green' lettuce seeds: rapid drying, slow drying and MCR (10% fresh weight loss, then held at 100% relative humidity (RH) for 6 hours, followed by rapid drying). The effects of the postpriming treatments on seed quality and longevity were compared based upon standard germination tests, germination rates, thermogradient table tests, controlled deterioration (CD) tests, and headspace volatiles analysis. The latter may be correlated with seed longevity as release of volatiles (e.g., acetaldehyde, ethanol) is associated with lipid peroxidation. While neither slow drying nor MCR before drying restored lettuce seed longevity to that of the control (not primed) seeds, the MCR method generally gave better results in both cultivars compared to rapid drying. Among the CD test conditions used, 50 °C and 75% RH gave the most consistent results for estimating potential longevity. Headspace volatile emissions from both control and primed lettuce seeds were very low and were not well correlated with seed longevity. Alternative postpriming drying regimes can extend seed longevity while retaining the beneficial effects of priming.


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