“Technological Advances in Seed Priming ”
Seed Science and Technology
(College of Agriculture , CSKHPKV, Palampur)
Speaker : Ramesh Kumar
Seed plays a crucial role in agriculture since ancient times. It is the
starting point, first determinant of the future plant development and the
most important factor for successful production.
Vigorous and high quality seeds will ensure the advantageous expected
after the application of other means of production such as watering or
Various techniques are available, which have the potential to improve
emergence and stand establishment under wide range of field
Seed priming is on of the physiological ways which enhances
performance of seed and seeds show rapid and synchronised
• Seed priming is one of the most important developments to help rapid & uniform
germination & emergence of seeds and to increase seed tolerance to adverse environmental
(Heydecker et al. 1973, 1975)
• Seed priming is a controlled hydration process followed by re-drying that allows seed to
imbibe & begin internal biological processes necessary for germination, but not allow the
seed to germinate. (Kathiresan et al. 1984)
• Priming allows some of the metabolic processes necessary to occur without germination
take place, seeds are soaked in different solutions with high osmotic potential this prevents
the seed from absorbing enough water for radicle protrusion thus suspending the seeds in
lag phase. (Taylor et al. 1998)
• Seed priming improves the germination rate, speed and uniformity even under less than
optimum field conditions thus enabling the establishment of uniform & good crop stand
establishment. (Lee et al. 1998, Kant et al. 2006)
• Primed crops grew more vigorously, flower earlier & gave higher yield.
(Farooq et al. 2008) 3
4. What is seed priming ?
• It is a pre-sowing treatment in which seeds are soaked in osmotic
solution that allows the seeds to imbibe water and go through the first
stages of germination but does not permit radicle protrusion through
the seed coat
• It is based on the principle of controlled Imbibition, to a level that a
permits pre germination metabolism to proceed, but prevents actual
emergence of radicle.
( Bradford, 1986 )
5. Why seed priming ?
• Increases the seed emergence
• More uniform crop stand
• Fast emergence
• Increase the yield
• Get the good crop stand in stress conditions
• Increase the quality of the seed
6. Seed priming: History
300 BC Theophrastus Cucumber seeds soaked in water prior to sowing would induce faster
1600 Oliver de Serres "clever trick“ of soaking grains (wheat, rye or barley) for two days in
manure water followed by drying in the shade before planting the
seeds. Soaked seeds emerged more quickly avoiding "the danger of
being eaten away by soil pests".
1855 Charles Darwin Possibilities for osmotic seed priming. Darwin submerged seeds in salt
water to show that they could move across the sea between
landmasses as a means to explain geographic distribution of plant
species. The seeds survived in cold salt water for several weeks and
showed accelerated germination.
1883 Will Repeated soaking and drying of the seeds results in drought and frost
1964 Henckel Soaking seeds in water for about 48 hrs at 10oc- 15oc and drying back to original
weight induced drought tolerance in plants.
1971 Malnassy Coined the term "Seed Priming”
1975 Heydecker Acknowledged the term seed priming which is synonymous with seed invigouration;
introduced the terms halopriming and osmopriming.
1988 Taylor et al. Introduced the term "Solid Matrix Priming" (SMP)
1990 Khan et al. Proposed "Matriconditioning" as alternative for SMP
1990 Callan et al. Coined the word "Biopriming”
8. Seedpriming:Physiological &biochemical basis
• Seed priming reduces the imbibitional damage associated with planting
seeds in cold soils and results in less secondary dormancy (e.g., Lettuce),
caused by planting seeds in excessively warm soils.
• The primed seeds leaks less metabolites, seed endosperm is hydrolysed
during priming that permits faster embryo growth and cell wall elasticity is
• Hydration of the seed during priming permits early DNA replication,
increased RNA & protein synthesis and more ATP availability.
• Increase in seed vigour may also occur following seed priming, as repair of
deteriorated parts of seed occurs during the hydration phase of the
1. Stages of water uptake during germination where priming is relevant:
The pattern of water uptake during priming is similar to that during germination but the rate
of uptake is slower and controlled to prevent radicle emergence.
2. Changes in protein profile:
• Proteomic analysis in Arabidopsis revealed that new proteins are involved either in the
imbibition process of the seeds (such as an actin isoform or a WD-40 repeat protein) or in
the seed dehydration process (e.g. cytosolic glyceraldehyde-3-phosphate dehydrogenase)
which helps to characterize seed vigor of commercial seed lots and to develop and monitor
priming treatments. Gallardo et al. (2001)
• Increased σ-amylase activity and sugar content were reported in the treated seeds
compared with the control when rice seeds are primed with KNO3. Basra et al. (2005)
• Some proteins were synthesized only during priming and not during germination eg. the
degradation products of certain storage proteins (such as globulins and cruciferin) are
detected only during priming and not when imbibed in water. Anuradha Varier et al. (2010)
10. 3. Enzyme activation in relation to priming:
• Increases in activities of σ-amylase in rice (Basra et al. 2005, Farooq et al. 2006b), acid
phosphatase and esterase in lettuce (Khan et al. 1978), and antioxidant enzymes in
Lucerne(Zhang et al. 2007).
• A rapid resumption of DNA synthesis and initiation of cell division in wheat soon after
hydration. (Dell'Aquila and Taranto,1986)
• Repair of DNA and other cellular components (e.g. membranes), which may be damaged
during seed maturation, dehydration and storage DNA repair may be a major contributing
factor to the improvement in germination after osmopriming. (Burgass and Powell, 1984)
• Primed seeds had less lipid peroxidation and higher superoxide dismutase (SOD) &
catalase (CAT) activities than non-primed rice seeds.
• Enzyme activities of catalase, peroxidase, amylase and invertase increased in PEG treated
seeds. (Singh et al.1985)
12. Priming-molecular basis:
Unchanged DNA content of tomato Coolbear and Grierson (1979)
Increase in DNA synthesis and DNA repair (Bray et al.,1989 (Leek); Dell'Aquila and Taranto,
1986 (wheat) ; Coolbear et al., 1990 and
Yongging et al., 1996 (tomato cv. Moneymaker);
Lanteri et al., 1994 (pepper); Asraf and Bray,
1993 (Leek); Gurusinghe et al., 1999 (tomato))
and (Fu et al., 1988).
Improvement in germination by priming might be due to
enhanced repair of membrane, which was disrupted during
maturation drying. This was indirectly supported by the
reduced leakage of electrolytes from primed seeds, since
electrolyte leakage is in part a result of damage cell
Chiu et al. (1995)
• Priming also has been shown to induce nuclear DNA synthesis in the radicle tip cells in
tomato (Liu et al., 1997) and several other plant species, including maize (Zea mays L.).
(Garcia et al.1995)
• Wild oat seeds, primed with 30% PEG for 24h resulted in increase in the activity of
superoxide dismutase (SOD) and peroxidase (POD) and a rapid increased in the
respiration intensity, which were associated with increase in germination and vigor.
( Jie et al., 2002)
• Osmopriming may also contribute to rapid speed germination by reducing the mechanical
restraint of endosperm on developing embryo.
(Mayer and Mayber, 1989)
• Osmopriming of tomato seed increased the endo-beta mannanase activity in the
endosperm cap and decreased its mechanical restraint on the germination embryo.
(Toorop et al.1998)
• Osmotic seed priming is a pre-sowing treatment in which seeds are soaked
in osmotic solution that allows seeds to imbibe water to proceed to the first
stage of germination but prevent radicle protrusion through the seed coat.
Heydecker et al. (1973)
• Osmotic priming of seeds also known as osmopriming or osmoconditioning
describes incubation of seeds with aerated solutions of low water potential
which are rinsed off afterwards. e.g. polyethylene glycol (PEG), glycerol,
sorbitol, or mannitol are used as osmoticants to creates low water potential
• Osmopriming essentially exposes seeds to a low water potential to restrict
the rate and extent of imbibition.
• Osmopriming is akin to a prolonged early imbibition of seeds that sets in
motion a gradual progression of various pre-germinative metabolic activities.
17. 1. Wild rye (Leymus chinensis L.) seed priming with 30% PEG for 24 h resulted in increase in the cell activity
of superoxide dismutase, peroxidase & a rapid increase in the respiratory intensity which were associated
with an increase in germination & vigour.
Jie et al. (2002)
2. Chickpea seed primed with water, 2 & 4 % mannitol increased the length and biomass of roots and shoots
of seedlings as compared to non-primed control under salt stress conditions.
Kaur et al. (2002, 2005)
3. Muskmelon (Cucumis melo L.) seed osmo-conditioned with PEG-6000 showed enhanced activity of
dehydrogenase & amylase & improved germination under non-saline conditions.
Singh et al. (1999)
18. • Halopriming refers to soaking of seeds in solution of inorganic salts i.e.
NaCl, KNO3,KCl, KH2PO4,CaCl2, CaSO4 etc.
• Germination and vigor of less vigorous cabbage seed enhanced when
primed with KNO3 2 % and KH2PO4 2 %.
(Batool et al., 2014)
19. Effect of Halo-priming:
1. Seeds of muskmelon soaked with KNO3 solution showed enhanced activity of dehydrogenase and alpha
amylase under low temperature.
Singh et al. 1999
2. Rice seeds treated with KCl (1%) recorded significantly higher plant height, seed yield and 100 seed
weight over control.
Jayaraj and Sasikala, 2004
3. Soaking of maize seeds in KH2PO4 solution significantly increased the germination, speed of emergence,
mean daily germination, shoot length, root length, seedling vigour index and seedling dry weight over
Ramalal et al. 1993
20. • Hydropriming involves soaking of seeds in water before sowing and may
or may not be followed by air drying of the seeds.
• Seeds are immersed in sterilised distilled water kept at appropriate
temperature and the duration of hydro-priming is determined by
controlling seed imbibition during germination. (Kaya et al. 2006)
22. Effect of Hydro-priming:
1. Enhancement of physiological and biochemical events taking place in seeds even when the germination
is suspended by low osmotic potential and negligible matric potential of the imbibing medium .
Basra et al.2003
2. A simple, economical and a safe technique for increasing the capacity of seeds towards osmotic
adjustment, enhancing seedling establishment and crop production under stressed conditions.
Kaur et al. 2002
3. Increased activity of á-amylase which in turn has resulted in better mobilization of stored carbohydrate
reserves resulted in improvement of germination and other related parameters.
Kata et al. 2014
4. Soaking of wheat kernels in water improved their germination rate under saline conditions.
Roy and Srivastava. 1999
• In solid matrix priming or matric conditioning , solid or semi solid medium is used as an
alternative to liquid medium. (Copeland and McDonald 1995)
• Technique is accomplished by mixing seeds with a sloid or semisolid material and
specified amount of water.
• Water is slowly provided to the seeds & thus slow or controlled hydration occurs
allowing the repair mechanism to operate.
• Commonly used solid matrics includes Cocopeat, Perlite, Vermiculite, moss, Saw dust,
Sand exfoliated vermiculite, expanded calcined clay etc.
24. 1. Solid matrix priming with animal compost (SMP) for 12 and 24 hrs was the most effective treatment
in improving overall germination percentage and seedling emergence of rapeseed.
Bijanzadeh et al. 2010
2. Solid matix priming was effective in invigorating seeds of soybean through improvement in seed
Mercado and Fernandez.2002
3. Solid matrix priming in combination with Trichoderma viride can be successfully used to improve
seedling emergence and productivity of okra under low temperatures.
Pandita et al. 2010
25. • Bio-priming is a process of biological seed treatment that refers to combination of seed
hydration (physiological aspect of disease control) and inoculation (biological aspect of
disease control) of seed with beneficial organism to protect seed.
• It is an ecological approach using either bacteria or selected fungal antagonists against the
soil and seed-borne pathogens.
• Applying beneficial microorganism to the seed during priming may further improve
establishment of the crop, particularly if seed-applied microorganism subsequently become
established in the root zone of the plant and contribute to the long term plant health or
plant growth promotion.
(Bennett and Whipps. 2008)
26. Benefits of bio-priming in crops using biocontrol agents:
Crop Biocontrol agents Disease control Reference
Sunflower Osmopriming with NaCl &
Biopriming with Pseudomonas
(0.8%) in jelly
Moeinzadeh et al.
Rao et al. (2009)
Maize Trichoderma harzianum Fusarium verticillioides
Chandra Nayaka et al.
Carrot Antagonist, Clonostachys rosea Alternaria dauci & A.radicina Jensen et al. (2004)
Pearl millet Pseudomonas fluorescens Downy mildew Raj Niranjan et al.
27. Effects of Bio-priming
1. Wheat seed bio-priming with different salinity-tolerant isolates of Trichoderma were effective in
improving germination percentage and reducing reduction percentage of germination during salinity
Rawat et al. 2011
2. Application of plant growth-promoting rhizobacteria (PGPR) improves the percentage of seed
germination under saline conditions and also increased the shoot length, root length and dry matter
in chickpea (Cicer arietinum L.).
Mishra et al. 2010
3. Trichoderma viride improved the plant length, maximum number of pod and pod diameter in okra
and concluded that the bio-priming will enhance the plant growth and yield attributes.
Rai and Basu, 2014
28. • This is misting of seed with water and re-drying before they
complete germination. Seeds are rotated in a drum with specific
amount of water introduced as a fine mist.
• As the seeds absorb water, a sensitive scale monitors increase in
seed weight until the desired wet weight is achieved.
29. • Hormonal priming is the pre seed treatment with different hormones i.e.
salicylic acid, ascorbate, kinetin, etc. which promote the growth and
development of the seedlings.
• The seeds were soaked in aerated solution of hormones like GA, kinetin,
ABA, proline and salicylic acid (SA @ 10 & 20 ppm)
30. 1. Seed performance of various crops can be improved by inclusion of plant growth regulators and
hormones during priming and other pre-sowing treatments.
Lee et al. 1998
2. Abscisic acid (ABA) is a phyto-hormone extensively involved in response to abiotic stresses such as
drought, low temperature and osmotic stress.
Fujita et al. 2006
3. Sorghum seed primed with gibberellic acid, salicylic acid and ascorbic acid increased germination
characteristics of seed aged. Antioxidant activity of aged seeds increased after seed priming.
Azadi et al. 2013
32. Effects of Magneto seed priming:
1. SMF dose of 100 mT for 30 min gave maximum increase in germination characteristics.SMF primed
seeds were then exposed to pulsed magnetic field (PMF) dose in the cycles of 2, 3, 5 or 6 min on and
off where PMF dose of 3 min on and off cycle showed substantial enhancement of 23 % in seedling
vigour compared to other treatments.
Gupta et al., 2015
2. Magneto-priming of cucumber seed at 200 mT magnetic field for 1 hour improved germination
parameters, water uptake, transverse relaxation time , activities of hydrolytic enzymes, amylase and
protease and activities of antioxidant enzymes, superoxide dismutase, catalase and glutathione
Bhardwaj et al., 2012
33. Nano seed priming
• It is the process of seed priming in which seeds are primed with the nano
particles like Sio2, Tio2 and silver nano particles are used.
• Nano-particles target specific cellular organelles in seeds to release their content.
• Nano-particles enhance water uptake in seeds and activate enzymatic and
hormonal responses during seed germination and plant growth.
34. Effects of Nano priming:
1. Sorghum seeds primed with Nanoparticles of iron at two levels doses of priming at five levels (normal,
bulk, 0.01%, 0.02%, 0.03%), pre- treatment temperature at two levels (100C and 150C) and had
significant effect on some of the features in seedlings such as some of enzymes, unstructured
carbohydrates and types of the chlorophylls.
2. AgNPs primed wheat and barley seeds show significant increase in the germination percentage,
compared with those percentages of control, results showed that use of nanoparticles increased
extent of seedling vigor index in plants compared to the control. AgNPs influenced growth parameters
as well as photosynthetic pigments and chlorophyll fluorescence.
(Abou-Zeid and Moustafa, 2014)
35. List of crops, priming techniques used and their effects:
crop Chemical used for
seed priming and
Effects on crop Authors
Paddy KNO3 , KCl, CaCl2
NaCl & Mannitol
Increased seed quality parameters and
resultant seed quality
Increase the yield emergence, seedling
fresh weight and dry weight
Geetha (1992) & Nagaraj
Farooq et al., (2005)
Wheat PEG 8000 and KN03 Germination parameters Salehzade et al, 2009
Barley Water soaking for 12-16 h priming was also more advantageous on
saline-sodic than on saline soils
Rashid et al., 2006
Maize Urea, PEG, GA3-
Increased seed quality parameters
Increased emergence, seedling fresh
weight and dry weight
Pegah et al., (2008)
Afzal et al., (2008)
Sorghum KH2PO4 2%
DAP 2%, micronutrient
increased seed quality parameters Salvaraju, (1992)
36. crop Chemical used for seed
Effects on crop Authors
Soybean NaCl 0.5%, KNO3 1%, DAP
Increased growth and yield
Cotton Ca(OH)2 (2/4%), KCl (1%) Increased seed quality parameters,
field emergence and vigour of seeds
Tomato Sodium phosphate (dibasic) Increased the seed quality
parameters and controlled the
microbial activity and extending the
shelf life of seeds
Sree Rama Murthy,
Bhendi CaOCl2 2% Increased seed quality parameters Sambandhamani,
Onion Hydropriming, Solid matrix
priming, Osmopriming - 0.25
MPa PEG ,Halopriming 3%
KNO3 and NaCl
Increased seed germination bility
38. Advantages of seed priming
• Early field emergence and good field stand.
• Increase the seed vigour of low vigorous seeds.
• Increase the germination percentage.
• Helps in uniform field stand in stress conditions.
• Improves the shelf life of seeds
• Increase the yield.
• Imbibition injury prevented
• Salt priming supply seeds with nitrogen and other nutrients for protein synthesis
• Priming Requires specific temperature and time, if it is not followed then seed can
be deteriorate due to embryo protrusion.
• Osmotic seed treatment is expensive.
• There should be continuous aeration to seed in the solution, otherwise the seed
will suffer from the ill effects of anaerobic aeration.
• As the treatment is done over a long period, proper caution against microbial attack
should be taken.
44. Effect of seed priming with chemicals and PGRs on germination percentage, yield and yield
contributing traits of wheat varieties under sodic soil:
Number of tiller
No. of grains
Control 68.75 82.89 6.45 33.97 7.84
Hydropriming 73.08 85.38 6.74 37.28 8.44
KNO3 3% 80.92 93.70 7.92 44.78 9.51
KCl 1% 77.75 90.65 7.33 41.50 9.34
GA3 150ppm 76.25 89.48 7.33 39.36 8.93
Cycocel 500ppm 74.50 81.17 7.12 38.17 8.72
CD at 5% 2.55 3.80 0.88 2.08 0.61
Kalpana et al. 2013 44
45. Chemical priming for improved seed yield and quality in black gram var CO5.
Water 81 42.1 719 4.321 90 3069
KCl 1% 89 50.0 847 4.982 92 4545
KH2PO4 1% 89 44.6 738 4.880 90 3942
CaCl2 1% 85 44.4 746 4.660 91 4050
KNO3 0.5% 83 48.7 724 4.412 90 3627
Control 76 39.4 699 4.410 85 3196
CD 0.05% 2.12 1.18 9.7 0.27 3.11 29.7
Srimathi and Sujata. 2006 45
46. Future thrust
• Developing a complete priming protocol must address the balance between germination
advancement and reduced seed longevity.
• Attempt to attain the most rapid germination from priming must be weighed against the
enhanced liability of this pre-sowing treatment.
• The challenges of technology to enhance seed performance provides an opportunity for
more in-depth studies on physiological and biochemical changes that occur during seed
• Physiological, biochemical and biophysical markers are needed to detect the enhanced
quality of seeds.
• Identification of diagnostic markers which might be employed to interrogate gene expression
to characterize seed quality and to develop and optimize priming enhancement procedures.46
• Advanced technologies like nano-priming may further be improved using bio-
nanoparticles which may be beneficial to the seed because the nanoparticles penetrate
deep in the tissue of seeds.
• Efforts will have to be made to determine the right time and right quantity of priming
(time and solute infusion). Packing techniques have to be developed to store primed
seed. Such techniques will revolutionize farming in moisture starved areas where
farmers are poor technologically and traditionally.
• More research has to be done in the area of using botanicals and use of microbial
consortia for biopriming.
48. • Seed priming can enhance the quality of seed by influencing the fast germination and
uniform field stand that result in the increase in the yield.
• Seed priming with hormones cause the stress tolerance in the plant and stimulate the
germination in the stress and drought conditions.
• Magneto-priming of seed doesn't require the hydration of seed that is beneficial for seed
because seed longevity is not affected.
• Priming with nanomaterials enhance water uptake in seeds and activate enzymatic
activity in the seed that result in faster emergence.
• Seed priming has emerged as a promising strategy in modern stress management
because it protects plants against various abiotic stresses without effecting fitness.