germinate. The rate of this “aging” is determined by interactions of
the temperature and moisture content at which seeds are stored,
and unknown cellular factors that affect the propensity for damage
reactions [10].
Rapid deterioration of seeds has not been observed for the
diverse collections currently maintained at ABRC. However, genotype may have an effect on long-term viability of seeds and storage
requirements. A large number of genes involved in embryogenesis,
reserve accumulation, and seed maturation have been identified.
For example, seeds of the abscisic acid-insensitive mutants fail to
degrade chlorophyll during maturation and show no dormancy,
leading to low desiccation tolerance and poor longevity
[16]. Seeds should retain high viability for long storage periods,
under proper conditions. With the increase of storage temperature
and seed moisture content, the life span of the seeds decreases.
Seeds left at room temperature and ambient RH lose viability
within approximately 2 years. Seed stored dry at 4
C or À20
C
should last decades. Below are three storage options for safe seed
preservation.
1. For active collections which are accessed often, store seeds at
4
C and 20–30% RH. Control of humidity is typically achieved
by a dehumidification system in the cold room. The control of
RH provides a safety factor in case seed containers are not
sealed properly.
2. For long-term or archival storage, the recommended temperature is subzero, preferably À20
C, and also preferably
20% RH.
3. For open containers such as envelopes, seeds can be stored at
15–16
C, with a RH maintained very carefully at 15%. Under
this controlled environment, seeds will maintain suitable low
moisture content [17]. Storing seeds at RH < 15% will not
increase
shelf-life
and
may
actually
accelerate
deterioration [11].
When vials are removed from cold storage, condensation of
moisture on the seeds and subsequent damage may occur. For vials
stored at 4
C, sealed vials must always be warmed to room temperature before opening. For vials stored at À20
C rapid rewarming (placing the sealed vial in a 37
C water bath for 10 min) is a
recognized method to minimize frost damage. If possible, working
with seed stocks should take place at low (20–30%) RH. If accumulation of condensation is suspected, vials should be left open in a
dry space (20–30% RH) until seeds have equilibrated before returning the vials to cold storage.
Handling Arabidopsis Plants
13
the temperature and moisture content at which seeds are stored,
and unknown cellular factors that affect the propensity for damage
reactions [10].
Rapid deterioration of seeds has not been observed for the
diverse collections currently maintained at ABRC. However, genotype may have an effect on long-term viability of seeds and storage
requirements. A large number of genes involved in embryogenesis,
reserve accumulation, and seed maturation have been identified.
For example, seeds of the abscisic acid-insensitive mutants fail to
degrade chlorophyll during maturation and show no dormancy,
leading to low desiccation tolerance and poor longevity
[16]. Seeds should retain high viability for long storage periods,
under proper conditions. With the increase of storage temperature
and seed moisture content, the life span of the seeds decreases.
Seeds left at room temperature and ambient RH lose viability
within approximately 2 years. Seed stored dry at 4
C or À20
C
should last decades. Below are three storage options for safe seed
preservation.
1. For active collections which are accessed often, store seeds at
4
C and 20–30% RH. Control of humidity is typically achieved
by a dehumidification system in the cold room. The control of
RH provides a safety factor in case seed containers are not
sealed properly.
2. For long-term or archival storage, the recommended temperature is subzero, preferably À20
C, and also preferably
20% RH.
3. For open containers such as envelopes, seeds can be stored at
15–16
C, with a RH maintained very carefully at 15%. Under
this controlled environment, seeds will maintain suitable low
moisture content [17]. Storing seeds at RH < 15% will not
increase
shelf-life
and
may
actually
accelerate
deterioration [11].
When vials are removed from cold storage, condensation of
moisture on the seeds and subsequent damage may occur. For vials
stored at 4
C, sealed vials must always be warmed to room temperature before opening. For vials stored at À20
C rapid rewarming (placing the sealed vial in a 37
C water bath for 10 min) is a
recognized method to minimize frost damage. If possible, working
with seed stocks should take place at low (20–30%) RH. If accumulation of condensation is suspected, vials should be left open in a
dry space (20–30% RH) until seeds have equilibrated before returning the vials to cold storage.
Handling Arabidopsis Plants
13