into storage. It should be noted that delays in harvesting following
physiological maturation of the plant result in seed deterioration,
especially under nonoptimal environmental conditions.
Seeds should be threshed when the seed moisture content is
approximately 10%, to minimize seed damage during threshing.
This seed moisture content will be reached when all plant material
appears to be dry. Hand, rather than machine threshing, is recommended mainly because threshing machines need rigorous cleaning
between lines to avoid sample cross-contamination and require very
careful adjustment for the variable size of Brassicaceae seeds. Hand
threshing is performed as follows:
1. Set a large, clean, sheet of white paper on a bench or table for
collection of the threshed seeds.
2. Place a clean threshing sieve on top of the paper (see Note 41).
3. Remove the plant isolation device and cut the plants (see Note
42).
4. Place dry plants directly onto the sieve. If plants are larger than
the sieve, they can be cut into pieces that fit into the sieve.
5. Crush plants with your hands to remove all the seeds from the
siliques/silicles. Discard plant material.
6. Sieve seeds through the mesh repeatedly until free of chaff (see
Note 43).
7. Place cleaned seed samples in small labeled coin envelopes or
open glass jars to allow seeds to air-dry. Do not use plastic due
to static effects.
Preparation for Storage
The ideal moisture content of seeds for storage is 5–6%. Higher
moisture content can cause seed deterioration. The recommended
method is to air-dry the seeds at room temperature with approximately 20% RH for 1–3 weeks (see Note 44). Low RH (20–30%) is
necessary for seeds to reach the desired moisture content
[10, 11]. Seed moisture content can be determined by several
methods [12]. Seed packaging for storage can be accomplished as
follows:
1. Use cryovials (with threaded lids and gaskets) for convenient
and safe storage. They hold large numbers of seeds, seal tightly,
are moisture-proof, and can be resealed many times.
2. Label each vial with pertinent information including date of
storage.
3.3.2 Seed Storage
and Preservation
The general conditions for preserving optimal viability of seeds
have been well defined [10, 11, 13–15]. Seed storage principles
for Brassicaceae are similar to those for other plants, with the caveat
that small seeds rehydrate very rapidly if exposed to high humidity.
When seeds deteriorate, they lose vigor and eventually the ability to
12
Christopher Calhoun et al.
physiological maturation of the plant result in seed deterioration,
especially under nonoptimal environmental conditions.
Seeds should be threshed when the seed moisture content is
approximately 10%, to minimize seed damage during threshing.
This seed moisture content will be reached when all plant material
appears to be dry. Hand, rather than machine threshing, is recommended mainly because threshing machines need rigorous cleaning
between lines to avoid sample cross-contamination and require very
careful adjustment for the variable size of Brassicaceae seeds. Hand
threshing is performed as follows:
1. Set a large, clean, sheet of white paper on a bench or table for
collection of the threshed seeds.
2. Place a clean threshing sieve on top of the paper (see Note 41).
3. Remove the plant isolation device and cut the plants (see Note
42).
4. Place dry plants directly onto the sieve. If plants are larger than
the sieve, they can be cut into pieces that fit into the sieve.
5. Crush plants with your hands to remove all the seeds from the
siliques/silicles. Discard plant material.
6. Sieve seeds through the mesh repeatedly until free of chaff (see
Note 43).
7. Place cleaned seed samples in small labeled coin envelopes or
open glass jars to allow seeds to air-dry. Do not use plastic due
to static effects.
Preparation for Storage
The ideal moisture content of seeds for storage is 5–6%. Higher
moisture content can cause seed deterioration. The recommended
method is to air-dry the seeds at room temperature with approximately 20% RH for 1–3 weeks (see Note 44). Low RH (20–30%) is
necessary for seeds to reach the desired moisture content
[10, 11]. Seed moisture content can be determined by several
methods [12]. Seed packaging for storage can be accomplished as
follows:
1. Use cryovials (with threaded lids and gaskets) for convenient
and safe storage. They hold large numbers of seeds, seal tightly,
are moisture-proof, and can be resealed many times.
2. Label each vial with pertinent information including date of
storage.
3.3.2 Seed Storage
and Preservation
The general conditions for preserving optimal viability of seeds
have been well defined [10, 11, 13–15]. Seed storage principles
for Brassicaceae are similar to those for other plants, with the caveat
that small seeds rehydrate very rapidly if exposed to high humidity.
When seeds deteriorate, they lose vigor and eventually the ability to
12
Christopher Calhoun et al.