原版拟南芥规范种植手册

normal seed production, seeds are harvested only after the siliques have

completely browned, and when pressed with fingers, do not compress (if the

silique has dried even further, the silique may shatter at this point). At this stage, seeds are completely formed. Since formation and maturation of siliques occur over time, early siliques can be harvested before later ones mature to avoid seed loss. However, it is usually recommended to wait until the entire inflorescence has browned before harvest.

SEED HANDLING AND PRESERVATION

The longevity of seeds can be affected by a) genotype, b) pre-storage environment, such as conditions during seed maturation, harvesting and seed handling and c) seed storage conditions. A slow process of deterioration begins as soon as seeds mature on a plant. Therefore the sooner seeds are placed into storage, the better. Harvested seeds should be processed promptly (including threshing, cleaning, drying and packaging) and then placed into storage.

Preservation of seeds involves adherence to a few simple principles. Hence, it is not a difficult task although deviations can result in damage to seeds. We treat Arabidopsis as oil seeds which means that the most careful, and conservative handling procedures must be applied. The following procedures form a sequence that ensures that the seeds will be conserved in the best possible condition.

Hand rather than machine threshing and cleaning of the small Arabidopsis seeds is recommended mainly because the threshing machines need rigorous cleaning between lines to avoid sample cross-contamination, require very careful adjustment and do not accommodate the variable size of Arabidopsis seeds well.

If seeds are collected in a plastic bag, the harvested plant material should be allowed to dry for a few days in the opened bag before threshing, since threshing is easier when the inflorescences are dry. Seeds should be threshed when the moisture content is approx 10%, to minimize seed damage during threshing. This moisture content will be reached when all material in the bag appears to be dry. The plastic bags containing dried

inflorescences can be gently hand-pressed from the outside, and the seeds will fall to the bottom of the bag. Most of the dry inflorescence can be removed from the bag by hand before seeds are sieved to separate them from chaff.

Hand sieves with graded mesh sizes (i.e. No. 40) are recommended to remove debris, with seeds passing through the mesh and collected on clean paper. Totally dry plants from AraconsTM and sleeves can be placed directly onto the sieve. After sieving, the seeds are still likely to be mixed with soil and residue. A combination of additional sieving, blowing and visual inspection can be employed to clean the seeds completely. Small samples can be cleaned by hand with the aid of a pointed tool on an opaque glass plate illuminated from below. Cleaned seed samples are placed in open, carefully labeled