Improving the identification, handling and storage of “difficult” seeds ...

2.8. LIBYA presentation
The National Gene Bank of Libya
Dr. Ibrahim Ben Amer
Supporting On-Farm management & improvement of PGRFA (question 2.1)
So far, we do not have a direct contact with farmers for such activities. However, the seeds of stored
germplasm (local varieties, landraces, etc.) are available to breeders in ARC and to graduate
students in agricultural institutes for further research. On the other hand, some of the conserved
materials were collected either directly from the farmers or from local markets.
Germplasm storage facilities (question 5.3)
The seed conservation facilities include:
▪ Medium term cold storage room, 50m², with controlled temperature of 5ºC and RH at 35%
▪ Long-term storage in 2 deep freezers (-18ºC) is available, however they are not used because of
the lack of air vacuum pump and the proper seed containers
▪ Field conservation (on-farm conservation), located in research stations belonging to the
Agricultural Research Center, for fruit trees, citrus, date palm, olives, etc.
▪ So far there are no activities in in-vitro conservation and cryo-preservation.
Drying facilities/methods
The gene bank is equipped with a drying room of 18m², with controlled temperature at 20ºC and
15% RH. The sample is introduced to the drying room and monitored from time to time. When the
final weight is reached the sample is moved to conservation room.
Measuring seed moisture status
The initial moisture content of the collected seeds is determined after cleaning, using a hot air
drying oven:
▪ for starchy seeds 1-4 hours drying period at 133 o C
▪ for oily seeds 17 hours drying period at 103 o C
Large seeds are usually crushed before moisture determination. The seed moisture is adjusted to (6-
10 o C) using the drying room.
Storage containers
At the beginning of our work we used plastic containers of different sizes (depending on the
quantity of the seeds), however, we noticed frequent change in the RH of the conserved samples.
Therefore, we shifted to using air-tight glass gars with a rubber seal. A small bag of silica gel is
added to each container for visual monitoring of stable RH. In the case of a color change, the
moisture content of the conserved sample is re-determined, and if needed, re-dried.
Viability monitoring (question 5.5)
The viability of the seed collections is initially observed upon arrival to the gene bank. So far, we
only use germination percentage as an indicator of seed viability. We do not have yet any data on
species with low initial viability or species that demonstrate loss of viability after a period of
storage. However, we did notice with some Hordeum vulgare collections that the samples showed
low germination percentages in lab testing. However, when the seeds were planted in the field, they
showed a good level of germination. The problem we see for viability monitoring is the lack of
experience on how we can deal with forest trees and wild plants seeds which show a high degree of
dormancy.