الفهرس 
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Abstract
AND CONCLUSIONS
The present study was carried out in the Egyptian Deserts Gene Bank (EDGB), North Sinai Research Station, Desert Research Center, Egypt, during the period from 2005 to 2008. The aim of this study was to investigate the seed viability response of storage conditions under storage conditions of room temperature, +4 oC and -22 oC and storage periods (fresh seeds ”control”, 6 months, 12 months and 5 years) and using different breaking dormancy treatments, on germination percentage, standard germination percentage, dormancy percentage, viability percentage and germination rate of four wild plants (Balanites aegyptiaca (L.) Del, Citrulus colocynthis (L.) Scharad., Solenostemma argel (Del.) Hayne. and Zygophyllum coccineum (L.). and using SDS-PAGE in seeds and tetrazolium test in determine seeds viability.
The important results can be summarized as follows:
1- Viability parameters:
1.1. Effect of seeds storage conditions:
1. Storage of Balanites aegyptiaca (L.) Del, Citrulus colocynthis (L.) Scharad., Solenostemma argel (Del.) Hayne. and Zygophyllum coccineum (L.) seeds under room temperature exhibited lesse germination percentage than the other storage conditions used. Higher germination percentages was obtained were +4 ºC and -22 ºC as mostly increased the germination percentage.
2. Highest germination percentage was obtained under -22 ºC storage conditions for seeds of wild plants.
1.2. Effect of seed storage periods:
1. Seeds viability gave the highest value in fresh seeds
2. Storage of seeds for 6 or 12 months gave the highest value of viability parameters.
2- Germination rate
2.1. Effect of seeds Storage conditions:
In general, storage under low temperature conditions i.e. under-22 ºC and +4 ºC could increase the germination rate
2.2. Effect of storage periods:
Different period of storage. as well as, storage under +4 ºC and -22 ºC gave the highest germination rate after 6 and 12 months, respectively. Moreover, the opposite trend was true with storage under room temperature at all storage periods.
1. Balanites aegyptiaca (L.) Del
I. Effect of seeds storage conditions:
Effect of seeds storage conditions (room temperature, +4oC & relative humidity of 40 % and -22oC on viability parameters of Balanites aegyptiaca (L.) Del. Results revealed that significant differences were detected between the storage conditions in all parameters, unless D%. the least results achieved when seeds were stored under -22 oC, while, room condition gave the least values in all parameters unless D% which appeared with base room. It could be concluded that decreasing storing temperature to -22 oC caused an increase in G%, SG%,V% and GR.
II. Effect of seed storage periods:
The results showed that there were significant differences between all storage periods and all viability parameters. Seeds stored up to 12 months gave the highest germination percentage and standard germination percentage. While the least value of these parameters appeared with fresh seeds, which gave the highest values of viability percentage and germination rate. However parameters gave the least values with seeds, stored for 5 years.
III. Effect of pre-sowing treatments
Results are showed an increase in germination percentage from 40.03 to 73.50 %, standard germination percentage from 39.03 to 70.62% and germination rate from 0.99 to 1.30 when seeds were treated with dry heat 60 oC for 15 min. while, the highest dormancy percentage (58.97%) was obtained with control treatmen. Also, when seed were soaked in normal water for 72 h and treated with GA310-3M for 24 h gave the highest viability percentage. untreated (control treatment) seeds achieved the highest dormancy value.
Pre-treated seeds of B. aegyptiaca with dry heat 60 oC for 15 min enhancing the seed germination.
IV. Tetrazolium test:
stored seeds up to 6 and 12 months under room temperature decreased viability percentage from 100 to 48 %, while storing seeds for five years under -22 oC enhanced the viability percentage but storing seed under room temperature for five years decreased the viability percentage.
2. Citrulus colocynthis (L.) Scharad.
1. Effect of storage conditions:
Stored seeds of Citrulus colocynthis under room temperature conditions showed a significant decrease in germination percentage as compared with the other storage conditions i.e. +4 ºC and -22 ºC, as seeds stored at +4 ºC gave less value. Higher germination percentage was obtained at -22 º C and standard germination percentage gave the same trend, at the different storage periods.
2. Effect of storage periods:
Storability of seeds up to 6 or 12 months developed germination percentage.
3.Effect of the interaction between storage conditions at the different storage periods.
Higher germination percentage was obtained after 12 months under -22°C storage conditions, while, storing seeds up to 5 years under room temperature decreased the germination percentage. Standard germination percentage gave the similar trend.
4. Effect of pre-sowing treatments
Results showed an increasing in germination percentage from 31.65 to 77.77 %, standard germination percentage from 29.44 to 73.40 % and germination rate from 3.369 to 10.67 when seeds were treated with H2O2 for 24 hours. while the highest dormancy percentage (63.36 %) was with control treatment. Treated seeds with mechanical scarification gave the highest viability percentage. However, the seed untreated (control treatment) achieved the highest dormancy value.
3. Solenostemma argel (Del.) Hayne
1. Effect of storage conditions
Highest values of germination percentage were (74.85), standard germination percentage (71.21), viability percentage (97.72) and germination rate (1.873), when storing seeds in base room -22oC, while the least values were when storing seeds under room temperature
2. Effect of storage periods:
Storage seeds up to 6 months gave the highest germination percentage, standard germination percentage and germination rate. and the storage of seeds for 6 months led to an improvement in the germination of seeds from 68.34 to 74.31%. In addition, storage of seeds for 12 months led to improving the germination of seed from 68.35 to 70.45%, while, storage for a period of 5 years led to keep the germination percentage at the same level.
3. Effect pre-sowing treatments:
Results showed an increasing in germination percentage from 67.54 to 83.16 %, standard germination percentage from 39.03 to 78.23 % and germination rate from 1.840 to 2.144 when seeds were treated with K2MnO4 0.2% for 1hour. While when seeds were treated with KNO3 0.2% gave the same trend as results showed an increasing in germination percentage from 67.54 to 83.06 %, standard germination percentage from 39.03 to 79.45 %, viability percentage from 94.44 to 96.34 % and germination rate from 1.840 to 2.192. followed by KNO3 0.5%.
4. Zygophyllum coccineum (L).
1. Effect of storage conditions:
The resuls gave the highest germination percentage and viability percentage when seeds were stored under -22oC. Standard germination percentage and dormancy gave the highest values with room temperature storage. Germination rate gave different values between storage conditions.
2. Effect of storage periods:
The highest germination percentage was obtained when seeds were stored for six months, 12 months and fresh seeds, as all parameters gave the same trends. Without germination rate, results gave the highest values in fresh seed and storing seeds for five years. The same trends were obtained with dormancy for five years ago.
Fresh seeds under room temperature gave the highest value of viability percentage and germination rate, as well as seed stored under +4 oC gave the same trend for conservation seeds under different conditions. Storage of seeds under all storage periods especially for 5 years decrements viability percentage, but storing in -22 oC saved the seeds viability and germinability.