الفهرس Only 14 pages are availabe for public view
 |  | from | 170 |  |  |
| | | from | 170 | | |
Abstract
Banana is considered one of the most important crops in the world. In spite of it is considered one of the most favorite fruit for Egyptian peoples and others in many countries; it is one of the most important sources for national income. In this study, several experiments were carried out; and they resulted in the following informations:
1- Tissue culture techniques have shown a high potential as a plant biotechnology tool to control the experiment conditions and production of artificial seeds.
2- Micropropagation of banana was carried out using small size and cone shaped shoot tip explants consist of the apical meristematic dome covered with a number of leaf initials and measuring 5-7 mm in length.
3- The best multiplication medium for banana plants was semisolid MS medium supplemented with 5 mg/l BAP.
4- Subculturing the shoot tips on multiplication medium in four weeks intervals resulted in the formation of great number of shoots in six months. Use of this technique is recommended due to feasibility to obtain high number of plant materials with stable genetic background and good quality in short time, the essential need for mass micropropagation.
5- Some plants with visible phenotypic variations including rosy cluster of faint green and twisted leaves were detected under the influence of long term culture.
6- Optimum culture condition for root formation was obtained when excised microshoots were cultured on semisolid MS medium supplemented with 1 mg/l NAA.
7- Microshoots with well developed root system were acclimatized successfully in the growth room conditions, and the acclimatized plants showed normal growth in the field.
8- Sodium alginate (4%) and CaCl2 (75 mM) were successfully used to produce firm and clear uniform synseeds within 30 minutes.
9- The best banana synseed type was obtain when banana shoot tip was encapsulated in single layer synseed with synthetic endosperm containing 0.2% activated charcoal and 5 mg/l BAP.
10- Vertical orientation of encapsulated explants within the synthetic endosperm on conversion medium was recommended.
11- Gene expression of encapsulated shoot tip explants was influenced by the orientation of explant on conversion medium.
12- Synseed coat did not change the morphological shape or the size of synseed and it increased the conversion frequency and growth.
13- MS liquid medium supplemented with 1.5% sucrose and 2.5 mg/l BAP was the best medium for banana synseeds conservation.
14- Refrigerator temperature (4 °C) was the best temperature for banana synseeds conservation.
15- Banana synseed could be stored successfully for three months in lab. refrigerator.
16- Synseeds with synthetic endosperm containing activated charcoal without growth regulators expressed successful conversion where they showed synchronous development of shoot and root systems on semisolid MS medium supplemented with 1 mg/l NAA.
17- Synseeds with well developed shoot and root systems were successfully acclimatized to ex vitro conditions and the obtained plants showed continuous growth with normal growth.
18- Somaclonal variation can be efficiently controlled by decrease the number of subcultures, especially, when somaclonal variation is an undesirable phenomenon in micropropagation and production of synseed.
19- To control somaclonal variation via reduction of the number of subculture, synseeds were obtained through encapsulation of shoot tip explants in calcium alginate beads.
20- Comparison between the number of polypeptides detected in plants subjected to seven subcultures and those subjected to seventeen subcultures indicated that somaclonal variation increased with increase of number of subculture where 37 polypeptides were newly expressed.
21- RAPD analysis of genomic DNA of banana after 17 subcultures using 15 arbitrary selected oligonucleotide primers resulted in the resolution of 16 polymorphic bands. Analysis of RAPD products revealed some similarities between the patterns obtained by the tested lines.
22- from this study, it was concluded that protein studies only were not recommended to investigate somaclonal variation in banana but RAPD analysis can be successfully used. Detected variation using SDS-PAGE may be under genetic control.