|Title:||Micropropagation of two apple (Malus domestica Borkh) varieties from shoot tip explants|
|Keywords:||Ethiopia;Holetta Agricultural Research Center;Plant growth regulators;plantlet|
|Abstract:||Malus x domestica Borkh is a perennial pomaceous fruit tree belonging to the family Rosaceae and sub-family Maloideae. Although the plant is generally found in the northern temperate zones of North America, Europe, Asia Minor and Asia, species within the genus have wide geographical distribution. Apple fruit has been considered to have high health benefits. Most of the species within the genus intercross. Since self-incompatibility is common, apples produced from seed are mostly interspecific hybrids. Therefore, it is difficult to produce true-to-type cultivars from seeds. The objectives of this study, therefore, were to develop micropropagation protocol for two apple (Malus domestica Borkh) varieties, MM106 and Anna, which are highly adapted for environmental conditions of Ethiopian highlands, using shoot tip explants and assessing the in vitro multiplication potential of this plant up to the fifth sub-culturing stage on MS medium. From the seven combinations of BAP and IBA in full MS medium was used for culture initiation, the servival percentages of the cultured shoots with healthy morphology were 96.7 for MM106 in 1.0 mg/l BAP and 0.1 mg/l IBA medium composition and 93.3 for Anna in 1.5 mg/l BAP and 0.1 mg/l IBA combinations. Among the different treatment combinations used for multiplication, 6.33 ± 0.50 and 4.93 ± 0.42 mean number of shoots were obtained in 1.5 and 2.0 mg/l BAP combined with 0.5 mg/l GA3 and 0.01 mg/l IBA for MM106 and Anna varieties respectively. Sub-culturing stage has also significantly affected multiplication potential of the two varieties. The maximum shoot number was obtained on the 5th (8.70 ± 2.77 mean number of shoots) and 2nd (7.63 ± 0.59 mean number of shoots) sub-culturing stages for MM106 and Anna varieties on the above respective multiplication media compositions. The two auxins, IBA or IAA, with or without activated charcoal (AC) showed significant difference in the number and length of roots of the two varieties. The maximum number of roots was 5.7 ± 0.69 for MM106 and 6.25 ± 0.50 for Anna in media supplemented with 1.0 and 2.0 mg/l IAA combined with AC, respectively. Relatively longer length roots (in cm) were obtained in 1.5 mg/l IBA without AC, 4.55 ± 1.40, for MM106 and 1.0 mg/l IBA with AC, 6.00 ± 0.95, for the Anna varieties. Finally, the survival rate of the acclimatized plantlets in the glasshouse was 91.4% and 65.7% for MM106 and Anna varieties, respectively.|
|Description:||A Thesis Submitted to the School of Graduate Studies of Addis Ababa University in Partial Fulfillment of the Requirements for the Degree of Master of Science in Biotechnology|
|Appears in Collections:||Thesis - Biology|
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