| Popis: |
Inadequacy of planting materials is limiting the distribution of three high-β-carotene (pro-vitamin A) cassava varieties released in Nigeria to increase public vitamin A intake. However, studies have established the suitability of in vitro shoot culture for mass propagation of elite crop varieties for quick distribution to farmers. We investigated multiple shoot induction from axillary bud of three β-carotene enriched cassava varieties using BAP and assessed the genetic stability of the regenerated plants to establish mass propagation system. Multiple shoots were induced from BAP-enlarged axillary bud on basal medium supplemented with 10 mg/l BAP. Shootbuds were elongated on basal medium supplemented with 1.0 mg/l BAP and 10.0 IBA mg/l. Genetic stability of regenerated plants was assessed byeight RAPD markers. There were significant (P < 0.05) differences in survival of isolated axillary bud, shootbud formation, survival of shootbud, regenerated shoots, root formation and survived regenerated plants among cassava varieties. The order of shootbud formation among the cassava varieties was UMUCASS 37 > UMUCASS 36 >TMS 30555 > UMUCASS 38. The best (83.4%) shoot regeneration was recorded in TMS 30572 and lowest (47.8%) in UMUCASS 37, however, UMUCASS 36 recorded the best (98.5%) survival of regenerated shoot after hardening. Eight RAPD primers produced 56 bands, ranging from 200 to 3000 bp in size. RAPD analysis showed a uniform profile among regenerants and between mother plant and regenerants. The study concluded that multiple shoot formation could be induced in pro-vitamin A cassava varieties using BAP from axillary bud with no genetic infidelity of the regenerants. |
