Abstract:
In vivo macropropagation either alone or in combination with benzlyamimopurine (BAP) is an alternative simple technique for banana multiplication but has not been applied to recalcitrant plantain such as cv. “Itoke Sege”. This study was conducted to determine the effect of BAP concentration on in vivo multiplication and genetic stability among in vivo derived regenerants of plantain cv. „Itoke sege‟. An experiment was laid out in RCBD with four treatments each replicated three times. The treatments consisted of four BAP concentrations (1.5, 3.0, 6.0 mg/l and untreated control). Data were collected on number of days to first shoot emergence, number of shoots per corm, shoot size and morphological and genetic stability of in vivo derived shoots. Morphological stability was assessed using banana morphotaxonomic descriptors while genetic instability was assessed based on analysis of 2C nuclear DNA content of in vivo derived suckers. Results showed that BAP concentration at 1.5 mg/l significantly (P ≤ 0.05) enhanced first the shoot emergence at 15.78 days followed by BAP at 3.0, 6.0 mg/l and untreated control with 25.18, 28.39 and 36.43 days, respectively. Moreover, BAP concentration at 1.5 mg/l significantly (P < 0.05) produced the largest number of suckers of 17.11 suckers per corm followed by untreated control and BAP concentration at 3.0 and 6.0 mg/l and with 15.23, 13.08 and 12.96 suckers per corm, respectively. Similarly, BAP at 1.5 mg /l and untreated control significantly (P ≤ 0.05) showed the lowest frequencies of off-types with 10.89 and 10.23 % compared to BAP at 3.0 and 6.0 mg/l with 12.08 and 12.86 % of off-types, respectively. However, ploidy analysis revealed that the off-type and normal banana suckers had significantly (P ≤ 0.05) equal 2C nuclear content and ploidy level. The findings of this research provide evidence for the use of in vivo macropropagation coupled with BAP at 1.5 mg L-1 as an alternative technology for rapid production of planting materials of recalcitrant plantain varieties.
