Performance of micropropagation-induced off-type of East African highland banana (Musa AAA - East Africa)

Journal of Animal & Plant Sciences, 2011. Vol. 10, Issue 3: 1334-1338Tissue culture derived off-type plants with both good and poor field performance have been reported in banana and researchers have viewed the variants as a new source of genetic variability for crop improvement. In vitro micropropagation of East African highland banana (Musa - AAA East Africa) cv.’ Uganda’ resulted in high incidence of off-type plants. This study was conducted to evaluate the performance of the in vitro derived off-type banana in comparison with the in vitro micropropagation (MP) derived normal banana and conventionally propagated (CP) banana with no tissue culture history in its ancestry as controls. The evaluation of the off-type was carried out in 2005/2007 at Sokoine University of Agriculture based on number of days to plant flowering and fruit maturation, yield, fruit quality and shelf life. Results showed that the off-type banana produced significantly (P < 0.05) higher yield with bigger bunches and fruits of 52.2 t/ha, 21.1 kg per bunch and 125.3 g per fruit compared with 40.7 t/ha, 16.5 kg and 109.5 g of the MP derived normal banana and 45.7 t/ha, 18.5 kg and 118.3 g of the CP derived banana, respectively. The off-type fruits were significantly (P < 0.05) firmer with higher dry matter content of 12.4 kg/cm2 and 33.7 %. The firmness and dry matter content of the MP derived normal banana were 8.5 kg/cm2 and 20.0 %, and those of the CP derived banana were 8.9 kg/cm2 and 21.1 %, respectively. The off-type fruits had significantly (P < 0.05) longer shelf life of 17 days compared with 7.2 and 7.0 days of the MP and CP derived normal banana, respectively. However, the off-type banana was constrained by a significantly (P < 0.05) delayed flowering by one month and maturation by two months compared with the trueto- type banana. The observed agronomically desirable characters of the off-type banana underscore the potential of tissue culture technology as an alternative strategy for creation of genetic variability and improvement of East African highland banana