Reactions of Musa Genotypes to Drought Stress

African Crop Science Journal, Vol. 7. No. 4, pp. 333-339, 1999 Reactions of Musa Genotypes to Drought Stress Code Number: CS99023 ABSTRACT: Experiments were conducted at Makerere University Research Institute Kabanyolo (MUARIK), Uganda to identify the factors enabling the plant resistance and adaptability to drought stress in banana. Six banana cultivars (Nfuuka (AAA-EA); Sukalindizi (AB); French Plantain (AAB); Gros Michel (AAA); Lep Chang Kut (BBB) and FHIA-02 (AAAA) were subjected to 4.5 weeks of water stress during which soil moisture tension rose to over 400 mbar in potted experiments. Soil moisture tension of >400 (mbar) significantly (P<0.05) reduced growth, green leaf area, photosynthetic rate, stomatal conductance and sub-stomatal CO2 concentration. Cultivar Sukalindizi recorded significantly (P<0.05) lower transpiration rate and sub-stomatal CO2 but high assimilation rate indicating adaptability and resistance to drought stress, while cultivar Lep Chang Kut showed significantly (P<0.05) high transpiration rate and sub-stomatal CO2 concentration but low assimilation rate, leaf water retention capacity (44.5%) and stomatal conductance indicating its sensitivity to drought stress. The results from Lep Chang Kut were contrary to the concept that Musa balbisiana containing genomes have drought stress resistance. Gros Michel (AAA) and FHIA-02 (AAAA) exhibited stress resistance by retaining a high green leaf area (Y= -60.12x + 3261.5 and Y= -59.83x + 2558, respectively) and intermediate leaf water retention capacity (50.7 and 55.3%, respectively). Cultivar French Plantain (AAB) also exhibited intermediate moisture retention capacities (57.9%) indicating intermediate sensitivity to drought stress. The East African Highland banana Nfuuka had the lowest leaf water retention capacity (28.0%), indicating its sensitivity to drought stress. KEYWORDS: Banana, drought stress resistance, green leaf area, growth responses, stomatal conductance, transpiration rate Copyright 1999, African Crop Science Societ