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Banana (Musa spp.), an important staple food in the tropical and subtropical regions, is highly susceptible to drought. Developing drought-tolerant bananas using available germplasm offers a long-term solution to mitigate drought effects. The East and Central Africa Banana Germplasm Collection in Uganda contains genetically diverse genotypes whose potential for drought tolerance breeding is yet to be established. This study aimed to determine the response of 14 Musa spp. genotypes to drought stress using phenotypic and physiological traits in order to select promising genotypes for use in breeding. Two genotypes with a known reaction to water deficit conditions were included as local checks. Three-month-old tissue culture-derived plantlets were completely deprived of water for four weeks while control plants were regularly irrigated back to field capacity, and both sets maintained under screen-house conditions. Drought stress resulted in significant reductions in plant height, total leaf area, number of leaf cigars and functional leaves, total dry matter, chlorophyll and relative water content. Water use efficiency (WUE) of 12 genotypes increased under stress conditions. Stomatal conductance was affected by the genotype-porometer reading time interaction. Genotype "ITC.0987" was the most tolerant, considering that moisture stress had the least effect on its above-ground growth. Among the improved diploids, "TMB2x9722-1" had the least total dry matter reduction and highest WUE, while "TMB2x9172" showed the least decrease in relative water content and highest root-shoot ratio increase under stress. Thus, "ITC.0987", "TMB2x9722-1" and "TMB2x9172" are essential drought-tolerant candidates that may be utilized in breeding. [ABSTRACT FROM AUTHOR]

Drought is a major abiotic stress affecting banana production worldwide, leading to yield losses of up to 65%. Consequently, numerous efforts to understand and mitigate drought effects that include developing tolerant crop varieties are ongoing in several banana breeding programmes. The breeding efforts, however, have been greatly slowed down by inherent banana problems (polyploidy and male or female sterility) and complexity of drought tolerance (reportedly controlled by several genes). This review summarizes the pertinent research findings on water requirements of banana for its proper growth and productivity, symptoms of drought‐sensitive varieties and field management strategies to cope with drought stress. The coping strategies deployed by resistant cultivars include high assimilation rates and water retention capacity as well as minor losses in leaf area and gaseous exchange. Reduced bunch weight, leaf chlorosis, wilting and strangled birth are underlined to be directly associated with drought susceptibility. Integration of conventional, molecular breeding and biotechnological tools as well as exploitation of the existing banana genetic diversity presents a huge opportunity for successful banana improvement. [ABSTRACT FROM AUTHOR]

In the densely populated East African highlands (EAH), banana is a major staple food. In the last decade, serious yield declines were observed caused by soil fertility depletion and increased pressure of pests and diseases. Arbuscular mycorrhizal (AM) fungi form symbiosis with plant roots improving nutrients and water absorption, and protecting plants against a number of biotic (e.g. root pathogens) and abiotic (e.g. drought) stresses. Use of crop genetic diversity could be an appropriate option to improve production by using highly mycotrophic genotypes. This study assessed AM fungal root colonization of 18 banana genotypes across 6 locations in East Africa (Rwanda, Burundi, Kenya, DR Congo, Uganda and Tanzania). Soil and root sampling was carried out on each genotype. Data were collected on root colonization frequency and intensity, soil pH, cation exchange capacity and mineral nutrients. The results suggested that (i) high receptivity but low banana genotype specificity to the AM fungi exist among the five genotypes present in all the study sites; (ii) high variability in root colonization exists within the site among a wide range of Musa genotypes: from AA, AAA to AAB, ABB and tetraploids. [ABSTRACT FROM AUTHOR]