Site author Richard Steane
The BioTopics website gives access to interactive resource material, developed to support the learning and teaching of Biology at a variety of levels.
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Site author Richard Steane
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The BioTopics website gives access to interactive resource material, developed to support the learning and teaching of Biology at a variety of levels.
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Most sweet bananas grown today are from a single variety - " Cavendish" - produced as a result of asexual reproduction, not from seeds.
In order to meet the world demand for this fruit, banana plants are grown in several tropical countries, many of which are islands. In Africa, different species (some called plantains) are used, and prepared to be eaten in different ways. In these places, they are the main crops (an example of monoculture). The crop may be damaged by weather conditions - tornadoes are a constant menace - or as a result of diseases - especially fungus diseases. |
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Just like the Irish potato famine, there have been several instances of banana crop failure due to fungus disease. One fungus disease ("Panama disease" caused by Fusarium oxysporum) has been through several stages, widespread crop damage being prevented each time by use of fungicides and changing banana varieties grown. Another disease ("Black Sigatoka" caused by Mycosphaerella fijiensis) is a possible threat in the future.
In fact the way that bananas are propagated from shoots at the base of the tree may spread fungal infections as fungal spores may be in the small amounts of soil transferred at the same time. This soil transfer may be avoided if shoots are used to produce a bulk of clean new plants by micropropagation, which also relies on asexual reproduction. Would these plants produced by micropropagation be resistant to the fungal diseases? > No - they are genetically identical to the parent plant, unless resistance genes are obtained from another variety or species - a good candidate for genetic manipulation. |
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