Sir

Your News Feature “A dying breed” (Nature 421, 568–570; 2003) highlights the threat to commercial banana plantations from a strain of Panama disease. Scare stories predicting the imminent end of the banana if this fungal pathogen spreads to Latin America have been blown up out of all proportion in the media (see, for example, New Scientist 26–29, 18 January 2003). Contrary to what has been written, the Panama pathogen with the ability to kill Cavendish (the main commercial subgroup of banana) in the tropics is found only in parts of a few countries, notably Malaysia and Indonesia.

Controls on the international movement of banana planting material should prevent this particular type of Panama from rapidly expanding its distribution. Even if this pathogen strain appears in plantations in Latin America, strict quarantine measures should limit its effects. Neither the export banana, nor any other banana, is in danger of disappearing just yet.

Because of the sterility of Cavendish cultivars, genetic manipulation is seen as the answer to disease problems that afflict this important crop. Although Cavendish is sterile, to label all bananas “sterile mutants” is an unkind exaggeration. Many clones are fertile and have been used in conventional breeding programmes.

New bananas have been successfully created by crossing synthetic diploids (derived from wild species with resistance to disease and pests) with cultivars in need of improvement. Much work has been undertaken at the Honduran Agricultural Research Foundation (FHIA) in the past, and its hybrids have found niches in various countries around the world. Many thousands are grown in Cuba, where chemical disease control is an unaffordable extravagance.

Certainly, the goal of breeding a disease-resistant replacement for Cavendish, the banana commonly seen in supermarkets, by conventional means has been elusive. However, the development of a new export banana is by no means impossible. The late Phil Rowe hoped to achieve this at FHIA by crossing fertile dwarf variants of 'Gros Michel', the old cultivar of the trades, with his improved diploids. More funding, which is sadly lacking, could still help his dream to be realized.

As reported with other crops, limited funds for banana improvement seem to have been channelled into genomic and genetic transformation work. If consumer objections to genetically modified food can be overcome, this research may have long-term benefits. However, we need to keep all our options open and also support conventional breeding methods.