ISHS Acta Horticulturae 461: International Symposium on Biotechnology of Tropical and Subtropical Species Part 2
THE BIOTECHNOLOGY CASE HISTORY FOR MUSA |
| Authors: | D.R. Vuylsteke, J.H. Crouch, A. Pellegrineschi, G. Thottappilly |
| Keywords: | banana, genetic improvement, micropropagation, molecular markers, plantain |
| Abstract:
Banana and plantain (Musa spp. L.) is a major tropical food crop and world commodity. Being a polyploid and vegetatively-propagated crop, its genetic improvement by conventional hybridisation is complex and difficult, yet not impossible. Simple tissue culture techniques, such as shoot-tip and embryo culture, are well developed and have greatly enhanced Musa germplasm handling and breeding. Plant regeneration by somatic embryogenesis is used to recover transgenic plants from single cells transformed by Agrobacterium or biolistic techniques for fungal and viral disease resistance. The potential of somaclonal variation as a source of novel and useful variability is limited, but it may be used as a secondary tool in Musa improvement. Molecular genetic techniques are being applied for improving the efficiency of Musa breeding. RFLPs appear to have limited application due to the low frequency of detected polymorphisms. The RAPD technique holds great promise for genome analysis. It detects high levels of polymorphism, yet still suffers from a number of practical drawbacks. Microsatellites are used to study genetic behaviour and structure in Musa, for fingerprinting hybrids, and to develop marker-assisted breeding systems. Candidate markers for such complex and important characters as parthenocarpy, earliness and regulated suckering are being tested. PCR primers have also been developed for virus diagnostics, already providing a specific and sensitive method to detect banana streak virus among in vitro plants. Reliable diagnostic protocols are increasingly needed for safe international movement of germplasm. Musa improvement requires a holistic approach to produce better cultivars. Hence, it is advocated that multidisciplinary public Musa breeding programmes should be central to any improvement effort. Such programmes will benefit from three biotechnologies that are clearly valuable in Musa breeding - tissue culture, diagnostics and molecular markers. Realistic, well defined targets for genetic engineering are occasionally warranted for inclusion within innovative breeding programmes. | |
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