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Reproductive Biology
- Chapter Authors : Fortescue, J.A.; Turner, D.W.
- Document type : Book section
- Year of publication : 2011
- Book title : Banana Breeding: Progress and Challenges
- Publisher(s) : CRC Press
- Place of publication : Boca Raton, USA
- ISBN : 978-1-4398-0017-1
- Pages : 145-180
- Language(s) : English
- Abstract : The inflorescence of most Musa species and cultivars is monoecious. The female flowers are first formed and precede the male flowers in anthesis. Flowers are formed following the normal Asterad pattern and are similar in the wild-seeded species and the edible, sterile and parthenocarpic landraces, at least up until anthesis. Beyond this, numerous events combine to minimize seed development in cultivars. While many of these are known. the importance of each in any situation is uncertain. There is a need to know more about why so few seeds are produced, when there are records of high seed production. even in cultivated genotypes. Several factors, such as receptivity of the female organs, pollen tube growth. ovary position within the bunch, season of pollination, time of day, and location contribute to seed production in banana. There is also an interaction between environment and fertility of female and male components. These factors can be managed to manipulate seed production so that the immediate objective of crosses (such as production of triploids or tetraploids) can be met. The clumped nature of the plant means that crossing in the wild-seeded species can be achieved between inflorescences within the one clump, and outbreeding can occur if other clumps of bananas are nearby. Heterozygosity is high among the edible diploids. which have been dispersed by people. but somewhat less among the seeded wild species that tend to be geographically isolated, one species from another. Pollen production varies considerably between genotypes and locations, as does its viability. There is not necessarily a correlation between the viability of pollen and the number of seeds produced by receptive flowers. The production of 2n pollen is used to increase the production of tetraploids in breeding schemes and it is believed that this was the process that produced the triploid landraces used widely today. Hybridization lies at the heart of breeding. There has been considerable effort to discover the likely route by which the diploid and triploid landraces were produced. This opens the possibility of determining which crosses might best be used to not only incorporate disease or pest resistance in progeny but to also provide new cultivars that retain the desirable qualities that people selected in the first place. Selection of bananas for edibility has been a high priority for people for thousands of years and the primary aim was to select plants with fruit that were seedless. Breeding bananas for resistance to disease. tolerance of edaphic and environmental constraints, and desirable postharvest qualities is a more recent activity spread over several decades. Breeding requires seed. Once seed are produced, few of them germinate and so seed production and germination are bottlenecks in banana breeding. Seeds of the wild bananas germinate readily when they are fresh and as they dry they enter a functional physical dormancy that can be broken by alternating temperatures when the seed is hydrated. Many banana seeds do not germinate because they do not contain embryos. Many embryos are not viable, further reducing germination. Viable embryos can be excised and cultured aseptically to produce plants for selection. In recent decades, knowledge of the reproductive biology of plants has progressed, but work on banana has been slow. There is a need to reengage research on reproductive biology in Musaceae, bringing to bear the new knowledge gained on "model plants" so that new, disease-resistant cultivars can contribute to sustaining the world's population.
- Keywords :
FLOWERING;
SEEDS;
POLLINATION;
SEXUAL REPRODUCTION;
REVIEW
- Open access : No
- Document on publisher's site : View article on publisher's site
- Musalit document ID : IN160562
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