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Breadfruit. A Tale of Two Domesticates?. Outline. Artocarpus altilus Biology and Distribution The Relatives Methods of Determination Origins…. Artocarpus altilus. Moraceae Tree Crop Variety of uses Grown for infructescence rather than vegetative storage structures Staple of Oceania
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Breadfruit A Tale of Two Domesticates?
Outline • Artocarpus altilus • Biology and Distribution • The Relatives • Methods of Determination • Origins…
Artocarpus altilus • Moraceae • Tree Crop • Variety of uses • Grown for infructescence rather than vegetative storage structures • Staple of Oceania • 2 “generalized” cultivars • Seedless • Few-->Many Seeded • High productivity • Seasonal • Mmm…just like potatoes A. altilus (Ken Sytsma)
Breadfruit Biology Monoecious Pollen quantity varies Parthenocarpic fruit development in seedless Pollination mechanism unknown http://www.biologie.uni-hamburg.de/b-online/library/webb/BOT410/Angiosperm/FlowersFruitsSeedsLabCombo.htm
Distribution http://www.hawaii.edu/powerkills/WF1.WORLD.JPG
Diversity • Fruiting Season • Fruit Shape • Fruit Color & Texture • Infructescence surfaces • Flavor • Sections • Leaves • Seeds • SEMs of trichomes • Infertility • 2n=3x=˜84; 2n=2x=56 http://geo.cbs.umn.edu/~nyree/breadfruit_page.html
Ranges of Close Relatives A. mariannensis A. camansi Fig 2. Zerega et al. (2005)
Methods of Determination • Morphology, ITS and trnL-F region • AFLPs • Isozymes Fig 10.2
AFLP Data Fig. 10.4
Fig. 4 NJ Tree Fig. 3 Zerega et al. (2005)
AFLP (cont.) Fig. 3 Zerega et al. (2004) Fig. 10.5
MDH isozyme phenotypes & AFLP markers Fig. 10.3
What trends are seen in the data? • Melansian and Polynesian breadfruit cultivars are more closely related to A. camari • Micronesian cultivars are closely related to Polynesian and Melanesian A. camansi-derived breadfruit and to A. mariannensis • Micronesia has the greatest genetic diversity; however, Polynesia cultivars are most genetically differentiated • Dependent on mode of reproduction and human selection
Analysis of Molecular Variance Based on AFLP Individual Islands Serve as Repositories for Genetic Diversity
Melanesia and Polynesia • Assumption: • High genetic variability=Region of Origin • Colonization during Pleistocene (40,000 yrs ago), dispersal of A. camansi to “near” Oceania, and human selection • Lapita cultural complex shifted to vegetative propagation for longer voyages (4,000 yrs ago)
Micronesia • Triploid A. camansi-derived “E Polyn” • Hybrid cultivars • Fertile and sterile diploids and sterile triploids • Human involvement a must as ranges of A. camansi and A. mariannensis do not overlap • Settled from multiple directions many times…
Captain Bligh • Transport Breadfruit to the Caribbean from Tahiti on the HMS Bounty • The “No Paradise” rule • Mutiny • Navigated 3600 nautical miles using a sextant and a pocket watch • Pitcairn Island • Returned and took 347 breadfruit plants to St. Vincent and Jamaica on February 5th, 1793