|Lopez-sese, Ana Isabel|
Submitted to: Genetic Resources and Crop Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/15/2000
Publication Date: N/A
Citation: N/A Interpretive Summary: Bottle gourd is an American crop of ancient origin. The mature fruit has been fashioned into containers, utensils, musical instruments, birdhouses, floats, pipes and masks. Archaeological (ancient origin) remains suggest the independent use and possible cultivation of bottle gourd by 9,000-15,000 B.P. (before present) in the Americas 6,000-10,000 B.P. in eastern Asia, and 4,000-5,000 B.P. in Africa. Because of these early dates, this species is important to discussions concerning where, how and why plants were originally domesticated (brought into cultivation). Although the origin of bottle gourd is likely Africa, several questions exist concerning the evolutionary history of this species. Therefore, a study was designed to clarify this species' ancient biogeography (its original dispersal from Africa), and the differences that exist between various gourd populations worldwide. We used DNA analysis and found that: 1) southern African wild varieties represent a divergent linkage from which several modern cultivars have been selected, 2) new world (Americas) varieties are distinct and primarily of African origin, but are also similar to Asian varieties in some ways and; 3) commercial cultivars are diverse in their geographic origins. These finding will allow for a better scientific understanding of the domestication of this species. It will also provide plant breeders with heretofore unavailable information of cultivar differences.
Technical Abstract: Bottle gourd (Lagenaria siceraria) is an African crop with an ancient pantropical distribution. Morphological analyses and archaeological evidence suggest the oceanic dispersals of wild bottle gourd fruits from Africa to Asia and the Americas by 10,000-15,000 B.P., followed by independent domestications on those continents. There have been questions concerning the origins of Asian landraces, including whether or not there was early germplasm exchange between Asia and the New World. There are also concerns regarding the origins and circumscriptions of commercial cultivars. To clarify the evolutionary histories of bottle gourd landraces and cultivars, 64 random amplified polymorphic DNA (RAPD) markers representing 30 primers were examined in 31 landraces and 43 cultivar accessions of L. siceraria, as well as in a wild relative, L. sphaerica. Data revealed the following: 1) southern African germplasm represents a divergent lineage from which several cultivars have been selected; 2) New World germplasm is distinct and primarily of African origin(s), but possesses Asian affinities as well; 3) landraces from Papua New Guinea are not related to New World germplasm, as previously hypothesized; 4) commercial cultivars are diverse in their geographic origins and genetic compositions; and 5) the integrity and circumscriptions of some cultivars have been confounded by production practices allowing gene flow among cultivars.