Economic Botany: Evolution of Cultivated Plants
Rapoport, Hava .
Modifications of fruit cell and tissue development patterns in the domestication of the olive.
IN selecting for high productivity and desirable fruit types, mankind has also selected for the developmental processes by which those fruit types form. In the olive (Olea europaea L.) fruit, a drupe, selection has aimed for a large final product with high oil content in the fruit mesocarp and a relatively small stony endocarp. We know little, however, about what developmental processes contribute to producing that final product, and to what degree the present patterns are required or might be modified, still maintaining or even improving fruit production. In order to explore these issues, fruit growth, relative growth and partitioning between the mesocarp and endocarp, and the cellular components of mesocarp expansion were compared between wild olive populations from four different Spanish provinces and cultivated varieties. Fruit fresh weight for cultivars was ten to 20 times greater than for the wild olives. That size increase was mainly due to the mesocarp, in which fresh weight increased 20-30 times, while endocarp fresh weight increased only two to four times, resulting as well in a tenfold increase in the horticultural flesh-to-stone index. The greater mesocarp expansion of cultivated fruits was based mainly on a ten-fold increase in cell number, while cell size, measured as cross-sectional area, only doubled. The results are discussed in terms of the complex interaction between mesocarp and endocarp, which is both dependent and competitive in nature, the potential and relative contributions of cell division and enlargement to fruit growth, and how domestication has exploited these processes.
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1 - Inst Agric Sostenible C.S.I.C., Apartado 4084, Cordoba, E-14080, Spain
Presentation Type: Oral Paper:Papers for Topics
Location: 303/Bell Memorial Union
Date: Tuesday, August 1st, 2006
Time: 8:45 AM