A RECENT MODEL OF TOMATO FRUIT EXPANSION

A model of the tomato fruit expansion and comparisons to literature data, which have been published (Ann. Bot. 1993, 72: 63–72, 1994, 73: 75–82 and 1995, 75: 469–476) are presented here. In this model, the transfer pathways into the fruit from the fruit pedoncule towards water storage sites are compared to permeable tubes in which the water transfer rate is ruled according to the law of viscous liquid in porous material. Therefore, the water import rate depends in particular on fruit size, on the water potential at fruit pedicel level, on the osmotic potential in fruit and on fruit temperature. Moreover, according to this flow model, the imported dry matter concentration is predicted to be increased when the water velocity in the transfer pathways is increased. Various literature data agree well with this model which should be able to contribute to better understanding of fruit size and fruit dry matter content.