FIELD PERFORMANCE OF TRANSGENIC TOMATO WITH REDUCED PECTIN METHYLESTERASE ACTIVITY

Transgenic 'Rutgers' 37-81(boolean AND) tomato (Lycopersicon esculentu m Mill.) homozygous for a pectin methylesterase (PME) antisense gene, which lowers PME activity and increases levels of soluble solids, was compared to azygous (a segregating line of 37-81(boolean AND) with 0 c opies of the introduced gene) and wild-type 'Rutgers' in the field dur ing Summer 1992 and 1993 to determine the effects of the introduced PM E antisense gene on tomato plant growth, fruit set, fruit yield, and f ruit processing attributes, Fresh and dry weight accumulation in trans genic plants was similar to wild-type 'Rutgers' and azygous 37-81(bool ean AND) lines during 1992 and 1993, indicating that the introduced PM E antisense gene did not affect biomass accumulation, Transgenic plant s showed an increase in fruit number and yield in 1992 compared to wil d-type 'Rutgers' and azygous 37-81(boolean AND), but no differences we re observed among the three genotypes in 1993. Average fruit weight di d not show significant differences among the three genotypes in 1992, but was lower in azygous and transgenic plants than wildtype plants in 1993. Transgenic fruit had higher soluble and total solids and higher pH than control fruit, but shelf life was somewhat shorter in transge nic fruit, Overall, these data indicate that introduction of the PME a ntisense gene, which improves the processing quality of tomatoes, does not adversely affect fruit yield or vegetative growth of plants.