CHANGES IN INDOLE-3-ACETIC-ACID AND ABSCISIC-ACID LEVELS DURING TOMATO (LYCOPERSICON-ESCULENTUM MILL) FRUIT-DEVELOPMENT AND RIPENING

Changes in the levels of indole-3-acetic acid (IAA) and abscisic acid (ABA) in tomato (Lycopersicon esculentum Mill.) fruit pericarp tissue during development through ripening were measured by GC-SIM-MS using d3-ABA and C-13(6)-IAA internal standards. In the two cultivars of field-grown tomatoes analyzed, the highest IAA levels (8-24) ng/g fw) were found at the earliest stage of development (7 days after anthesis) followed by a rapid decline in levels of the hormone. ABA levels of 40-60 ng/g fw were found at the earliest stages of development followed by a decline in levels until ripening occurred when elevated ABA levels (125 ng/g fw) were measured.