Changes in the initiation of climacteric ethylene in harvested avocado fruits during their development

Climacteric ethylene production was found to start close to the pedicel, at the proximal part of “Hass” avocado (Persea americana Mill.) fruits in the immature stages, and at the distal part of mature fruits. The start of ethylene production corresponded closely to the softening patterns in immature and mature fruits. The possibility is discussed that this phenomenon is a result of differential levels of factors which inhibit ethylene production, arriving from leaves and regulated by the sink properties of the growing seed.