The Role of Cellulase and Polygalacturonase in Abscission of Young and Mature Shamouti Orange Fruits

摘要: During the first eight weeks after setting young citrus fruits gradually lose their ability to abscise at abscission zone between stem and pedicel; in older than occurs calyx area. The activity of cellulase polygalacturonase two zones was markedly increased before during abscission, localized mainly zone. Ethylene accelerated increase enzymic an 8- 10-h lag period; 2,4-D delayed when applied 24 h excision. this period also partly suppressed enhancing effect ethylene. Early application cyclo-heximide inhibited formation enzymes thus a certain extent. Although there are some indications that relationship is complex one, data presented indicate play significant role various developmental stages. Both act almost simultaneously equally controlled by ethylene 2,4-D.