Effect of Explants Length and Segmentation and Separated and Cluster of Shoots on the in vitro Shoot Formation and Growth of Pineapple (Ananas comosus L. Merr.)

Abstract

Two experiments were conducted. In one, multiple shoots complex from Smooth cayenne pineapple stock cultures were cut into cluster of two, three, four shoots and were also separated into individual shoots of different length 5, 10, 15, 20 and 25 mm long and cultured on agar solidified MS medium enriched with benzylaminopurine (BAP) at 2.23 mg/l. In the other one, 25 mm long shoots were cut longitudinally into halves and quarters and cultured at density of one explant and 15 mm long shoots were cultured intact at density of one, two, three and four explants per culture. Longer (25 mm) intact and halved explants produced the highest (10 shoots) while 5 and 10 mm long explants resulted in lowest (6 shoots) and 15 and 20 mm long explants resulted in an intermediate (8 shoots) shoot formation. Shoot formation whether the explants were cultured as separated intact or as cluster of shoots decreased from 10 to 4 shoots per explant as the density increased from one to four. Shoot length was not affected by using of separated intact explants of different length. However, increasing the explants density increased the shoots length particularly when cluster rather than separated shoot were used as explants.