Biweekly changes in the in vitro shoot formation and growth pattern of pineapple (Ananas comosus L Merr) cv Smooth cayenne over 105 days of incubation on different hormone treatments

Abstract

BAP (6-benzylaminopurine) at 2.25 mg l-1 applied singly, in combination with indole acetic acid (IAA) at 0.175; 0.75; 1.75 mg l-1 and in combination with IAA at 1.75 mg l-1 plus gibbrellic acid (GA3) at 1.0 mg l-1 and BAP at 3.25 mg l-1 applied in combination with IAA at 1.75 and 3.75 mg l-1 were tested for their effect on the biweekly pattern of shoot formation (shoot per explant) and shoot growth (length and weight) of Smooth cayenne pineapple over 105 days of incubation. The highest shoot formation after 105 days of incubation were 31 shoots obtained in medium enriched with BAP at 2.25 mg l-1 plus IAA at 1.75 mg l-1 and the lowest were 10 shoots obtained in medium enriched with BAP at 3.25 mg l-1 plus IAA at 3.75 mg l-1. The shoot formation over 105 days took place in cycles of high and low pulses ranged from none to 11 shoots per each two weeks. Different hormone treatments may result in equall shoot formation but induced significant different pattern of shoot formation. Both of single application of BAP at 2.25 mg. l-1 and combination of BAP at 2.25 mg l-1 plus IAA at 0.75 mg l-1 resulted in equal formation of 25 shoots, but the shoot formation at each two weeks of the 105 days incubation were 1; 6; 3; 4; 8; 2; 0 and 1; 5; 2; 5; 10; 1; 0 shoots respectively. Similar, combination of BAP at 3.25 mg l-1 plus IAA 1.75 mg/l and combination of BAP at 2.25 mg l-1, IAA at 1.75 mg l-1 and GA 3 at 1.0 mg l-1 resulted in equal shoot formation (20 shoots) but different pattern. The total length and weight of shoots increased as the incubation increased and the pattern of the pulses of high and low gain per each two weeks in total length and total weight showed less fluctuation than that of the shoot formation pattern.

Effect of Sucrose Concentrations and Incubation Periods on in Vitro Rooting of Moris Pineapple (Ananas comosus)

“…Although the weight and length of the shoots used during rooting were not taken into consideration, found that heavy shoots of Spathiphyllum floribundum obtained during multiplication had a higher chance of survival during acclimatization. Hamad (2017c) found that the period of the highest increase in shoot weight and length of Smooth cayenne pineapple over each 15 days of 105 days of incubation varied depending on the hormone treatments and occurred after the shoots incubated for more than 45 days. Weight, length, and density of shoots at the beginning of the rooting stage may have great influence in its rooting response to sucrose and incubation period and proposed for future testing.…”