Pengaruh Modifikasi KH2PO4, NH4NO3 dan Sukrosa terhadap Pertumbuhan Tunas serta Pembentukan Umbi Mikro Taka (Tacca leontopetaloides) secara In vitro

Abstract

ABSTRACT Polynesian arrowroot (Tacca leontopetaloides (L.) Kuntze), which is one of the bulbous herbaceous plants, have high nutritional value. Modification of macro nutrients by reducing nitrogen content and increasing phosphorus on the medium gave affects on shoot growth and initiated micro tuber formation on in vitro cultures. The aim of this research was to determine the effect of modified macro nutrients in combination with the increase in sucrose concentrations on shoot growth and micro tuber formation of T. leontopetaloides. The experimental design was factorial completely randomized design.The factors tested were modifications of MS macro nutrients that were. M1 (170 mg/l KH2PO4 and 1650 mg/l NH4NO3; normal, control treatment); M2 (340 mg/l KH2PO4 and 825 mg/l NH4NO3); and M3 (680 mg/l KH2PO4 and 412.5 mg/l NH4NO3 in combination with 30 (S1) (control treatment), 40 (S2), 50 (S3) and 60 g/l of sucrose (S4). The variables tested were shoot height, number of leaves, number of roots and number of micro tuber which were observed weekly at 0-8 weeks after culturing. The results showed that the modification of macro nutrient in combination with sucrose concentration had significant effect on shoot height, number of leaves and number of roots but not significant on the number of tubers. The highest shoots were found in M1S3 treatment, the highest number of leaves was in M1S1 and M1S3 treatment and the highest number of roots was in M1S4 treatment. The number of tubers not significantly different between the treatments tested. Keywords: in vitro, KH2PO4, microtuber, NH4NO3, sucrose, Tacca leontopetaloides