DEVELOPMENT OF APICAL SHOOTS AND ENDOGENOUS ABA CONCENTRATIONS IN PORANG TUBERS (AMORPHOPHALLUS MUELLERI BLUME) AFTER HARVEST

Abstract

This study aimed to analyze the development of apical shoots and the concentration of endogenous abscisic acid (ABA) in porang tubers after harvest. The development of apical shoots was prepared as a semi-permanent preparation which was observed using a microscope and ABA concentrations were analyzed using the High Performance Liquid Chromatogram (HPLC) method every two weeks. At 0 WAH, the meristem cells were differentiated and continued to grow until they reached 0.38±0.02 mm and formed shoot apical meristems (SAM) at 6 weeks after harvest (WAH) of 16.67%. At 12 WAH all tubers had formed SAM and shoots began to appear on the tuber surface. At the time when SAM had not yet formed, the concentration of endogenous ABA was high (433.07±39.26 ng/g), but when SA M was formed and the meristem height reached 12.52±4.90 mm the concentration decreased to 102.90±22.19 ng/g (20 WAH). The emergence of shoots and a decrease in the concentration of endogenous ABA at 12 WAH indicated that the dormancy period had ended. Based on this, the age of the best tubers is not more than 10 WAH. Over 10 WAH, tuber quality will decrease due to biochemical changes, so that the nutrient content, especially glucomannan, is reduced, therefore it is not ideal as industrial material.