Effect of NAA and BAP concentrations on rambutan growth (Nephelium lappaceum L.) in Vitro

Rambutan fruit (Nephelium lappaceum L.) is a popular fruit in the ASEAN (Association of Southest Asian Nations) region. Rambutan is a tropical fruit plant that is much favored by people both at home and abroad. Rambutan fruit is much loved and in demand, this is because it has a delicious, sweet taste and has a fairly high nutritional value. Apart from being consumed fresh, rambutan fruit also has a lot of benefits. Demand for rambutan commodities continues to increase but is not matched in terms of production which tends to decline every year. The cultivation of rambutan has not been carried out intensively so that the production and quality are not optimal. Therefore, it is necessary to breed rambutan through the application of in vitro culture to overcome this problem. The application of biotechnology through tissue culture is believed to be able to provide seed mass, uniform and throughout the year, so that the demand for rambutan commodities can be met. This study aims to examine the effect of growth regulators, namely BAP and NAA, on the growth and development of rambutan lateral shoot explants planted on Woody Plant Medium (WPM) in vitro using several varieties. This research was conducted from August 2020 to April 2021 in the Laboratory of Plant Physiology and Biotechnology, Faculty of Agriculture, Sebelas Maret University. The prime purpose of this research is to figure out the best growing regulatory substances and varieties in the growth of rambutan plants in vitro. This study used a completely Randomized Design with two treatment. Varieties consisting of rapiah, binjai, ace was the first factor, and the growth regulator type consists of four levels: 0 ppm, NAA 0.5 ppm, BAP 4 ppm, NAA 0.5 ppm + BAP 4 ppm was the second factor. The study showed that the combination treatment of NAA 0.5 ppm + BAP 4 ppm was able to produce an average when the fastest shoots appeared (13.33 DAP), the average when the most rapid leaves appeared (20.67 DAP), with the leaves’ average number (4 leaves), the fastest roots’ average number (21 DAP), the average number of roots (3 roots), and the longest average root is 3.67 cm in the binjai variety.