Effect of Plant Growth Regulators, Basal Media Strength and Carbon Sources on Hylocereus Costaricensis (Red Dragon Fruit) Seed Germination

Abstract

Hylocereus costaricensis, commonly known as red dragon fruit or 'pitaya,' is famous for its purple-red flesh. It has achieved international recognition as an ornamental plant and secondly as a commercial fruit crop. Containing high level of vitamin C and antioxidants like betalans, hydroxycinnamates and flavonoids that includes edible fibre with numerous health benefits including weight loss, improve digestion, lower LDL cholesterol, and boost immune system. However, there is no large-scale production of dragon fruit because the seed storage viability is not reliable; the present study aims to employ tissue culture techniques supplied with different plant growth regulators (PGRs), the strength of growth media, and carbon sources. Seed germination was determined by growing the seeds in media enriched with benzyl aminopurine (BAP) 1 mg/L, 2 mg/L BAP, and 15 mg/L gibberellins (GA). Then, the seed growth was measured under different strengths of Murashige and Skoog (MS) basal media, which are full strength, 1/2, 1/4 and 1/8 strength, that promoted the seed germination the most. The percentage of seed germination was determined, and the effects of seed germination was measured by the period of seed to germinate, shoot length, and root length of the plants. In this study, all the dragon fruit seeds were successfully germinated. The seed shows the higher germination is MS + 2 mg/L BAP within 2 days, but the elongation of the shoot is not the fastest. The seed germination is effective in 1/8 media strength on day 2; the seeds are already germinated. However, the elongation for roots and shoots is the best in 1/2 media strength. The effect of carbon sources influences the fastest day to germinate, demonstrated in sucrose 30 g/L but not for root and shoot length. The 30 g/L glucose enhances the root length the highest, which is 2.48 cm. The average shoot length shows in TCS0 and TCS3 was similar, which was 1.38 cm. The effect of carbon sources that boost the shoot length the most is in TCS3 (2.04 cm), fructose 15 g/L. Those factors should be considered to enhance the best condition for dragon fruit planting and achieve the large-scale production,