STUDIES OF IN-VIVO AND IN-VITRO GERMINATION ABILITY OF DRAGON FRUIT (Hylocereus undatus)

Abstract

Dragon fruit (Hylocereus undatus) is a well-popularized fruit species incountries like Thailand, China and have a great potential for cultivation insemi-arid regions of Sri Lanka. Plant propagation studies have not beencarried out in Sri Lanka, and hence objective of this research was to study thein-vivo and in-vitro germination of Dragon fruit seeds and to select a suitablemedia for in-vitro establishment. Wet filter papers, wet sand, and wet coirdust were used to study the in-vivo germination and Hormone free, MSmedium, Anderson's Rhododendron medium, and McCown Woody Plantmedium incorporated with 1 g/l of activated charcoal was used to study invitrogermination. In-vitro germination percentage was higher (lOa % inAnderson, 98.5 % in MS, and 96 % in WP) when compared to seedsgerminated in in-vivo conditions (50 %in Filter paper method, 45 % in Sand,and 35 % in Coir dust). Seedlings germinated in in-vitro conditions showedhealthy vigorous growth and 15, 14, and 11 mm seedling heights wereobserved with fully opened cotyledons at the end of second week inAnderson, MS, and WP medium respectively. Though similar plant heights(l5±2 mm) were observed, appearance of the seedlings was very weak, andcotyledons had not fully opened under in-vivo conditions. In both in-vivo andin-vitro conditions root system development was similar and root formationwas observed within 6 days with 4±2 mm root length. Germination, plantheight, and appearance of plants were best in Anderson medium. Resultsrevealed that seeds could be successfully germinated in in-vitro conditionsusing Anderson medium supplemented with 1 mg/l activated charcoal as theestablishment medium.