Lekawatana, Setapong2018-06-202018-06-201986http://hdl.handle.net/10125/56158Plants of Heliconia stricta Huber 'Dwarf Jamaican' at different growth stages (1, 2, and 3 leaves per pseudostem) were treated with three different night temperature (15°, 20° and 25°C) under 8 hr daylength for U weeks. Pseudostems with 3 initial leaves and grown at 15°C night temperature had higher inflorescence production than plants with 1 or 2 initial leaves and grown at higher night temperature. The inflorescence production peaked at 19 weeks after the start of short daylength. Heliconia stricta 'Dwarf Jamaican' Huber, sympodial units in short (9 hr photoperiod) and long (approximately 16 hr photoperiod) daylengths were examined 1 year after planting from a single rhizome piece. An average of 4 generations were produced. The success and failure of sympodial units, their length and their relative angles were studied. The rhizome branching pattern might be hexagonal system. In the first generation, 4-2.5% of pseudostems grown under shortdaylength flowered while none of pseudostems grown under long daylength flowered. Pseudostem and inflorescence length were significantly longer in LD than in SD and increased with successive generations. Plants of Heliconia angusta Vell. at different growth stages (1-6 expanded leaves per pseudostem) were grown under 9, 10, 11, 12, and 14. hr photoperiods. The differences in daylength had no significant effect on the flowering status of pseudostems or average time to flower which was 17 weeks after the start of the daylength treatments. Apical meristems from plants of Heliconia stricta Huber 'Dwarf Jamaican' growing in short (9 hr photoperiod) or long (approximately 16 hr photoperiod) daylengths at different growth stages (1-6 expanded leaves) were observed. The inflorescence structure was distinguishable in plants under short daylength when pseudostems reached 3 or more expanded leaves while inflorescence structures could not be identified in pseudostems growing in long daylength.Thesis