溫度和光線對百香果生長及花芽形成之影響

Effects of Temperature and Light on Growth and Flower Formation of Passionfruit

溫度和光線對「台農一號」百香果扦插苗植株之生長和花芽形成具有交互作用。台北8、9月光線下（平均日射量397.5cal/cm²/day，日長12.86 hr），於人工氣候室三種溫度處理（日夜溫30/25、25/20、20/15 °C）。隨著溫度提高，營養生長顯著受到促進。花芽形成方面，則以25/20°C植株表現最佳，在較低節位即可形成花芽，且花芽不易夭折，但因其生長較快、葉間期短，故從處理至花芽形成之天數和花芽數與25/20 °C植株相近。而20/15°C之植株則無法形成花芽。至於10、11月之光線下（293.7cal/cm²/day，11.98hr），則處理的三種溫度均不能形成花芽。同一溫度下植株之營養生長量不如8、9月生長之植株，但高溫仍顯著較低溫促進營養生長。因此百香果之花芽形成，可能有一臨界溫度範圍，在極端溫度時無法形成花芽及開花；而在適合花芽形成之溫度，則光線之影響大於溫度。

The cutting plants of passionfruit cv. Tai-nung No.l were grown in phytotron with three temperature treatments (day/night temperature were 30/25、25/20、20/15°C). Under Aug.-Sep. light temperature were 30/25、25/20、20/15°C ). Under Aug.-Sep. light condition in Taipei (ave. solar radiation 397.5 cal/cm²/day, daylength 12.86 hr), The vegetative growth of the plants increased with the temperature. The plants at 25/20°C had lower node number to first flower bud and lower abortion rate of flower buds than those at 30/25°C. However, the plants at 30/25 °C which were due to higher growth rate had the similar days to first flower formation to those at 25/20°C. The plants at 20/15 °C rown in phytotron with three temperature treatments (day/night had no flower formation. Under Oct.-Nov. light condition (293.7 cal/cm²/day, 11.98 hr), the effect of temperature on vegetative growth was similar to that of Aug,-Sep. light condition in Taipei (ave. solar radia condition, while the plants at all three temperature treatments had no flower formation. Therefore, it is assumed that there is a critical level of temperature for flower formation in passionfruit. While in the suitable range of temperature for flower formation, the role of light on flower formation is more important than that of temperature.