팔레높시스 기내 배양 시 광도(PPF)가 묘의 생장, 광합성 및 순화에 미치는 영향

Phalaenopsis ‘Amaglade’ plantlets were cultured in vitro under different photosynthetic photon flux (15, 30, 60, 90 μ㏖ㆍm?²ㆍs?¹) to investigate characteristics of growth, photosynthesis, and acclimatization. CO₂ concentration inside the culture vessel was maintained the highest at 15 μ㏖ㆍm?²ㆍs?¹ both day and night, while maintained the lowest at 60 μ㏖ㆍm?²ㆍs?¹. Photosynthetic rate started to increase just before the beginning darkness and maintained high level until the end of darkness, showing a typical CAM photosynthesis. Plantlet growth was greater at high PPFs (60, 90 μ㏖ㆍm?²ㆍs?¹) compared with low PPFs (15, 30 μ㏖ㆍm?²ㆍs?¹). Low PPFs decreased fresh weight, dry weight, and leaf and root development. After acclimatization, photosynthetic rate was measured at days 2, 15, and 40, respectively. Photosynthetic rates dropped right after acclimatization in all plantlets, increased thereafter and reached normal level after 40 days of acclimatization. Plantlets cultured at a high PPF of 60 μ㏖ㆍm?²ㆍs?¹ showed the highest photosynthetic rate, shoot and root growth, and 100% of plantlet survival at the end of acclimatization, while those cultured at a 15 μ㏖ㆍm?²ㆍs?¹ PPF exhibited the lowest plantlet growth and survival (66.7%). The results indicate that the increase of PPF level was crucial for both growth and acclimatization of Phalaenopsis ‘Amaglade’ plantlets.