Judul: Morphophysiological and Anatomical  Responses of Sun and Shade Plants to Sunlight Intensity Stress
Abstrak: Setiap tumbuhan mempunyai kebutuhan intensitas cahaya tertentu. Apabila tumbuhan menerima intensitas cahaya yang tidak sesuai dengan kebutuhannya, akan menyebabkan pertumbuhan dan perkembangan yang berbeda. Tujuan penelitian ini adalah untuk mengetahui perbedaan ciri morfologi, fisiologi, dan anatomi tanaman suka sinar matahari (Catharanthus roseus) dan suka teduhan (Spathiphyllum sp.) yang ditanam pada berbagai tingkat intensitas cahaya, yakni naungan 0% (sinar matahari penuh), 50% dan 95%. Tanaman dinaungi menggunakan paranet berkerapatan berbeda di Kebun Percobaan Leuwikopo, Kampus Dramaga, IPB University. Analisis fotosintesis dilakukan menggunakan Li-6400 portable photosynthesis system dengan Photosynthetic Photon Flux Density (PPFD) 2000, 800 dan 50 µmol/m/s. Biomassa terbesar terjadi pada naungan 50% untuk kedua jenis tanaman, dan menurun pada naungan yang lebih tinggi pada tapak dara, dan kondisi sinar matahari penuh pada peace lily. Kandungan klorofil, luas, dan sudut daun meningkat seiring dengan penambahan naungan. Perlakuan naungan tidak berpengaruh nyata terhadap kadar air total kedua jenis tanaman. Asimilasi CO2 (Pn) terbaik terukur dengan PPFD 800 dan 2000 µmol/m/s, pada tanaman naungan 50%, meskipun tidak berbeda nyata dengan tanaman naungan 0% dan 95%. Hal ini menunjukkan perlakuan naungan tidak menyebabkan kerusakan perangkat fotosintesis. Struktur jaringan daun terbaik (rapat) dimiliki tapak dara naungan 0% dan peace lily naungan 95%., Plant species have certain requirement for light intensity, therefore if plants receive inappropriate light intensity, it will cause adverse growth and development. The aim of this research was to observe differences in the morphological, physiological, and anatomical characteristics of sun plant periwinkle (Catharanthus roseus) and shade plant Spathiphyllum sp. grown at different levels of light intensity, i.e., 0% shade (full sunlight), 50% shade, and 95% shade. Light intensity treatment was provided by placing the plants under para-net with different density in Leuwikopo Experimental Garden, Dramaga Campus, IPB University. Photosynthesis analysis was carried out using the Li-6400 portable photosynthesis system, with Photosynthetic Photon Flux Density (PPFD) adjusted at 2000, 800 and 50 µmol/m/s. The largest biomass resulted in 50% shade for both types of plants, which decreased significantly by higher shading for periwinkle, while for peace lily it decreased under full sunlight. Chlorophyll content, leaf area and leaf angle increased with the intensed shade density. Shading treatment had no significant effect on total water content of both plant species. The best photosynthetic CO2 assimilation (Pn) measured with PPFD 800 and 2000 µmol/m/s occurred in the plants treated with 50% shading, even though not significantly different with the plants without shading and with 95% shading, suggesting that shading treatments did not cause the damage of photosynthetic apparatus. The most compact anatomical structure was shown by the periwinkle with 0% shading and the peace lily with 95% shading.
Keyword: Catharanthus roseus, chlorophyll, photosynthesis, shade, Spathiphyllum sp