Aktivitas Nitrat Reduktase dan Kandungan N-Total Daun Lidah Buaya (Aloe vera L.) Pada Lahan Berpasir di Pesisir Pantai Pandan Sari, Daerah Istimewa Yogyakarta

Partiningsih, Dr. Rarastoeti Pratiwi, M.Sc.

2003 | Skripsi | S1 BIOLOGI

INTISARI Penelitian ini bertujuan untuk mengetahui aktivitas nitrat reduktase dan kandungan N-total daun lidah buaya (Aloe vera L.) pada lahan berpasir di pesisir pantai Pandan Sari, Daerah Istimewa Yogyakarta. Bibit lidah buaya berumur satu setengah bulan digunakan dalam penelitian ini. Lidah buaya ditanam pada lahan berpasir I (kandungan pasir 90%), lahan berpasir II (kandungan pasir 85%), lahan berpasir III (kandungan pasir 80%), dan kontrol (kandungan pasir 70%). Rancangan percobaan yang digunakan ialah rancangan acak lengkap dengan lima kali ulangan untuk masing-masing lahan. Aktivitas nitrat reduktase daun diukur pada saat tanaman berumur 6 minggu dan 12 minggu dengan metode spektrofotometri. Kandungan N-total daun diukur pada saat tanaman berumur 12 minggu dengan metode mikrokjeldahl. Parameter lingkungan yang diukur meliputi intensitas cahaya, temperatur udara, kelembaban udara, pH tanah, salinitas tanah, kandungan air tanah, tekstur tanah, dan kecepatan angin. Data yang diperoleh dianalisis dengan ANOVA dilanjutkan dengan uji Least Significant Difference (LSD) dan analisis korelasi (p ? 0,05). Hasil penelitian menunjukkan bahwa pada saat tanaman berumur 6 minggu, aktivitas nitrat reduktase tertinggi terdapat pada daun lidah buaya yang ditanam pada lahan berpasir II, yaitu sebesar 1,56 µmol/gram/jam dan terendah pada kontrol, yaitu 0,21 µmol/gram/jam. Aktivitas nitrat reduktase tertinggi pada saat tanaman berumur 12 minggu terdapat pada lahan berpasir I, yaitu 0,35 µmol/gram/jam dan terendah pada kontrol, yaitu 0,15 µmol/gram/jam. Kandungan N-total tertinggi terdapat pada daun lidah buaya yang ditanam pada kontrol, yaitu 1,79% dan terendah pada lahan berpasir I, yaitu 0,92%. Kandungan N-total daun lidah buaya pada lahan berpasir II lebih tinggi daripada lahan berpasir I dan III. Dengan demikian dapat dikatakan bahwa aktivitas nitrat reduktase dan kandungan N-total daun lidah buaya pada lahan berpasir II lebih tinggi daripada lahan berpasir I dan III di pesisir Pantai Pandan Sari, Daerah Istimewa Yogyakarta.

ABSTRACT The aims of this study were to know nitrat reductase activities and total nitrogen content in lidah buaya (Aloe vera L.) leaf that grown in coastal sands at Pandan Sari coast, Daerah Istimewa Yogyakarta. One and half month lidah buaya plant were used in this study. Lidah buaya plant were grown in coastal sand I (sand content 90%), coastal sand II (sand content 85%), coastal sand III (sand content 80%), and control (sand content 70%). Completely randomized design with five replicates was used in this experiment for each coastal sand I, II, III, and control. Nitrat reductase activities and total nitrogen in leaf were used as parameters. Nitrat reductase activities were measured after 6 weeks and 12 weeks experiment by spectrophotometry method. Total nitrogen was measured after 12 weeks experiment by mikrokjeldahl method. Environmental parameters measured included light intensity, air temperature, air humidity, soil pH, soil salinity, soil water content, soil texture, and wind velocity. The collected data were analyzed by ANOVA, followed by Least Significant Difference (LSD) and correlation analysis (p ? 0.05). The results showed that the highest nitrat reductase activities were obtained in lidah buaya grown in coastal sand II, that were 1.56 µmol/gram/hour, while the lowest was in control, that were 0.21 µmol/gram/hour after 6 weeks experiment. The highest nitrat reductase activities were obtained in coastal sand I, that were 0.35 µmol/gram/hour, while the lowest was in control, that were 0.15 µmol/gram/hour measured after 12 weeks experiment. The highest total nitrogen in lidah buaya leaf was obtained in control, that were 1.79%, and the lowest was in coastal sand I, that were 0.92%. Total nitrogen in lidah buaya grown in coastal sand II was higher than coastal sand I and III. It can be said that nitrat reductase activities and total nitrogen in lidah buaya leaf grown in coastal sand II were higher than coastal sand I and III at Pandan Sari coast, Daerah Istimewa Yogyakarta.

Kata Kunci : Aloe vera (lidah buaya), Nitrat reduktase, Lahan berpasir, pesisir , Spektrofotometri