GROWTH INHIBITORY EFFECT OF MAHOGANY (Swietenia macrophylla King) LEAF LITTER ON LETTUCE (Lactuca sativa L. var. Legacy) SEEDLINGS

ARNIA SARI MUKAROMAH, Dr. Yekti Asih Purwestri, M.Si.

2017 | Tesis | S2 Biologi

Skrining potensi alelopati serasah daun Mahoni (Swietenia macrophylla King) dalam interaksi antar tumbuhan menggunakan sandwich bioassay method dan growth-inhibitory bioassay belum pernah dilaporkan. Tujuan penelitian ini adalah menentukan dan mengelompokkan potensi serasah daun Mahoni (Swietenia macrophylla King) yang dievaluasi menggunakan sandwich bioassay method serta menentukan aktivitas penghambatan pertumbuhan dan aktivitas spesifik (EC50) dari serasah Mahoni (Swietenia macrophylla King) terhadap radikula bibit selada (Lactuca sativa L. var. Legacy). Sandwich method dan growth-inhibitory bioassay digunakan untuk mengevaluasi potensi alelopati pada searasah daun S. Macrophylla. Hasil menunjukkan bahwa serasah daun S. macrophylla menunjukkan aktivitas alelopati kuat ketika dibandingkan dengan serasah daun dari 46 spesies dan termasuk sepuluh teratas spesies serasah daun yang memiliki alelopati. Peningkatan konsentrasi serasah daun S. macrophylla seiring dengan penghambatan pemanjangan radikula bibit selada dibandingkan dengan kontrol. Berdasarkan analisis regresi linier, konsentrasi efektif (EC50) S. macrophylla diperkirakan 3.25 mg D.W. eq. mL-1 dan dipertimbangkan memiliki aktivitas penghambatan pertumbuhan yang kuat terhadap pemanjangan radikula selada. Hasil menyarankan adanya kemungkinan potensi alelopati serasah daun dalam interaksi antar tumbuhan dibawah pohon S. macrophylla.

Screening the allelopathic potential of Mahogany (Swietenia macrophylla King) leaf litter in plant-plant interaction using the sandwich bioassay method and growth-inhibitory bioassay have not been reported. The research objectives were to determine and categorize the allelopathic potential of Mahogany (Swietenia macrophylla King) leaf litter evaluated by the sandwich bioassay method and to determine the growth inhibitory activity and the specific activity (EC50) of Mahogany (Swietenia macrophylla King) leaf litter on radicle lettuce (Lactuca sativa L. var. Legacy) seedlings. The sandwich method and growth-inhibitory bioassay were used to evaluate allelopathic potential of S. macrophylla leaf litter. The results showed that S. macrophylla leaf litter indicated strong allelopathic activity when compared with 46 leaf litter species and was included in the top ten of allelopathic leaf litter species. Enhancing S. macrophylla leaf litter concentration was concomitant with inhibition of radicle lettuce seedlings elongation compared with the control. According to the linier regression analysis, the effective concentration (EC50) of S. macrophylla was estimated to be 3.25 mg D.W. eq. mL-1 and was considered to have strong growth-inhibitory activity on lettuce radicle elongation. The results suggest the possibility of allelopathic potential of leaf litter in plant-plant interaction under S. macrophylla trees.

Kata Kunci : Allelopathy; EC50; Leaf litter; Mahogany; Sandwich Method