Perangkat serologi untuk deteksi dini infeksi Ganoderma sp. pada kelapa sawit Serological device kit for early detection of Ganoderma sp. infection in oil palm

Abstract

Abstract

Basal stem rot caused by Ganoderma sp. is the most destructive disease in oil palm that difficult to control because its early symptom could not be detected easily. Serological technique that could detect early Ganoderma sp. infection in quick, simple, and cheap manner should be developed as one component for integrated disease management. A diagnostic device based on dot immunobinding assay (DIBA) for early detection of Ganoderma sp. infection in oil palm had been observed at laboratory, greenhouse and field experiment. Study result revealed that serological technique could detect antigen protein extract of Ganoderma mycelium as much as 138 µg/mL. Basal stem of young seedling that artificially be inoculated by the pathogen could also be clearly detected. At field experiment, Ganoderma sp. infection in oil palm plantation was marked with colour marking based on its infection stadium level to the palm oil. The colours are green, yellow, red, black, and white stating that the plant are healthy, mild infection, heavy infection, very heavy infection, and dead, respectively. Field experiment result showed that serological device kit gave strong reaction to antigen extracted from root and stem at red marking plant. The antigen extracted from healthy plant (green marking plant) was the weak one indicating that the plant is starting to be infected although the symptoms are not yet visually observed.

Abstrak

Busuk pangkal batang (BPB) yang disebabkan oleh Ganoderma sp. merupakan penyakit paling penting yang sulit ditanggulangi pada tanaman kelapa sawit karena gejala dini serangan sulit diketahui. Teknik serologi yang mampu mendeteksi dini infeksi Ganoderma sp. secara cepat, sederhana dan murah perlu dikembangkan sebagai salah satu komponen dalam pengelolaan penyakit secara terpadu. Teknik serologi dalam bentuk perangkat diagnostik berbasis dot immunobinding assay (DIBA) telah dirakit untuk mendeteksi infeksi Ganoderma sp. pada skala laboratorium, rumah kaca, dan lapang. Hasil pengujian menunjukkan bahwa perangkat diagnostik tersebut dapat mendeteksi ekstrak protein dari miselium Ganoderma sp sebesar 138 µg/mL. Keberadaan patogen pada bibit kelapa sawit yang diinfeksi buatan dapat dideteksi secara jelas dengan perangkat serologi tersebut. Deteksi tingkat infeksi Ganoderma sp. pada kebun kelapa sawit TM (skala lapang) dilakukan dengan mengambil sampel berdasarkan stadium infeksi (sehat, ringan, berat, sangat berat, mati) yang diberi kriteria warna hijau, kuning, merah, hitam, dan putih. Hasil uji di kebun kelapa sawit menunjukkan bahwa teknik serologi ini memberikan reaksi paling kuat terhadap antigen yang diekstraksi dari akar dan batang tanaman kriteria merah. Sedangkan reaksi paling lemah ditunjukkan oleh antigen yang diekstraksi dari tanaman kelapa sawit kode hijau yang mengindikasikan bahwa tanaman tanaman kelapa sawit di lapangan tersebut mulai terserang walaupun gejala penyakit belum terlihat secara visual.