Karakter Jamur Ceratocystis sp. Penyebab Penyakit Busuk Batang pada Acacia decurrens dan Status Penyakitnya di Taman Nasional Gunung Merapi, Yogyakarta

Abstract

Acacia decurrens merupakan salah satu jenis tanaman yang tumbuh mendominasi kawasan Taman Nasional Gunung Merapi (TNGM), pasca erupsi Gunung Merapi tahun 2010. Sekitar 80% tegakan A. decurrens di kawasan tersebut menunjukkan gejala busuk batang akibat infeksi jamur Ceratocystis sp. yang umumnya dipicu oleh luka gerekan kumbang dari kelompok ambrosia. Penelitian bertujuan untuk : (1) mendeskripsikan karakter morfologi jamur Ceratocystis sp., serta kemampuannya beradaptasi pada beberapa jenis tanaman hutan, (2) mengevaluasi status penyakit busuk batang oleh jamur Ceratocystis sp. Karakter morfologi dan kemampuan adaptasinya pada inang akasia, melina, jabon, sengon, dan jati dilakukan di Laboratorium Perlindungan dan Kesehatan Hutan, Fakultas Kehutanan UGM. Survei untuk evaluasi status penyakit busuk batang dilakukan pada bulan Februari sampai Agustus 2014 di demplot restorasi pasca erupsi Merapi (luas 8,4 ha), dengan intensitas sampling 8%. Berdasarkan karakter morfologi, terdapat 2 isolat jamur Ceratocystis sp. yaitu asal lembah (L) dan dari bukit (B) dengan warna koloni krem, luas koloni 20-22 cm2 pada umur 14 hari, membentuk konidia menyerupai tong, dan silindris. Sifat lainnya yaitu memiliki kemampuan yang sama untuk tumbuh, mengkolonisasi, dan menginfeksi inang akasia, sengon, jabon, dan melina, tetapi tidak mampu tumbuh pada inang jati. Berdasarkan luas serangan, status penyakit busuk batang berkisar antara sangat umum sampai menyebar luas (luas serangan = 54-100%), dengan tingkat keparahan bekisar antara ringan sampai parah (intensitas penyakit = 15-67%).

Kata kunci: Ceratocystis sp., Acacia decurrens, luas serangan, intensitas penyakit, Taman Nasional Gunung Merapi.

Characteristic of stem rot diseases caused by Ceratocystis sp. on Acacia decurrens and its status in Gunung Merapi National Park, Yogyakarta

Abstract

Mount Merapi National Park (TNGM) has been dominated by Acacia decurrens after the eruption in 2010. Almost 80% of A. decurrens trees showed stem rot diseases caused by Ceratocystis sp. which may associate with stem wound induced by ambrosia beetle and other physical injuries. The research objective were (1) to characterize the morphological feature, in vitro growth, and ability to adapt, colonize as well as to infect akasia, jabon, sengon, melina and jati sedlings, (2) to evaluate the status of stem rot disease in TNGM demonstration plot. Laboratory work was conducted in order to study the morphological feature of the fungus, in vitro growth on PDA media, and to evaluate its compatibility to growth, colonize, and infect on 5th month seedling of akasia, sengon, jati, jabon and melina. Field monitorings were conducted from February to August 2014 at the restoration plot (8.4 ha) at 8% sampling intensity. Disease status was evaluated in order to ascertain the disease incidence and severity of stem rot disease at the demonstration plot area. Two Ceratocistys isolates found from the hill (B) and valley (L) had similar characteristics on morphologic features i.e. cream color, 20 to 22 cm2 colony size at 14 days growth in PDA media, having both cylindrical and barrel shaped conidia. The other characteristics of the Ceratocistys were an ability to growth, to colonize, and to infect akasia, sengon, melina and jabon, except on jati. The status of stem rot disease was ranged from highly common to widespread (disease incidence = 54%-100%) as the disease severity status was ranged from low to severe (disease severity = 15%-67%).