POTENSI BAKTERI ENDOFIT MENGINDUKSI KETAHANAN TANAMAN LADA TERHADAP INFEKSI Meloidogyne incognita

ABSTRAK Meloidogyne incognita, merupakan salah satu organisme peng-ganggu (OPT) penyebab penyakit kuning pada tanaman lada dan dapatmengakibatkan penurunan hasil sampai 32%. Beberapa teknik untukmengendalikan patogen ini telah dilakukan tetapi belum memberikan hasilyang memuaskan. Pengendalian biologi dengan menggunakan bakteriendofit merupakan salah satu alternatif pengendalian yang cukup men-janjikan untuk dapat mengatasi permasalahan nematoda penyakit tanaman.Penelitian ini telah dilakukan di Laboratorium Bakteriologi danNematologi Departemen Proteksi Tanaman Institut Pertanian Bogor, danRumah Kaca Balai Penelitian Tanaman Rempah dan Aneka TanamanIndustri Pakuwon Sukabumi dari bulan Mei sampai November 2009.Kegiatan yang dilakukan adalah: 1) Seleksi beberapa isolat bakteri endofituntuk mengendalikan nematoda M. incognita pada tanaman lada dan 2)Potensi induced systemic resistance (ISR) dan analisis asam salisilat sertaperoksidase. Isolat bakteri endofit yang digunakan adalah isolat bakteriendofit potensial yang diisolasi dari akar nilam. Akar tanaman ladadirendam dalam suspensi bakteri endofit, selanjutnya diinokulasi dengan500 ekor larva 2 M. incognita. Sebulan setelah inokulasi tanamandibongkar diamati populasi nematoda dan pertumbuhan tanaman. AnalisisISR dilakukan dengan metode split root system dilanjutkan dengananalisis kadar asam salisilat dan peroksidase. Penelitian mengunakanRancangan Acak Lengkap. Hasil penelitian menunjukkan bahwa bakteriendofit dapat menekan jumlah puru dan populasi nematoda di dalam akar.Penekanan tertinggi pada isolat MSK (97,93%) tidak berbeda nyatadengan isolat BAS, TT2, dan NJ46 yaitu 97,35; 95,22; dan 92,14%.Berdasarkan analisis split root system, ke 4 isolat tersebut dapat meng-induksi ketahanan tanaman lada secara sistemik dengan mekanismepeningkatan kandungan asam salisilat dan peroksidase di dalam akar. Kata kunci : Bakteri endofit, penyakit kuning, Piper nigrum L.,Meloidogyne incognita, induksi ketahanan ABSTRACT The use of endophytic bacteria to induce plant resistanceagainst infection of root-knot nematode (Meloidogyneincognita) on black pepper Root-knot nematode (Meloidogyne incognita) is one of important patho-gens causing yellow disease on black pepper. As a result of this pathogenattack can lower the results up to 32%. Several control methods have beendone successful to control pathogen. Biological control using endophyticbacteria is one of prospective alternative control methods to overcomenematode problem. The research had been conducted in the Laboratory ofBacteriology and Nematology Department of Plant Protection, BogorAgricultural University (IPB) and in greenhouse of Indonesian Spices andIndustrial Crops Research Institute (ISICRI) Sukabumi. The objectives ofthis study were : 1) Selection of endophytic bacteria to control M.incognita nematodes on black pepper and 2) Potential of induced systemicresistance (ISR) and analysis of salicylic acid and peroxidase. Endophyticbacterial isolates used were endophytic potential bacterial isolates isolatedfrom the roots of patchouli. Pepper plant roots were soaked in anendophytic bacterial suspension, then inoculated with 500 larvae of 2 M.incognita. A month after inoculation, the plants were dismantled andobserved population of nematodes and plant growth. ISR analysis wasperformed by the method of split root system followed by analysis ofsalicylic acid and peroxidase contents. The research was arranged usingCompletely Randomized Design. The results showed that endophyticbacteria were able to suppress the amount of gall and nematode populationin roots. The highest suppression was on MSK isolate (97.93%) which wasnot significantly different from BAS, TT2, and NJ46 isolates, namely97.35, 95.22, and 92.14%, respectively. The analysis of split root systemshowed that the 4 isolates were able to induce systemic resistance of blackpepper with a mechanism of increase in salicylic acid and peroxidasecontents in roots. Key words : Endophytic bacteria, yellow disease, Piper nigrum L.,Meloidogyne incognita, induce systemic resistance