SKRINING Streptomyces sp. ISOLAT LOMBOK SEBAGAI PENGENDALI HAYATI BEBERAPA JAMUR PATOGEN TANAMAN Screening of Lombok Isolates of Streptomyces Sp. as a Biological Control Agent of Some Fungal Plant Pathogens

Abstract

Penelitian bertujuan untuk mendapatkan Streptomyces sp. isolat Lombok yang memiliki kemampauan antagonis yang dapat digunakan sebagai pengendali hayati beberapa jamur patogen tanaman di pulau Lombok. Penelitian dilaksanakan di lapang dan di Laboratorium Mikrobiologi Fakultas Pertanian Universitas Mataram mulai dari bulan April sampai dengan bulan Nopember 2007. Dari hasil penelitian diperoleh 45 isolat Streptomyces sp. Isolat tersebut 9 terdiri dari isolat dari rizosfer cabe Steling, 10 dari rizosfer tomat Bayan, 13 dari rizosfer bawang Sembalun, dan 13 dari rizosfer cabe Aikmal.  Data dianalisis dengan analisis varian, dan uji lanjut menggunakan uji beda nyata jujur pada taraf 5%. Warna koloni isolat yang berhasil di isolasi dikelompokan dalam warna putih, coklat, abu-abu, kuning, hijau, hitam dan ungu. Semua isolat bereaksi gram positif pada pengecatan gram. Hasil penelitian menunjukkan bahwa sebanyak 20 isolat (44,4%) dari isolat Streptomyces sp. yang berhasil diisolasi mampu menghambat pertumbuhan jamur patogen tanaman pada uji antagonis secara berpasangan. Satu isolat (BSi) mampu menghambat tiga jamur patogen tanaman (Fusarium oxysporum, Rhizoctonia solani, Sclerotium rolfsii). Dua isolat (CSb dan CSk) menghambat pertumbuhan dua jamur patogen tanaman (F.  oxysporum, R. solani). Tiga isolat (CSa, CSe, CSg) hanya mampu menghambat  F. oxysporum, satu isolat (CAl) hanya mampu menghambat S. rolfsii, dan 13 isolat lainnya hanya menghambat R. solani.  Persentase hambatan oleh Streptomyces sp. terhadap jamur patogen tanaman bervariasi dari yang paling kecil 20% (Streptomyces sp. isolat CAj terhadap R. solani), sampai yang paling besar 70% (Streptomyces sp. isolat BSi terhadap S. rolfsii).

ABSTRACT

The objective of the research was to obtain Lombok isolate of Streptomyces sp. those has the antagonist ability can be used as biological control agent of several fungal plan pathogens in Lombok Island. The experiments were undertaken in the field and Laboratorium of Microbiology the Faculty of Agriculture Mataram University started from April up to November 2007.The result of the research showed that 45 isolates of Streptomyces sp. have been obtained.  Those isolates includes 9 isolates obtained from the rhizosphere of chili in Steling, 10 from the rhizosphere of tomato in Bayan, 13 from the rhizosphere of chili in Aikmal.  The colour of the colony of the isolate that has been successfully isolated were grouped in the colour of white, brown, grey, yellow, green, black, and purple.  All isolates are gram-positive bacteria according to gram staining test. As much as 20 isolates (44,4%) of isolates of Streptomyces sp. being isolated were capable of inhibiting the growth of fungal plant pathogens according to antagonism test.  One isolate (BSi) was capable of inhibiting three fungal plant pathogens (Fusarium oxysporum, Rhizoctonia solani, and Sclerotium rolfsii).  Two islates (CSb and CSk) were capable in inhibiting two fungal plant pathogens (F. oxysporum and R. solani).  Three isolates (CSa, CSe, CSg) were only able to inhibit F.  oxysporum, one isolate (CAl) was only capable in inhibiting S. rolfsii, and the other 13 isolates were only able to inhibit R. solani.  The percentage of inhibition of the fungal plan pathogens by Streptomyces sp. is varied from the smallest inhibition of 20% (Sterptomyces sp. isolate of CAj against R. solani) to the biggest inhibition of  70% (Streptomyces sp. isolate of BSi against S. rolfsii).