Abstract Kemampuan Bakteri Kitinolitik Asal Rizosfer Tanaman Karet Dalam Akar Putih Pada Bibit Karet
KEMAPUAN BAKTERI KITINOLITIK ASAL RIZOSFER TANAMAN
KARET DALAM MENGENDALIKAN JAMUR AKAR PUTIH PADA
BIBIT KARET
ABSTRAK
Pembudidayaan tanaman karet dapat dihambat oleh adanya serangan penyakit.
Penyakit tanaman karet disebabkan oleh Rigidoporus lignosus yang menyerang
akar tanaman karet sedangkan Colletortrichum dan Corynespora menyerang daun
tanaman karet. Penelitian ini bertujuan untuk menguji kemampuan bakteri
kitinolitik dari peneltian sebelumnya yang diisolasi dari rizosfer tanaman karet
dalam menghambat pertumbuhan R. lignosus Corynespora dan Colletrotrichum
secara in vitro serta melihat kemampuannya dalam menurunkan serangan
R.lignosus pada bibit tanaman karet secara in vivo. Isolat bakteri kitinolitik
dengan kode isolat FS 4 dan FS 7 digunakan dalam penelitian ini. Hasil penelitian
menunjukkan bahwa kedua isolat mampu menghambat pertumbuhan jamur
patogen. Isolat FS 7 merupakan isolat dengan diameter zona hambat yang lebih
tinggi. Diameter zona hambat pada R. lignosus 21.35 mm, Corynespora 17 mm
dan Colletotrichum 21.5. Sedangakan isolat bakteri kitinolitik kode FS 4 terhadap
R. lignosus, Corynespora dan Colletotrichum diameter zona hambat masingmasing 14.5 mm, 14.5 mm dan 20.15. Pada uji in vivo dilakukan dengan dua
perlakuan. Perlakuan I adalah pemberian bakteri kitinolitik satu hari setelah
inokulasi jamur patogen pada akar tanaman karet sedangkan perlakuan II aplikasi
bakteri kitinolitik 30 hari setelah inokulasi jamur patogen. Kontrol positif
inokulasi jamur patogen tanpa pemberian bakteri kitinolitik sedangkan kontrol
negatif tidak diberikan bakteri kitinolitik ataupun jamur patogen. Hasil penelitian
menunjukkan bakteri kitinolitik mampu menurunkan serangan R. lignosus pada
bibit tanaman karet. Perlakuan I intensitas serangan dengan pemberian bakteri FS
4 sebesar 0% dan FS 7 sebesar 5 %. Pada perlakuan II dengan pemberian bakteri
FS 4 intensitas serangan awal 40% dan intensitas serangan akhir 30 sedangakan
FS 7 intensitas serangan awal 30% dan intensitas serangan akhir 30%. Kontrol
negatif tidak menunjukkan adanya serangan penyakit sedangkan kontrol positif
intensitas serangan sebsar 65 %. Penurunan intensitas serangan pada isolat
bakteri FS 4 sebesar 83.33 % dan FS 7 33.33 %.
Kata kunci: Bakteri kitinolitik rizosfer, R. lignosus, jamur patogen, bibit tanaman
karet.
v
THE ABILITY OF CHITINOLYTIC BACTERIA FROM RUBBER PLANT
RHIZOSPHERE TO CONTROL WHITE ROOT DISEASE IN RUBBER
SEEDLINGS
ABSTRACT
Cultivation of rubber plant is inhibited by diseases. The diseases attacks rubber
plants caused by Rigidiporus lignosus which damages rubber roots while
Colletotrichum and Corynespora cause leaf diseases. The purpose of this study
was to examine the ability of chitiniolytic bacteria which was isolated from
rhizosphere of rubber plants in previous study to inhibit R. lignosus, Corynespora
and Colletotrichum growth by in vitro study. In vivo study was to examine its
ability to control white root disease caused by R. lignosus in rubber seedlings.
Rhizospere chitinolytic bacterial isolates which had FS 4 and FS 7 code were
used in this study. The result showed that both of isolates had abilities in
inhibiting pathogenic fungal growth which FS 7 isolate showed higher inhibition
zone. Inhibition zone of R. lignosus, Colletotrichum, Corynespora were 21.35 mm
17 mm, and 21. 5 mm, while inhibition zone of rhizospehere chitinolytic bacteria
FS 4 code were 14.5 mm, 14.5 mm and 20.15 mm respectively. The study of in
vivo was conducted using two treatments. The first treatment was application of
chitinolytic bacteria one day after pathogenic fungi had been inoculated while
second treatment was applied by chitinolytic bacterial 30 days after pathogenic
fungi had been inoculated. Positive control was inoculation of pathogenic fungi
without application of chitinolytic bacterial, while negative control was not
applied by neither chitinolytic bacteria nor pathogenic fungi. The result showed a
decline of disease intensity in rubber seedlings. The first treatment exhibited that
the diseases intensity of R. lignosus was 0% for FS 4 and 5% for FS 7 while
second treatment reduced from 40% to 15% for FS 4 and 30% to 20% for FS 7.
Negative control did not show diseases while diseases intensity of positive control
was 65%. Decreasing of disease intensity was 83.33% for FS 4 and 33.33% for
FS 7 isolate.
Keyword: Rhizosphere chitinolytic bacteria, R. lignosus, Pathogenic fungi,
Rubber seedling.
vi
KARET DALAM MENGENDALIKAN JAMUR AKAR PUTIH PADA
BIBIT KARET
ABSTRAK
Pembudidayaan tanaman karet dapat dihambat oleh adanya serangan penyakit.
Penyakit tanaman karet disebabkan oleh Rigidoporus lignosus yang menyerang
akar tanaman karet sedangkan Colletortrichum dan Corynespora menyerang daun
tanaman karet. Penelitian ini bertujuan untuk menguji kemampuan bakteri
kitinolitik dari peneltian sebelumnya yang diisolasi dari rizosfer tanaman karet
dalam menghambat pertumbuhan R. lignosus Corynespora dan Colletrotrichum
secara in vitro serta melihat kemampuannya dalam menurunkan serangan
R.lignosus pada bibit tanaman karet secara in vivo. Isolat bakteri kitinolitik
dengan kode isolat FS 4 dan FS 7 digunakan dalam penelitian ini. Hasil penelitian
menunjukkan bahwa kedua isolat mampu menghambat pertumbuhan jamur
patogen. Isolat FS 7 merupakan isolat dengan diameter zona hambat yang lebih
tinggi. Diameter zona hambat pada R. lignosus 21.35 mm, Corynespora 17 mm
dan Colletotrichum 21.5. Sedangakan isolat bakteri kitinolitik kode FS 4 terhadap
R. lignosus, Corynespora dan Colletotrichum diameter zona hambat masingmasing 14.5 mm, 14.5 mm dan 20.15. Pada uji in vivo dilakukan dengan dua
perlakuan. Perlakuan I adalah pemberian bakteri kitinolitik satu hari setelah
inokulasi jamur patogen pada akar tanaman karet sedangkan perlakuan II aplikasi
bakteri kitinolitik 30 hari setelah inokulasi jamur patogen. Kontrol positif
inokulasi jamur patogen tanpa pemberian bakteri kitinolitik sedangkan kontrol
negatif tidak diberikan bakteri kitinolitik ataupun jamur patogen. Hasil penelitian
menunjukkan bakteri kitinolitik mampu menurunkan serangan R. lignosus pada
bibit tanaman karet. Perlakuan I intensitas serangan dengan pemberian bakteri FS
4 sebesar 0% dan FS 7 sebesar 5 %. Pada perlakuan II dengan pemberian bakteri
FS 4 intensitas serangan awal 40% dan intensitas serangan akhir 30 sedangakan
FS 7 intensitas serangan awal 30% dan intensitas serangan akhir 30%. Kontrol
negatif tidak menunjukkan adanya serangan penyakit sedangkan kontrol positif
intensitas serangan sebsar 65 %. Penurunan intensitas serangan pada isolat
bakteri FS 4 sebesar 83.33 % dan FS 7 33.33 %.
Kata kunci: Bakteri kitinolitik rizosfer, R. lignosus, jamur patogen, bibit tanaman
karet.
v
THE ABILITY OF CHITINOLYTIC BACTERIA FROM RUBBER PLANT
RHIZOSPHERE TO CONTROL WHITE ROOT DISEASE IN RUBBER
SEEDLINGS
ABSTRACT
Cultivation of rubber plant is inhibited by diseases. The diseases attacks rubber
plants caused by Rigidiporus lignosus which damages rubber roots while
Colletotrichum and Corynespora cause leaf diseases. The purpose of this study
was to examine the ability of chitiniolytic bacteria which was isolated from
rhizosphere of rubber plants in previous study to inhibit R. lignosus, Corynespora
and Colletotrichum growth by in vitro study. In vivo study was to examine its
ability to control white root disease caused by R. lignosus in rubber seedlings.
Rhizospere chitinolytic bacterial isolates which had FS 4 and FS 7 code were
used in this study. The result showed that both of isolates had abilities in
inhibiting pathogenic fungal growth which FS 7 isolate showed higher inhibition
zone. Inhibition zone of R. lignosus, Colletotrichum, Corynespora were 21.35 mm
17 mm, and 21. 5 mm, while inhibition zone of rhizospehere chitinolytic bacteria
FS 4 code were 14.5 mm, 14.5 mm and 20.15 mm respectively. The study of in
vivo was conducted using two treatments. The first treatment was application of
chitinolytic bacteria one day after pathogenic fungi had been inoculated while
second treatment was applied by chitinolytic bacterial 30 days after pathogenic
fungi had been inoculated. Positive control was inoculation of pathogenic fungi
without application of chitinolytic bacterial, while negative control was not
applied by neither chitinolytic bacteria nor pathogenic fungi. The result showed a
decline of disease intensity in rubber seedlings. The first treatment exhibited that
the diseases intensity of R. lignosus was 0% for FS 4 and 5% for FS 7 while
second treatment reduced from 40% to 15% for FS 4 and 30% to 20% for FS 7.
Negative control did not show diseases while diseases intensity of positive control
was 65%. Decreasing of disease intensity was 83.33% for FS 4 and 33.33% for
FS 7 isolate.
Keyword: Rhizosphere chitinolytic bacteria, R. lignosus, Pathogenic fungi,
Rubber seedling.
vi