Abstrak - (SPs) ITB

ABSTRAK
INDUKSI BAKTERI RIZOSFIR PADA TANAMAN TOMAT
UNTUK MENGENDALIKAN NEMATODA BENGKAK AKAR
(Meloidogyne spp.)
Oleh
Rika Alfianny
NIM 30611023
(Program Studi Doktor Biologi)
Penyakit Nematoda Bengkak Akar (NBA) yang disebabkan oleh Meloidogyne spp. merupakan
penyakit penting pada tomat. Kerugian hasil akibat Meloidogyne spp. di dunia bervariasi untuk
setiap negara sekitar 24-46,2%. Budidaya pertanian intensif di wilayah sentra pertanaman
tomat dengan pola tanam solanaceae secara berturut-turut berpotensi terserang NBA sehingga
intensitas penggunaan bahan kimia seperti pupuk dan pestisida sangat tinggi yang berdampak
negatif terhadap kesehatan manusia dan lingkungan.
Kemampuan Meloidogyne spp. sebagai parasit obligat dengan kisaran inang yang luas dan
tahan terhadap cekaman abiotik merupakan faktor penyebab sulitnya dilakukan pengendalian.
Pengendalian Meloidogyne spp. selama ini dilakukan dengan menggunakan nematisida, namun
teknik tersebut belum dapat menuntaskan permasalahan penyakit NBA sehingga perlu dicari
alternatif teknik pengendalian lainnya yang aman. Tujuan penelitian untuk mendapatkan
bakteri rizosfir (indigenous) terseleksi dari beberapa wilayah sentra tomat di Jawa Barat untuk
mengendalikan Meloidogyne spp. dan bagaimana pengaruhnya terhadap pertumbuhan dan
hasil tomat. Penelitian terdiri atas tiga tahapan yaitu: keragaman bakteri rizosfir di wilayah
sentra tomat di Jawa Barat, induksi bakteri rizosfir pada tanaman tomat skala rumah plastik,
uji efektifitas penginduksian bakteri rizosfir pada tanaman tomat untuk mengendalikan
Meloidogyne spp. skala lapangan (non sentra) dan keefektifan isolat bakteri rizosfir dalam
mengendalikan Meloidogyne spp. pada tanaman tomat di wilayah sentra produksi tomat.
Penelitian tahap pertama dilakukan di laboratorium Pusat Ilmu Hayati PAU-ITB. Hasil
eksplorasi dan isolasi dari lima sentra produksi tanaman tomat diperoleh 189 isolat bakteri
rizosfir, sedangkan hasil seleksi diperoleh 18 bakteri rizosfir yang berpotensi sebagai pemacu
pertumbuhan dan menekan serangan Meloidogyne spp. Dari 18 kandidat bakteri terseleksi
kemudian dilakukan uji kompatibilitas dan hipersensitif diperoleh enam isolat bakteri yang
kompatibel yaitu: LM24, LM38, CW222, CN26, CK27, CK212. Selanjutnya ke enam bakteri
tersebut diidentifikasi secara molekuler menggunakan primer 16 sRNA, diperoleh hasil yaitu:
CK212 (Staphylococcus sciuri.), CK27 (Bacillus cereus CK), CN26 (Ochrobactrum sp.),
CW222 (Bacillus cereus CW), LM24 (Bacillus toyonens), LM38 (Bacillus cereus LM).
Penelitian tahap kedua dilaksanakan pada rumah plastik di Tanjungsari dengan metode Split
Root System menggunakan Rancangan Acak Kelompok (RAK) terdiri dari 57 perlakuan dan
diulang dua kali. Hasil uji karakterisasi fungsional menunjukkan keenam isolat bakteri rizosfir
menghasilkan Indole acetic acid (IAA), lima isolat sebagai pelarut fosfat dan empat isolat dapat
memfiksasi N2, uji aktivitas enzim peroksidase, aktivitas kitinase dan protein total serta
kandungan asam jasmonat ditunjukkan perlakuan isolat konsorsium bakteri Bacillus toyonens
+ Ochrobactrum sp+Bacillus cereus CK paling tinggi, sedangkan untuk kandungan etilen
kontrol menunjukkan konsentrasi paling tinggi. Isolat konsorsium bakteri: (1) Bacillus
toyonens + Staphylococcus sciuri, (2) Bacillus toyonens + Bacillus cereus LM + Bacillus
cereus CW + Staphylococcus sciuri, (3) Bacillus cereus LM + Ochrobactrum sp + Bacillus
cereus CK (4) Bacillus toyonens + Ochrobactrum sp, (5) Bacillus cereus LM + Ochrobactrum
sp + Bacillus cereus CK + Staphylococcus sciuri memberikan pertumbuhan dan hasil tomat
yang lebih baik, sedangkan isolat konsorsium bakteri: (1) Bacillus cereus LM, (2) Bacillus
toyonens + Ochrobactrum sp + Bacillus cereus CK + Staphylococcus sciuri, (3) Bacillus
toyonens + Ochrobactrum sp + Bacillus cereus CK, (4) Bacillus cereus LM + Bacillus cereus
CK mampu menekan serangan Meloidogyne spp.,
Penelitian tahap ketiga dilakukan di dua lokasi, non sentra tomat (Tanjungsari) dan sentra tomat
(Balai Penelitian Tanaman Sayuran Lembang) keduanya menggunakan Rancangan Acak
Kelompok (RAK) yang terdiri dari sepuluh perlakuan dan masing-masing diulang sebanyak 9
dan 10 kali. Hasil pada non sentra menunjukkan perlakuan konsorsium Bacillus toyonens +
Ochrobactrum sp + Bacillus cereus CK, pertumbuhan tanaman, hasil tomat dan penekanan
serangan Meloidogyne spp. lebih tinggi dibanding perlakuan lainnya. Pada lokasi sentra tomat,
hasil menunjukkan untuk kultivar Ratna perlakuan Bacillus toyonens + Ochrobactrum sp +
Bacillus cereus CK dan untuk kultivar Permata perlakuan Bacillus toyonens + Ochrobactrum
sp memberikan pertumbuhan tanaman, hasil buah serta penekanan insiden Meloidogyne spp.
lebih baik. Secara keseluruhan dari hasil penelitian disimpulkan bahwa isolat konsorsium
Bacillus toyonens + Ochrobactrum sp + Bacillus cereus CK dapat menekan serangan
Meloidogyne spp. dan meningkatkan hasil tomat, sehingga isolat konsorsium tersebut
berpotensi untuk dikembangkan sebagai PGPR (Plant Growth Promoting Rhizobacteria) untuk
tanaman tomat.
Kata kunci: Tomat, bakteri rizosfir, Meloidogyne spp., ISR, PGPR.
ABSTRACT
INDUCED RHIZOSPHERE BACTERIA ON TOMATO PLANT
TO CONTROL ROOT-KNOT NEMATODE (Meloidogyne spp.)
By
RIKA ALFIANNY
NIM: 306110023
(Doctoral Study Program of Biology)
Root Knot Nematode (RKN) disease caused by Meloidogyne spp. is an important disease in
tomato. Yield losses due Meloidogyne spp. vary around 24-46,2% world wide. Intensive
cultivation of solanaceae in the central production tomato area is potentially affected by RKN
which causes very high use of fertilizers and pesticides, and give a negative impact on human
health and the environment.
Meloidogyne spp.is hard to control since it is an obligate parasites with a wide range of host
and it is also resistant to abiotic stress factors. Conventional management of Meloidogyne spp.
is carried out by using nematicides, however these techniques can’t resolve the problems of
RKN disease. Accordingly, it is necessary to find alternative and safe desease techniques. The
objective of the study is to isolate indigenous rhizosphere bacteria selected from some of the
central production area of tomato plants in West Java to control Meloidogyne spp. and to study
how othese rhizosphere bacteria affect the growth and yield of tomatoes.This research consists
of three stages, namely rhizosphere bacteria diversity in the central production area of tomato
plantsin West Java,induced rhizosphere bacteria on tomatoes plants plastic house scale, the
effectiveness of induced rhizosphere bacteria on tomato plants to control Meloidogyne spp.
field scale (in central production area of tomato or not).
The first stage of the research was conducted the Central Laboratory of Biological Sciences
PAU-ITB. From the exploration results and isolation from the central production area of
tomato plants in West Java, was obtained 189 rhizosphere bacteria isolates. From the selection
process, 18 isolates showed a potential of enhancing growth and suppress the attack
Meloidogyne spp., compatibility and hypersensitivity tests showed that six of the 18 candidates
isolates were compatible with namely: LM24, LM38, CW222, CN26, CK27, CK212.
Furthermore, these six isolates were identified using 16S rRNA sequencing and the result were
as follow: CK212 (Staphylococcus sciuri), CK27 (Bacillus cereus CK), CN26 (Ochrobactrum
sp.), CW222 (Bacillus cereus CW), LM24 (Bacillus toyonens), LM38 (Bacillus cereus LM).
The second stage of the research was conducted in a plastic house in Tanjungsari using Split
Root System. Research was done using Randomized Block Design (RBD) comprising of 57
treatmentswith two replications.The results showed functional characterization the all
rhizosphere bacteria could be produced indole acetic acid (IAA), five isolates were phosphate
solubilizing bacteria and four isolates could fix (N2) nitrogen. The consortia consisting of
Bacillus toyonens + Ochrobactrum sp. + Bacillus cereus CK showed the best results for
peroxidase activity, chitinase activity, protein total and jasmonic acid concentrations. On the
other hand, according to GCMS results, the highest ethylene concentration was found in the
control. The consortia: (1) Bacillus toyonens + Staphylococcus sciuri,(2) Bacillus cereus LM
+ Ochrobactrum sp + Bacillus cereus CK (3) Bacillus toyonens + Bacillus cereus LM +
Bacillus cereus CW + Staphylococcus sciuri, (4) Bacillus toyonens + Ochrobactrum sp, (5)
Bacillus cereus LM + Ochrobactrum sp + Bacillus cereus CK + Staphylococcus sciuri
enhanced the growth and yield of tomatoes compared to control and other isolate consortium
tested. Additionally, bacterial consortium isolates: (1) Bacillus toyonens + Ochrobactrum sp
+ Bacillus cereus CK + Staphylococcus sciuri, (2) Bacillus cereus LM, (3) Bacillus cereus LM
+ Bacillus cereus CK, (4) Bacillus toyonens + Ochrobactrum sp + Bacillus cereus CK were
able to suppress Meloidogyne spp attack better than control and other treatments.
The third stage of the research was conducted at two locations, the first experimental
plantation was in Tanjungsari using Randomized Block Design (RBD) with ten treatments and
repeated nine times. The results showed that consortium Bacillus toyonens+ Ochrobactrum
sp+ Bacillus cereus CK increased the growth and yield of tomatoes and suppressed the attack
of Meloidogyne spp higher and better if compared to the control and other treatments.The
location of the second study was conducted in the Indonesian Vegetable Research Institute
Lembang. This study was designed using a Randomized Block Design (RBD) consisting of ten
treatments and repeated ten times. Treatment of Ratna cultivars using Bacillus toyonens +
Ochrobactrum sp + Bacillus cereus (CK) consortiashowed higher growth and yield, also lower
nematode incidence compared to control and other treatments. Treatments of Permata
cultivars using Bacillus toyonens + Ochrobactrum sp contortia showed higher growth and
yield and also lower nematode incidence compared to control and other treatments.
Overall results showed that consortia isolates Bacillus toyonens + Ochrobactrum sp + Bacillus
cereus (CK) was potential to PGPR on tomatoes plant. Thus it was to be developed as
biological control agent root knot nematode disease.
Keyword: Tomato, rhizosphere bacteria, Meloidogyne spp., ISR, PGPR.