Seleksi in Vitro Dan Pengujian Mutan Tanaman Pisang Ambon Kuning Untuk Ketahanan Terhadap Penyakit Layu Fusarium

Fusarium wilt of banana (Musa spp.) caused byFusarium oxysporum f. sp. cubense (Foc) is the most seriousproblem faced in banana cultivation in terms of plantproductivity and fruit quality. Mutation breeding is one of thealternative method that can be applied in producing newbanana cultivar. Mutants can be induced by chemicalmutagen such as ethyl methane sulfonate (EMS) followed byin vitro selection and then evaluation of the mutants tofusarium wilt disease in glasshouse and Foc infected field.The aim of this research was obtained EMS induced and invitro selected mutants of banana var. Ambon Kuning andevaluated Foc disease resistant clones in glasshouse andFoc infected field. The first step to obtain the explants forthis research was initiation and formation of multiple budclumps (MBC) using MS basal media supplemented with 5,10, and 20 mg/l of benzyladenin. Plant regeneration of MBCwas also studied by using MS media containing 0, 0.2, and 1mg/l of benzyladenin. To induce mutagenesis, MBC wassoaked in 0.1, 0.3, and 0.5% (v/v) EMS for 1, 2, and 3 hours.The assesment of resistant MBC mutants to Fusariumphytotoxin was conducted by using fusaric acid (FA) asselection agent in concentration of 30, 45, and 60 ppm.Putative mutant plants produced by in vitro selection werefurther tested using spore solution of Foc race 4 inglasshouse. Meanwhile, Foc resistance assesment in theinfected field was conducted in Pasirkuda ExperimentalStation, Bogor Agricultural University. The results showedthat MBC can be formed in MS basal media supplementedwith 10 or 20 mg/l benzyladenin. The EMS played a role inobtaining mutants by producing 68 MBC putative mutantstolerant to Foc based on FA selection. Further evaluation inthe glasshouse was obtained 64 Foc resistant plants from391 putative mutants produced by in vitro selection.Evaluation in the Foc infected field showed six clonessurvived until generative phase (12 month of age)

Resistance and Phenotypic Character of Chili M2 Mutant Lines Against Chilli Veinal Mottle Virus

Chilli veinal mottle virus infection (ChiVMV) could reduce the quality and 60–100% of yield losses of Chili. Among the Chilivarieties released, no one has been resistant to ChiVMV, mainly due to a high variation of ChiVMV strains and not well mapped.Therefore, finding a new source of ChiVMV resistant genes is pivotal role in order to assembly new varieties. Approach throughin vitro mutation induction using mutagen ethyl methane sulfonate (EMS) is one of the efforts to increase genetic diversity.Previous studies has successfully acquired 800 M2 lines through callus induction of Gelora variety with EMS. This study aimed toobtain M2 lines resistant to ChiVMV and having a good agronomical characters. A total of 800 Chili M2 lines that derived from ChiliM2 mutations using mutagen EMS has been tested in greenhouse to ChiVMV resistance and studied character phenotype. Theresults showed that of the 800 lines, there were 28 strains obtained showed a response tolerant and resistant to ChiVMV. Eightmutant lines of which have good agronomic characters. The mutant lines are M2.100, M2.108, M2.200, M2. 122, M2.238, M2.353,M2.420, and M2.517. Eight lines will be selected and further observed to obtain Chili promising lines that are resistant to ChiVMVand high yielding

Isolasi, Identifikasi, dan Karakterisasi Cendawan Blas Pyricularia Oryzae Hasil Rejuvenasi

Penyakit blas yang disebabkan oleh cendawan Pyricularia oryzae (Po) merupakan salah satu penyakit penting pada pertanaman padi di Indonesia. Penelitian ini bertujuan untuk mendapatkan cendawan patogen blas yang berasal dari hasil rejuvenasi simpanan benih, media agar, dan jaringan daun padi. Selain itu, identifikasi koleksi isolat blas yang ditujukan untuk penyimpanan jangka panjang dan karakterisasi kespesifikan tiap isolat terhadap lokus spesifik gen virulensi. Hasil pengujian menunjukkan 22,7% isolat yang tersimpan dalam media agar masih menunjukkan tipikal miselium Po. Kespesifikan pola pita DNA genomik total isolat yang dianalisis berdasarkan primer penyandi gen spesifik virulensi Cut1, Erg2, dan Pwl2, diperoleh sebanyak enam haplotipe meliputi B-001 (1 isolat), C-011 (1 isolat), D-111 (8 isolat), F-110 (1 isolat), G-100 (3 isolat), dan H-101 (2 isolat). Tidak ditemukan haplotipe A-000 dan E-010 pada isolat Po yang dianalisis. Dalam hubungannnya dengan patogenisitas, mayoritas cendawan Po mempunyai gen Cut1, Pwl2, dan Erg2. Di antara total isolat cendawan Po, gen yang paling besar ditemukan proporsinya adalah gen Pwl2 (87,5%) diikuti Cut1 (75%) dan Erg2 (62,4%)

Karakterisasi dan Identifikasi Isolat Bakteri Endofitik Penghambat Jamur Patogen Padi

Disease caused byfungal pathogens often causing damage on rice crop. Thisstudy was aimed to characterize 10 endohytic bacterial isolatesin suppression of rice pathogenic fungi. Characterization by invitro test showed several endophytic isolates effective againstfungal pathogen Rhizoctonia solani (Rs) and Pyriculariaoryzae (Po). The bacterial culture filtrates could inhibit radialgrowth of fungal colonies with the Rs ranged percentageinhibition of 32.9-99.4%, whilst inhibition against Po wereranged from 3-98.2%, respectively. Based on chitinase assay,it was indicated that gram negative bacteria of E 76 isolateproduced clear zone and highest chitinolytic index. Theanalysis to the base sequence (total 1,322 bp) using 16s rRNAgene sequencing revealed that E76 isolates had 99% similaritywith Burkholderia sp

Control of Anthracnose Disease (Colletotrichum Gloeosporioides) Using Nano Chitosan Hydrolyzed by Chitinase Derived From Burkholderia Cepacia Isolate E76

Anthracnose (Colletotrichum gloeosporioides) is one of the important diseases of fruit crops that need to be controlled. This study was aimed to obtain the best formula of hydrolyzed nano chitosan and its potensial in controlling anthracnose. The hydrolyzed chitosan was prepared using chitinase enzyme extracted from Burkholderia cepacia isolate E76. Chitosan nanoparticles were synthesized using ionic gelation method by reacting hydrolyzed chitosan (0.2%) with Sodium tripolyphosphate (STPP) (0.1%) as cross-linking agent using 30–60 minutes stirring condition. The bioactivity of the nano chitosan formula was tested to C. gloeosporioides under in vitro and in vivo assays. The specific enzymatic activity of the purified chitinase was higher (0.19 U/mg) than that of crude enzyme (supernatant) with the purity increased by 3.8 times. Of the four formula tested, Formula A (hydrolyzed chitosan to STPP volume ratio of 5 : 1 with 60 minutes stirring condition) was found good in terms of physical characteristic of the particle. The formula nano chitosan particle had the spherical-like shape with an average particle size of 126.2+3.8 nm, polydispersity index (PI) of 0.4+0.02, and zeta potential (ZP) value of 27.8+0.2 mV. Nano chitosan had an inhibitory activity to C. gloeosporioides in vitro up to 85.7%. Moreover, it could inhibit 61.2% of C. gloeosporioides spores germination. It was shown that nano chitosan was also effective to reduce anthracnose disease severity in vivo when applied as a preventive measure on Chili and papaya fruits. This study could be used as a reference for further fruit coating application using nano chitosan as a promising postharvest biocontrol agent to C. gloeosporioides

Keragaman Genetik Rizobakteri Penghasil Asam Indol Asetat Berdasarkan 16S RRNA dan Amplified Ribosomal DNA Restriction Analysis

Asam indol asetat (AIA) dapat dihasilkan oleh bakteri rizosfer/rizobakteri pemacu pertumbuhan tanaman (PPT). Keragaman genetik isolat bakteri PPT indigenous Indonesia perlu diinvestigasi untuk mencari sumber potensial agen PPT dengan informasi kekerabatan intra dan interspesies yang jelas. Karena itu penelitian ini bertujuan mengetahui keragaman genetik rizobakteri penghasil AIA indigenous Indonesia dengan gen 16S rRNA, dilengkapi dengan ARDRA. Koleksi isolat bakteri BB Biogen diidentifikasi kandungan AIA-nya, morfologi secara makroskopis dan sekuensing pada sekuen 16S rRNA dan ARDRA. Total empat belas isolat rizobakteri memiliki kandungan AIA dalam kisaran 5,24-37,69 µg/ml dan tertinggi pada SM1. Karakteristik morfologi koloni rizobakteri mendukung variasi strain bakteri penghasil AIA. Delapan isolat terpilih diidentifikasi sebagai spesies Bacillus dengan homologi 96-99%. Lima isolat (SM1, JP4, KP3, MB2, dan CP3) diidentifikasikan sebagai B. subtilis, SC2 sebagai B. amyloliquefaciens, BL2 dekat dengan B. velezensis, dan JP3 memiliki homologi tinggi dengan Brevundimonas olei. Delapan isolat rizobakteri tersebut berkerabat dekat dengan strain bakteri referensi yang memiliki kesamaan spesies. Analisis ARDRA-RsaI menghasilkan lima filotipe dengan keunikan pola sidik jari. Isolat CP3, MB 2, dan KP 3 berada dalam satu filotipe. Kedekatan isolat dalam Bacillus sp. digambarkan oleh filotipe 5 (B. subtilis SM1 dan B. velezensis BL2) yang diduga jauh dari B. amyloliquefaciens SC2 (filotipe 4) dan JP 3 pada genus Brevundimonas (filotipe 3). Keragaman genetik isolat rizobakteri penghasil AIA terhitung rendah berdasarkan 16S-rRNA dan ARDRA-RsaI