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To overcome the negative impact of the fungicide application, RB gene, originated from Solanum bulbocastanum, a resistance gene to the disease has been introduced to the genome of potato plant Katahdin, which was later named as Katahdin SP951. The aims of the research were to confirm the RB gene in the genetically modified plant (GMP) Katahdin SP951 through resequencing the RB gene in the Katahdin SP951 genome and to align the RB genes isolated from the transgenic Katahdin SP951 and the cloning vector pLCD0454, which was used the vector to transform Katahdin cultivar. The RB gene has high similarity to other resistance genes in potato plants, and therefore nontransgenic Katahdin, and Solanum bulbocastanum were used in the analysis as the negative and positive control, respectively. Seven pairs of specific primers, which could differentiate the RB gene were used for gene sequencing studies. The sequencing experiments obtained 2913 bases which showed 100% similarity to the RB sequence isolated from the pLCD04541 plasmid. It is concluded that the RB gene in the Katahdin SP951 did not experience mutation during transformation process and integration into the Katahdin genome.Keywords: RB gene, potato, sequence confirmation. ABSTRAKPenanaman kentang transgenik dapat mengurangi penggunaan fungisida. Gen RB, yang merupakan gen ketahanan terhadap patogen penyakit hawar daun (Phytophthora infestans), telah berhasil diisolasi dari tanaman kentang liar S. bulbocastanum dan disisipkan ke dalam genom tanaman kentang varietas Katahdin, yang kemudian dinamai klon Katahdin SP951. Penelitian ini bertujuan mengonfirmasi keberadaan gen RB dalam genom tanaman kentang transgenik Katahdin SP951 dengan cara menyekuen gen tersebut dari tanaman kentang Katahdin SP951, dan kemudian membandingkannya dengan sekuen gen RB dari plasmid pCLD04541 yang digunakan untuk mentransformasi Katahdin dan mengandung gen RB. Katahdin nontransgenik dan S. bulbocastanum secara berurutan digunakan sebagai kontrol negatif dan positif. Hasil PCR mendapatkan tujuh primer yang spesifik terhadap gen RB dan kemudian digunakan untuk sekuensing. Hasil sekuensing berupa urutan DNA sepanjang 2.913 basa yang memiliki kesamaan 100% dengan urutan gen RB pada plasmid pCLD04541. Dapat disimpulkan bahwa gen RB tidak mengalami mutasi, baik dalam proses transformasi maupun pada waktu integrasi ke dalam genom kentang varietas Katahdin.Kata kunci: Gen RB, kentang, konfirmasi sekuen.

Development of potato cultivars with high levels of broad spectrum resistance is a key long-term management strategy against late blight disease caused by Phytophthora infestans. Six progeny lines of hybridization between transgenic potato Katahdin SP951 with non-transgenic Granola and Atlantic were selected based on agronomical characteristics and resistance to late blight disease. The study aimed to analyze the number of insertions and stability of inserted RB gene in the transgenic potato lines. The research was carried out through plant DNA extraction, southern blot analysis and polymerase chain reaction (PCR). Southern blot analysis was used to detect the number of inserts integrated into potato genome, while PCR analysis was used to detect stability of RB gene from generation to generation. The results showed that the progenies obtained from hybridization between Atlantic and transgenic Katahdin SP951 (lines No. 20 and 27) and between Granola and transgenic Katahdin SP951 (line No. 69) contained one copy number of RB gene, according to the probing of nptII. The result is similar to that of inserted RB gene found in the parental transgenic Katahdin SP951. The presence of RB gene in four different generations (G0, G1, G2 and G3) showed stable integration of the gene into the plant genome. The single copy number of RB gene will repress the occurrence of silencing gene expression. The stability analysis of RB gene can determine that the gene is still present in plant genome after several generations.

Padi merupakan tanaman pangan penting di dunia dan lebih dari 40% penduduk dunia memanfaatkan padi sebagai makanan pokok. Salah satu faktor yang terlibat pada pertumbuhan dan produktivitas padi adalah kebutuhan nutrien dan salah satu unsur penting adalah nitrogen (Shakouri et al., 2012). Beberapa dekade yang lalu, pemanfaatan pupuk kimia merupakan jalan pintas untuk peningkatan pertumbuhan tanaman. Namun demikian, akhir-akhir ini penggunaan pupuk kimia telah mengalami penurunan karena dampak negatif yang ditimbulkan dan mulai bergeser ke penggunaan pupuk hayati yang ramah lingkungan (Bashan dan Holquin, 1998; Roy dan Srivastava, 2010). Penggunaan mikroba tanah yang hidup di rhizosfir tanaman

Biomass from lignocellulosic wastes is a potential source for biobased products. However, one of the constraints in utilization of biomass hydrolysate is the presence of inhibitors. Therefore, the use of inhibitor-tolerant microorganisms in the fermentation is required. The study aimed to investigate the effect of a mixture of inhibitors on the growth of Saccharomyces cerevisiae strain I136 grown in medium containing synthetic inhibitors (acetic acid, formic acid, furfural, 5-hydroxymethyl furfural/5-HMF, and levulinic acid) in four different concentrations with a mixture of carbon sources, glucose (50 g.l -1 ) and xylose (50 g.l -1 ) at 30 o C. The parameters related to growth and fermentation products were observed. Results showed that the strain was able to grow in media containing natural inhibitors (BSL medium) with µmax of 0.020/h. Higher level of synthetic inhibitors prolonged the lag phase, decreased the cell biomass and ethanol production, and specific growth rate. The strain could detoxify furfural and 5-HMF and produced the highest ethanol (Y(p/s) of 0.32 g.g -1 ) when grown in BSL. Glucose was utilized as its level decreased in a result of increase in cell biomass, in contrast to xylose which was not consumed. The highest cell biomass was produced in YNB with Y (x/s) value of 0.25 g.g -1 . The strain produced acetic acid as a dominant side product and could convert furfural into a less toxic compound, hydroxyl furfural. This robust tolerant strain provides basic information on resistance mechanism and would be usefull for bio-based cell factory using lignocellulosic materials.

Modern agriculture rellies on the application of fertilizer to enhanched plant growth. Excessive application of chemical fertilizers in the long term will decrease soil fertility, therefore the use of biological fertilizers is expected to reduce the negative impact. The aim of this study was to determine the effect of multi-functional Azospirillum for N2-fixation, phosphate solubilizer  and producing phytohormone Indole Acetic Acid (IAA) on the growth of rice plants Ciherang in the pot experiment conducted in the BB Biogen’s greenhouse. Two treatments were tested: types of inoculation (not inoculated, were inoculated with the wildtype AjB 6.4.1.2 and inoculated with mutant isolates AJM 3.7.1.14), and 4 levels of fertilizer application (not fertilized, a quarter dose of paddy fertilizer recommendations, a half dose of fertilizer rice in the rice fields, and the appropriate dose of fertilizer in paddy fields). Azospirillum used is wildtype isolate AjB 6.4.1.2 and mutant isolate AJM 3.7.1.14 isolated and and mutated in BB Biogen. Ciherang rice seed inoculated with Azospirillum on the cell density of 106 cells / ml at the different seedlings tub. After the age of 14 days after planting, the seedlings were transferred into pots with three plants per pot. Parameters measured were: plant height, number of tillers, number of panicles per clump, fresh weight and dry panicles per clump, weight of 100 grains, and the content of N and P stover. Results show that inoculantion, affect significantly on the number of panicles per hill, grain weight per panicle and the dry weight of grains per panicle.

Late blight caused by Phytophthora infestans is an important disease on potato.  Several potato hybrids have been generated by crossing local varieties (Atlantic and Granola) with Katahdin SP951 which contains late blight resistance gene RB.  Prior to release, these hybrids need to be evaluated for their environ-mental effects on non-target organisms and natural pests and diseases. The objectives of the study were to investigate the effect of LBR potato hybrids on beneficial soil microbes, pests and diseases. The trial was conducted in the confined field trial (CFT) in Lembang, West Java. The parental non-transgenic (NT) clones (Granola, Atlantic and Katahdin) and LBR hybrids (four clones of Atlantic x Katahdin SP951 hybrids; 10 clones of Granola x Katahdin SP951) were planted at a plant spacing of 30 cm x 70 cm. Fungicide applications were used as treat-ments (no spray, five and twenty times sprays). The experi-ment was arranged in a randomized completely block design with three replications. The parameters determined were popula-tions of N2 fixing and P solubilizing bacteria, soil C/N ratio as well as natural pests and diseases. The results showed that the transgenic LBR potato hybrids did not have negative effect on N fixing bacteria. The bacterial populations were around 1010-11 cells g-1 soil before planting, 1012 cells at 1.5 months after planting (MAP) and 108 cells after harvest. For P- solubilizing bacteria, their populations were 1010 cells before planting, 1012 cells at 1.5 MAP and 1011 cells g-1  soil after harvest. The soil C/N ratio of the transgenic plot was not statistically different compared to non-transgenic plot, i.e. 12-15 before planting, 10-11 at 1.5 MAP, and 10 after harvest in non-spray plot. Pests and diseases such as Alternaria solani, Liriomyza, potato tubber moth, aphid and mites on the transgenic and non-transgenic plots were statistically not different. The resistance score for A. solani was 7.2 (parental tansgenic) and 7.6 (parental non-transgenic); for Liriomyza it was 2.07 (parental transgenic) and 2.32 insect per plant (parental non-transgenic), the PTM was 0.63 (parental transgenic) and 0.73 insect per plant (parental non-transgenic), aphid and mites were 0.75 (parental transgenic) and 1.68 insects per plant (parental non-transgenic). The study indicated that LBR potato hybrids did not have any negative impacts on non-target organisms.