Judul: Molecular Characterization of Resistance Banana Cultivars to Panama Wilt Disease Caused by Fusarium oxysporum f.sp. cubense
Abstrak: Sustainability of banana and plantain in Indonesia encounters the development of banana pests and diseases that dramatically decreased national banana production. Panama wilt disease caused by Fusarium oxysporum f.sp. cubense (FOC) is one of major banana diseases that infected almost all of banana plantation in Indonesia. A series of experiments were carried out to isolate, characterize resistance gene analogues (RGAs) and defense gene analogues (DGAs), and to develop molecular markers for disease resistance against fusarium wilt. The experiment was started by the assessment of resistance banana cultivars against FOC tropical race-4 (TR4), and selected two cultivars showed resistant to FOC i.e. Calcuta-4 and Klutuk Wulung. From those selected cultivars and one resistant cultivar, Rejang, 17 RGAs were isolated and characterized and showed high sequence identity to NBS-LRR. The RGA sequences were designated as MNBS1-MNBS17. Based on phylogenetic analysis, the RGAs were classified into four groups. First group contained 14 RGA sequences (MNBS1-MNBS14), and the other three groups contained one sequence MNBS15, MNBS16, and MNBS17, respectively. The isolation and characterization of DGA (chitinase and β-1,3-glucanase genes) were carried out using local banana cultivars. Eight putative chitinase sequences (586 bp in length) were isolated from Rejang, Klutuk Wulung, Kepok, Ambon Hijau and Barangan. The sequences were showed high identity (90 %) to banana class II chitinase gene and coded by MaChi. Four putative β-1,3- glucanase sequences (788 bp in length) were isolated and characterized from Rejang, Klutuk Wulung, Ambon Hijau and Barangan. The sequences shared 99 % identity to banana β-1,3-glucanase, and designated as MaGlu. Based on SNP identification, it was revealed that RGA sequences from Rejang (MNBS2-MNBS5) and Calcuta-4 (MNBS6-MNBS14) contained 16 and 9 putative SNPs, respectively. Based on SNP analysis, RGA sequences of Rejang and Calcuta-4 generated 4 and 8 haplotypes, respectively. Twenty two SNPs were identified from 8 chitinase fragments and generated 8 haplotypes, while 8 putative SNPs were identified from 4 β-1,3-glucanase fragments and generated 4 haplotypes. SNAP markers were developed based on non synonymous SNPs identified from RGA (MNBS) and DGA (chitinase and β-1,3-glucanase) sequences. Using PCR technique and allel specific primers approaches, 7 loci based on RGA and DGA sequences were selected as SNAP markers for FOC resistance banana cultivars, there were SNP4_MNBS, SNP2_MChi, SNP6_MChi, SNP8_MChi, SNP10_MChi, SNP11_MChi, and SNP1_MGlu. However, the use of SNP1_MGlu locus can be omitted, because without SNP1_MGlu primers, the grouping of banana cultivar base on FOC resistance will be better.
Keyword: DGA, haplotype, RGA, SNP, SNAP marker

Judul: Molecular Based Classification and Phylogenetic Analysis of Indonesian Banana Cultivars
Abstrak: Banana cultivars are complex hybrids and have been further modified by various mutations. The specific ancestor of the cultivars was difficult to be elucidated. Therefore, the taxonomic status and nomenclature have long been a complicated issue. The goals of the study were to characterize banana accessions from various regions in Indonesia based on microsatellite markers to obtain classification which is stable and accurate and to elucidate phylogenetic relationships of banana cultivars inferred from trnL-F intergenic spacer of cpDNA. The study was conducted using 151 accessions that have been morphologically classified and unclassified 116 accessions. Thirty nine accessions which represented various genomic groups and 12 sequences of different taxa of Musa downloaded from GenBank were used for phylogenetic analysis. Banana accessions were characterized using 12 microsatellite primers. Only 8 primers: MaCIR108; MaCIR332a; MaCIR327b; Ma-1-17; Ma-1-27; Ma-1-132; Ma-3-90; and Ma-3-139 produced clear alleles and exhibited polymorphic banding patterns. Total 267 banana accessions were effectively classified into 3 species based only on: 4 alleles of MaCIR108 with the size of more than 270 bp; alleles of MaCIR108 with the size of 270 bp or less; and 1 allele of Ma-3-90 with the size of 152 bp. There are 130 accessions of AA or AAA; and AAA designated under Musa acuminata, 10 accessions of BB designated under M. balbisiana, 64 accessions of AAB and 63 accessions of ABB designated under hybrid species M. x paradisiaca. Eleven accessions of pure the A genome and 9 accessions containing the B genome previously identified based on morphology have been reclassified into M. x paradisiaca and M. acuminata. The study also exhibited that microsatellites are an effective marker for identifying banana cultivars. Analysis of 267 banana accessions using the 8 primers detected only 208 genotypes because 88 accessions formed 29 identical genotypes. In general, the banana accessions clustered according to their genomic groups, except 15 accessions of AAB; accessions of AA or AAA; and AAA. In the phylogeny inferred from the trnL-F region, 40 accessions having the A-type chloroplast consisting of AA wild; AA; AA or AAA; AAA; AAB; and ABB cultivars were clearly differentiated from 11 accessions having the B-type chloroplast consisting of BB, AAB, and ABB cultivars. The A-type chloroplast accessions are most probably derived from female M. acuminata, while those with the B-type chloroplast may be derived from female M. balbisiana. However, the specific acuminata ancestor of each cultivar remains unidentified. Genetic relationships among banana accessions based on the trnL-F region are not in agreement with those based on the microsatellite most probably due to the differences of inheritance mode of both DNA markers.
Keyword: Genetic analysis diversity, Microsatelite, Filogeni, trnL-F Intergenic Spacer

Judul: Penyelesaian Masalah Rotasi Aliran Fluida Kental Von Karman Menggunakan Metode Homotopi
Abstrak: Von Karman equation is an equation that describes fluid viscous flow induced by infinite disk rotation. By assuming steady flow and laminar, viscous incompressible fluid flow is represented in Von Karman equation by an angular velocity and the vertical direction velocity as the independent variables. Von Karman equation is a nonlinear problem that is solved using the homotopy method. The use of homotopy method is done by defining an homotopy function that requires auxiliary parameters to control the convergent region of the solution. The solution is a recursive formula with given initial conditions. Using software based-functional shows that velocity components converge to a value.
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