Ahmad Warsun
Indonesian Center for Agricultural Biotechnology and Genetic Resources Research and Development, Jl. Tentara Pelajar 3A, Bogor 16111 Phone (62-251) 8337975

Published : 8 Documents
Articles

Found 8 Documents
Search

IDENTIFICATION OF A MAJOR QUANTITATIVE TRAIT LOCUS CONFERRING RICE BLAST RESISTANCE USING RECOMBINANT INBRED LINES

Indonesian Journal of Agricultural Science Vol 11, No 1 (2010): April 2010
Publisher : Indonesian Agency for Agricultural Research and Development - MOA

Show Abstract | Original Source | Check in Google Scholar

Abstract

Blast disease caused by Pyricularia oryzae is one of the limitingfactors for rice production world wide. The use of resistantvarieties for managing blast disease is considered as the mosteco-friendly approaches. However, their resistances may bebroken down within a few years due to the appearance of newvirulent blast races in the field. The objective of the presentstudy was to identify the quantitative trait locus (QTL) conferringresistance to blast disease using 126 recombinant inbred(RI) lines originated from a crossing of a durably resistant uplandrice genotype (Laka) and a highly susceptible rice accessioncultivar (Kencana Bali). The RI population was developedthrough a single seed descent method from 1997 to 2004.Resistance of the RI lines was evaluated for blast in an endemicarea of Sukabumi, West Java, in 2005. Disease intensity of theblast was examined following the standard evaluation systemdeveloped by the International Rice Research Institute (IRRI).At the same year the RI lines were analyzed with 134 DNAmarkers. Results of the study showed that one major QTL wasfound to be associated with blast resistance, and this QTL waslocated near RM2136 marker on the long arm of chromosome11. This QTL explained 87% of the phenotypic variation with37% additive effect. The map position of this QTL differedfrom that of a partial resistant gene, Pi34, identified previouslyon chromosome 11 in the Japanese durably resistant variety,Chubu 32. The QTL, however, was almost at the same positionas that of the multiple allele-resistant gene, Pik. Therefore, anallelic test should be conducted to clarify the allelic relationshipbetween QTL identified in this study and the Pik. The RI linesare the permanent segregating population that could be veryuseful for analysing phenotypic variations of important agronomictraits possibly owned by the RI lines. The major QTLidentified in this study could be used as a genetic resource inimprovement of rice varieties for blast resistance in Indonesia

Phylogenetic and Maturity Analyses of Sixty Soybean Genotypes Used for DNA Marker Development of Early Maturity Quantitative Trait Loci in Soybean

Jurnal AgroBiogen Vol 7, No 1 (2011): Jurnal AgroBiogen
Publisher : Jurnal AgroBiogen

Show Abstract | Original Source | Check in Google Scholar

Abstract

The Indonesian soybean productivity is still very low with the national average of 1.3 t/ha. One means to improve national soybean productivity is by manipulating harvest index by cultivating very early maturing soybean cultivars. Development of early maturing soybean cultivars can be expedited by using marker-aided selection. The objective of this study was to select parental lines having contrasted maturity traits and selected parents must be genetically distance. The parents then were used to develop F2 populations for detecting early maturity QTL in soybean. Maturity tests of 60 soybean genotypes were conducted at two locations, Cikeumeuh (Bogor) and Pacet (Cianjur) using a randomized block design with three replications. Genomic DNA of the 60 genotypes were analyzed using 18 SSR markers and genetic relationship was constructed using the Unweighted Pair-Group Method Arithmatic through Numerical Taxonomy and Multivariate System program version 2.1-pc. Results showed that the 60 genotypes demonstrated normal distribution in both locations for days to R1 (32-48d), days to R3 (35-55d), days to R7 (75-92d), and days to R8 (78-99d). Four early maturing genotypes and three late genotypes were obtained. Total SSR alleles observed were 237 with average allele per locus of 12.6 (3-29), and average PIC value of 0.78 (0.55-0.89). Genetic similarity among genotypes ranges from 74.8-95%. At similarity level 77% divided the genotypes into six clusters (the four selected early maturing genotypes located in clusters III and IV, while the three late genotypes located in cluster II). Based on maturity data, pubescent color, and phygenetic analysis seven parents were selected (four early maturing genotypes B1430, B2973, B3611, B4433 and three late genotypes B1635, B1658, and B3570). Twelve F2 populations were developed with the aid of SSR markers Satt300 dan Satt516. Two of the populations will be used to develop DNA markers for earliness in soybean.

Perbedaan Genetik Tanaman Padi Kultivar Asahan, Kencana Bali dan Laka Berdasar dari 127 Marka RFLP

Zuriat Vol 13, No 2 (2002)
Publisher : Zuriat

Show Abstract | Original Source | Check in Google Scholar

Abstract

Perbedaan genetik tanaman padi kultivar Asahan, Kencana Bali dan Laka telah dianalisa dengan menggunakan 127 marka RFLP (Restriction Fragment Length Polimorphism) yang tersebar di 12 kromosom padi. Asahan dan Laka adalah Kultivar yang tahan dan Kencana Bali rentan terhadap serangan cendawan blas, Pyricularia grisea di Indonesia. Pada kombinasi 127 marka RFLP dengan 4 macam enzim restriksi, terdeteksi lebih dari 800 fragment DNA untuk tiap kultivar yang diuji. Berdasarkan pola penampilan fragmen DNA, dihitung jarak genetik (genetic distance) antara ketiga kultivar tersebut. Hasilnya menunjukkan bahwa jarak genetic antara Laka dan Kencana Bali lebih besar daripada jarak genetic antara Asahan dan Kencana Bali. Data ini mengindikasikan bahwa kombinasi atau persilangan antara Laka dengan Kencana Bali akan lebih memberikan kemudahan dalam analisis gen ketahanan blas dengan teknik RFLP dibandingkan dengan kombinasi antara Asahan dengan Kencana Bali.

Genetic Mapping of SSR Markers in Eight Soybean Chromosomes Based on F2 Population B3462 x B3293

Jurnal AgroBiogen Vol 7, No 2 (2011): Oktober
Publisher : Balai Besar Penelitian dan Pengembangan Bioteknologi dan Sumber Daya Genetik Pertanian

Show Abstract | Original Source | Check in Google Scholar | Full PDF (183.856 KB)

Abstract

Genetic Mapping of SSR Markers in Eight SoybeanChromosomes Based on F2 Population B3462 x B3293. IMade Tasma, Ahmad Warsun, Dani Satyawan, SaptowoJ. Pardal, and Slamet. Aluminum toxicity is one of the maincontrains for cultivating soybean in acid soils. GeneticHak Cipta © 2011, BB-Biogenmapping of SSR markers is one step for detecting aluminumtoxicitytolerant QTLs in soybean. Another step is tophenotype the same population at various aluminum-toxicityenvironments. The objectives of this study were to analyzethe segregation of SSR markers in progenies of an F2population and map the markers in 8 soybean chromosomes.The F2 population was previously developed bycrossing the Al-tolerant parent B3462 and the Al-sensitiveparent B3293. Polymorphic SSR markers in the parents wereused to PCR amplify DNA of the 100 F2 progenies. PCRproducts were separated using agarose or polyacrylamidegels. A Chi-Square test was done with a null hypothesis thatprogenies segregated in a 1 : 2 : 1 ratio. Results showed that125 SSR markers were polymorphics in the parents. Out of125 polymorphic markers, 122 were segregated in theprogenies of the F2 population. Among the segregatingmarkers, 114 were segregated in a 1 : 2 : 1 ratio. Only 8markers (5.6%) did not follow the 1 : 2 : 1 ratio. One hundredand nineteen SSR markers were mapped in 8 soybeanchromosomes. These include 18 markers in chromosomeA2, 10 in B1, 16 (C1), 16 (F), 10 (G), 23 (J), 16 (L), and 10 (N).Total genetic maps covered was 1,194.8 cM with averagemap distances between two adjacent markers of 10.7 cM.Further SSR marker enrichment is required to fill in the gapsof several chromosomal regions. Genetic maps presented inthis study should be useful for detection of Al-toxicitytolerant QTLs in soybean.

Genetic Diversity Analysis of Aluminum-toxicity Tolerant and Sensitive Soybean Genotypes Assessed with Microsattelite Markers

Jurnal AgroBiogen Vol 5, No 1 (2009): April
Publisher : Balai Besar Penelitian dan Pengembangan Bioteknologi dan Sumber Daya Genetik Pertanian

Show Abstract | Original Source | Check in Google Scholar | Full PDF (153.217 KB)

Abstract

Analisis Diversitas Genetik Genotipe Kedelai Toleran danPeka Keracunan Aluminium Menggunakan Marka Mikrosatelit.I Made Tasma dan Ahmad Warsun. Persilangandua genotipe kedelai dengan jarak genetik jauh menghasilkanprogeni dengan polimorfisme tinggi pada banyak lokusyang memfasilitasi keberhasilan program pemuliaan dan pemetaankarakter agronomi penting kedelai. Tujuan penelitianini untuk mengetahui diversitas genetik genotipe kedelaitoleran dan peka keracunan aluminium (Al), informasi diversitasalel dan tingkat polimorfisme marka SSR dari genotipekedelai yang diuji, menentukan genotipe dengan jarak genetikjauh sebagai tetua dalam pembentukan populasi pemetaankarakter toleran Al, dan informasi diversitas genetik dalampemilihan tetua untuk program pemuliaan kedelai tolerankeracunan Al. Dua puluh empat genotipe kedelai tolerandan peka keracunan Al dianalisis menggunakan 15 markaSSR. Marka SSR lokasinya menyebar pada 14 kromosom kedelai.Dendrogram dikonstruksi menggunakan UnweightedPair-Group Method Arithmatic (UPGMA) melalui programNumerical Taxonomy and Multivariate System (NTSYS) versi2.1-pc. Diversitas genetik antara dua genotipe kedelai berkisarantara 2-33,2%. Pada diversitas 33,2% uji klaster UPGMAmembagi genotipe menjadi 2 kelompok masing-masing terdiridari 19 dan 5 genotipe untuk kelompok 1 dan 2. Jumlahalel SSR total 81dengan rata-rata jumlah alel per lokus SSR4,4 dan rata-rata tingkat polimorfisme 0,55. Menggunakan diversitastertinggi 33,2% dua genotipe paling peka Al (B3293dan B3442) dari kelompok 1 dan dua genotipe paling toleranAl (B3462 dan B3851) dari kelompok 2 dipilih untuk membentukpopulasi pemetaan karakter toleran Al. Berdasarkannilai diversitas genetik tertinggi 33,2% banyak kemungkinankombinasi persilangan dapat dilakukan antara genotipetoleran Al untuk pemuliaan kedelai toleran Al.

Development and Characterization of F2 Population for Molecular Mapping of Aluminum-Toxicity Tolerant QTL in Soybean

Jurnal AgroBiogen Vol 4, No 1 (2008): April
Publisher : Balai Besar Penelitian dan Pengembangan Bioteknologi dan Sumber Daya Genetik Pertanian

Show Abstract | Original Source | Check in Google Scholar | Full PDF (207.479 KB)

Abstract

Keracunan aluminium merupakan salah satukendala utama dalam budidaya kedelai pada lahan masam.Pembentukan populasi F2 merupakan langkah awal yangmenentukan keberhasilan program pemuliaan tanaman. Tujuanpenelitian ini untuk membentuk dan mengkarakterisasipopulasi F2 hasil persilangan tetua toleran dan tetua pekakeracunan Al. Pembentukan populasi dilakukan menggunakanbantuan marka SSR. Dengan marka SSR populasi dapatdibentuk dengan cepat, akurat, dan efisien. Skrining genotipakedelai pada tanah masam kahat hara menghasilkan duagenotipa toleran dan dua peka. Empat persilangan tunggaldibuat untuk mendapatkan benih F1. Tanaman F1 dan F2 diidentifikasimenggunakam marka SSR Satt_070. Dua populasi(B3462 X B3293 dan B3462 X B3442) dipilih berdasarkansuperiotas fenotipa pada lahan masam dan karakteristik molekulerpasangan tetua. Karakterisasi kedua populasi di lapangmenunjukkan transgresiveness luas untuk karakter reproduksiseperti jumlah polong dan berat 100 biji. Ini mengindikasikanbahwa karakter penting lain selain karakter ketahananterhadap keracunan Al potensial untuk dipetakandari populasi ini. Metoda pembentukan populasi ini akan sangatbermanfaat bagi pemulia tanaman khususnya pemuliakedelai untuk meningkatkan efisiensi program pemuliaanketahanan terhadap keracunan Al.

Phylogenetic and Maturity Analyses of Sixty Soybean Genotypes Used for DNA Marker Development of Early Maturity Quantitative Trait Loci in Soybean

Jurnal AgroBiogen Vol 7, No 1 (2011): April
Publisher : Balai Besar Penelitian dan Pengembangan Bioteknologi dan Sumber Daya Genetik Pertanian

Show Abstract | Original Source | Check in Google Scholar | Full PDF (183.856 KB)

Abstract

Phylogenetic and Maturity Analyses of Sixty SoybeanGenotypes Used for DNA Marker Development of EarlyMaturity Quantitative Trait Loci in Soybean. I MadeTasma, Dani Satyawan, Ahmad Warsun, MuhamadYunus, and Budi Santosa. The Indonesian soybeanproductivity is still very low with the national average of 1.3t/ha. One means to improve national soybean productivity isby manipulating harvest index by cultivating very earlymaturing soybean cultivars. Development of early maturingsoybean cultivars can be expedited by using marker-aidedselection. The objective of this study was to select parentallines having contrasted maturity traits and selected parentsmust be genetically distance. The parents then were used todevelop F2 populations for detecting early maturity QTL insoybean. Maturity tests of 60 soybean genotypes wereconducted at two locations, Cikeumeuh (Bogor) and Pacet(Cianjur) using a randomized block design with threereplications. Genomic DNA of the 60 genotypes wereanalyzed using 18 SSR markers and genetic relationship wasconstructed using the Unweighted Pair-Group MethodArithmatic through Numerical Taxonomy and MultivariateSystem program version 2.1-pc. Results showed that the 60genotypes demonstrated normal distribution in bothlocations for days to R1 (32-48d), days to R3 (35-55d), days toR7 (75-92d), and days to R8 (78-99d). Four early maturinggenotypes and three late genotypes were obtained. TotalSSR alleles observed were 237 with average allele per locusof 12.6 (3-29), and average PIC value of 0.78 (0.55-0.89).Genetic similarity among genotypes ranges from 74.8-95%.At similarity level 77% divided the genotypes into six clusters(the four selected early maturing genotypes located inclusters III and IV, while the three late genotypes located incluster II). Based on maturity data, pubescent color, andphygenetic analysis seven parents were selected (four earlymaturing genotypes B1430, B2973, B3611, B4433 and threelate genotypes B1635, B1658, and B3570). Twelve F2populations were developed with the aid of SSR markersSatt300 dan Satt516. Two of the populations will be used todevelop DNA markers for earliness in soybean.

Mapping of Resistance Genes to Brown Planthopper in Untup Rajab, an Indonesian Local Rice Variety

Jurnal AgroBiogen Vol 14, No 2 (2018): December
Publisher : Balai Besar Penelitian dan Pengembangan Bioteknologi dan Sumber Daya Genetik Pertanian

Show Abstract | Original Source | Check in Google Scholar | Full PDF (701.872 KB)

Abstract

Brown planthopper (BPH) is a major rice pest in Indonesia. The most economical and effective approach to control the insect pest is by using resistant varieties. Exploring for resistance genes is, therefore, a prerequisite for effective breeding program for BPH resistance. This study aimed to map BPH resistance genes in Untup Rajab, an Indonesian local rice variety. Genetic map was constructed using an F2 population from a cross between TN-1 and Untup Rajab, and SNP markers from RiceLD SNP Chip. Phenotyping was performed using bulk seedling test on F2:3 seedlings against two BPH populations, i.e. X1 and S1. Four QTLswere identified on chromosomes 5, 6, 8, and 11 with PVE values of 7.63%, 9.40%, 17.66%, and 3.05%, respectively. Relatively normal distribution of resistance phenotype and the relatively low PVE values indicate that Untup Rajab has a quantitative resistance to BPH with two different resistance loci identified for each BPH test population. The QTL on chromosome 8 overlaps with OsHI-LOX gene, which is associated with resistance to BPH, and adjacent to another QTL for resistance to green leafhopper. The QTL on chromosome 6 was found near OsPLDα4 and OsPLDα5 genes which are related to BPH resistance. Meanwhile, the QTL intervals on chromosome 5 and 11 did not overlap with any known BPH QTLs or genes, which make them attractive candidates for novel BPH resistance gene discovery.