Pola Segregasi Ketahanan Populasi F2 Padi Ciherang/Swarnalata Terhadap Wereng Batang Cokelat

Brown planthopper (BPH, Nilaparvata lugens Stål) is a serious pest of rice that significantly decreasesrice yield in Indonesia. Planting resistant varieties is an easy, inexpensive, effective, environmentally friendly, and in accordance with the concept of integrated pest management, and hence breeders continuously attempt todevelop resistant varieties to this pest. The objective of this study was to determine the resistance segregation of F2 plants derived from Ciherang/Swarnalata cross. The study was preceded by selection of candidate parents and followed by an evaluation of test method developed for individually potted and infested seedlings on artificial segregating populations.Standard seedbox mass screening technique of twelve differential and improved rice varieties consistently identified Ciherang and Swarnalata as susceptible and resistantto BPHpopulations originated from Klaten (Central Java) and Banyuwangi (East Java), respectively. Resistance evaluation of artifical F2and BC1F2progenies of Ciherang/Swarnalata crossusing individually potted and infested seedlings method could demonstrated that the segregation patterns of artificial progenies were in accordance with the mixture ratios of resistant and susceptible varieties, i.e. 3 : 1 or 1 : 3 and 1 : 1 assuming inheritance pattern of monohybrid dominant or recessive in F2 and monoybrid dominant BC1F2 populations, respectively. Resistance test of 125 F2 plants derived from Ciherang/Swarnalata cross using the developed test method showed that the plants segregated into 3 : 1 ratio for resistance and susceptible, indicating that BPH resistance in the donor parent was controlled by a single major dominant gene. The resistant F2 plants needs to be confirmed by molecular markers to ascertain the introgression of the resistance gene and tested for their resistance in advanced generation

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

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

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

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