<p>Brown planthopper is one of the most destructive insect pest of rice in Indonesia and other Asian countries. Pyramiding some brown planthopper resistance genes is a valuable approach to create more durable resistance against the pest. The objective of this study was to identify polymorphisms of Brown Planthopper Resistance genes (Bph) on 20 genotypes of rice, and to obtain genetic relationship among genotypes tested. The experiment was conducted from June to September 2012 at Green House and Laboratory of Plant Analysis and Biotechnology, Faculty of Agriculture, Universitas Padjadjaran, Jatinangor. Twenty genotypes were analyzed, and two of them were used as check varieties. Simple Sequence Repeat (SSR) markers were applied to detect Bph3, Bph4, Qbph3, and Qbph4 genes. Polymorphic levels were analyzed by calculating PIC (Polymorphic Information Content). The grouping of rice genotypes were done based on principal components analysis (PCA) of SSR data, and the genetic relationship based on the presence of Bph genes was estimated using UPGMA (Unweighted Pair Group With Arithmetic mean). Results showed that RM313, RM8072, RM8213, RM5953, RM586, and RM589 markers were polymorphic. Rice genotypes PTB 33, Diah Suci, Cibogo, Cisantana, Digul, Ciherang, Inpari 13, Inpari 10, and Memberamo had Bph3, Qbph3, Bph4, and Qbph4. Meanwhile Bph3, Qbph3, and Bph4 were supposed to be belonged by IR 64, Aek Sibundong, Batang Gadis, IR 66, and Mekongga. Kalimas and Tukat Penatu had Bph3, Qbph3, dan Qbph4. IR 74 had Bph3 and Qbph3, and Fatmawati had Bph3 and Bph4. UPGMA clustering resulted in two main clusters, in which the first cluster consisted of 2 subclusters. PTB-33 was closely related with Memberamo, Tukat Penatu, Digul, Diah Suci, and Kalimas. The SSR markers used in this study were proven to be valuable in molecular detection of Bph genes and in estimating genetic relationsips of rice genotypes. PTB-33 was a good donor of resistance genes, as well as Memberamo, Tukat Penatu, Digul, Diah Suci, and Kalimas which were identified as promising donors in rice breeding resistance to brown planthopper. </p><p><strong>Keywords :</strong> Bph gene, Brown Planthopper, Genetic relationship, SSR markers.</p>
Directional upgrading of brown planthopper resistance in an elite rice cultivar by precise introgression of two resistance genes using genomics-based breeding
