Isolasi Fragmen Gen pib sebagai Gen Ketahanan terhadap Penyakit Blas pada Padi Sigudang (Oryza sativa L.) dari Kabupaten Mandailing Natal

Abstract

The main disease that assaults rice plants is blast disease, it is caused by the fungus Pyricularia oryzae Cav. Harvest failure due to blast disease occurs in almost of all rice production centre in Indonesia and it results in losses ranging from 10-30% of the annual rice harvest. Control of blast disease in rice plants can be done by using blast-resistant varieties. One of the local rice varieties of North Sumatra has been identified as resistant to blast attack which is Sigudang rice and it carries a blast resistance gene, the pib gene, which encodes proteins containing nucleotide binding sites (NBS) and leucine-rich repeats (LRRs). This research was conducted to isolate and sequence the nucleotide fragment of the pib gene so that it can be used for rice plant breeders to assemble rice varieties that are resistant to blast disease. The research began with growing rice seeds, isolating genomic DNA, isolating pib gene fragment by pib-specific primers, and sequencing. The result is a pib gene fragment with a nucleotide sequence measuring 310 bp. BLASTn results showed that the pib gene fragment from Sigudang rice had 98.99% similarity with the pib gene sequence from Oryza sativa Indica (MZ846152.1) from the Genbank database. Dendrogram analysis of the pib gene nucleotide sequence from Sigudang rice with pib gene nucleotide sequences from other rice in genbank clustered at a genetic distance of 0.20412.