Isolasi Fragmen Gen PI-D2 Sebagai Gen Ketahanan Terhadap Penyakit Blas pada Padi Siporang (Oryza Sativa L.) dari Sipirok

Abstract

Blast disease is through by the fungus Pyricularia oryzae, which is characterized by rhombus-shaped spots with pointed ends that are gray or whitish in color on the leaves of rice plants. Some rice varieties in Indonesia are resistant and some are susceptible to blast disease. One of the resistant varieties to blast disease is Siporang rice from Sipirok, South Tapanuli Regency, North Sumatra Province. This resistance is due to the presence of resistance genes that cause immunity to pathogen attacks. One of the resistance genes to blast disease found in Siporang rice is the pi-d2 gene. The pi-d2 gene is a single copy gene located on chromosome 6 and encodes a receptor-like kinase (RLK) protein that is resistant to abiotic and biotic stresses. This study aims to isolate and sequence the nucleotide of pi-d2 gene in Siporang rice from Sipirok, North Sumatra. This study began with growing rice seeds, isolating DNA, amplifying pi-d2 gene fragments with specific primers and sequencing. The pi-d2 gene fragment from Siporang rice has been successfully isolated and sequenced with a nucleotide sequence size of 730 bp. BLASTn analysis showed that the pi-d2 gene fragment from Siporang rice has a similarity value (Identity) of 99.86% with the pi-d2 gene from Oryza sativa Indica Group cultivar Yixiang1B. Dendrogram analysis showed the nucleotide sequence of pi-d2 gene from Siporang rice clustered with pi-d2 genes from Oryza sativa f. spontanea MV 89-80, Yixiang1b, IR36 and Azucena in the genebank collection by a genetic distance of 0.002.