Spektrum Ketahanan Galur Haploid Ganda Turunan IR64 dan Oryza rufipogon yang mengandung QTL Ketahanan terhadap Penyakit Blas (Pir)

Resistance Spectrum of Double Haploid Lines Derived from IR64 and Wild Rice Species, Oryza rufipogon Contained the Blast Resistance QTL (Pir). Dwinita W. Utami, A. Dinar Ambarwati, Aniversari Apriana, Atmitri Sisharmini, Ida Hanarida, Didier Tharreau, and Santosa. This study was initiated to determine the spectrum resistance of the candidate durable blast resistance variety contained the QTL (quantitative trait locus), Pir1 and 2. This QTL was mapped on chromosome 2 detected using the advanced backcross population (BC5) from the wild rice species Oryza rufipogon to IR64. Pir (1 and 2) also established on double haploid (DH) population derived from the selected lines of BC2F3 population, progenies from the same parents. The DH lines were developed to speed up the fixation process of the recessive alleles in the selected lines. Near isogenic lines with different blast resistance genes and combination were used in this study comparing to the DH population on their resistance spectrum using the known avr gene isolates both on green house and field screening. The determination of the resistance spectrum will useful on the prediction of durability of blast resistance gene in DH population. The results of spectrum resistance test in green house and field showed that Pir1and Pir2 segregated on 1 : 1 proportion related with specific respond to blast avr gene PH14 and CM28 resistance. Pir1 was identic to Pi33 or Pi25 and Pir2 to Pitq5 on spectrum resistance.