Detection of Xa-27 gene in rice progenies F₄ from hybridization of tinggong / IRBB27 and its resistance to bacterial blight

Tinggong, one of Acehnese rice variety which has long-life span, low production, high stems, and susceptible to bacterial blight (BB). To improve its performance, Tinggong has been crossbred with IRBB27 which has resistance gene (Xa-27) to BB. Five genotypes (T₂, T₃, T₁₀, T₁₈, T₂₂) of F₄ from the cross were used in this research. The existences of Xa-27 gene in the plants were detected molecularly using dominant STS (Sequence-Tagged Site) marker M964e. Phenotypic analysis of plants resistance to BB were performed by inoculation of Xoo strain IV and VIII at 15 DAT and analysed their lesion at three weeks of inoculation. Prospective genotypes were identified based on their agronomic characters. The results showed that from 60 plant samples observed, 47 plants (78,33%) from the cross inherited Xa-27 gene, and 34 plants (56,6%) showed resistance to both Xoo strain IV and VIII. The study also revealed that there were 8 plants from this genotypes has potential to be developed. These plants showed resistance to both Xoo strain IV and VIII, harvesting time from 108-116 days after sowing, with estimated production from 6,3-9,4 ton ha^-1. These genotypes were T_2.10 ; T_3.12; T_10.9; T_18.1; T_18.2; T_18.7; T_18.10 and T_22.3.