Resistance Spectrum Analysis and Breeding Utilization of Rice Blast Resistance Gene Pigm-1

Rice blast is one of the most important diseases of rice, causing significant economic losses to agricultural production. A new gene, Pigm-1, which is allelic to Pigm, was cloned from Shuangkang 77009 using map based cloning. However, it is unclear whether there is a difference in the resistance spectrum between Pigm and Pigm-1. In this study, using 195 rice blast isolates collected from different areas of the Fujian Province, the Pigm-1 and Pigm single gene lines were inoculated to test their resistance. There was only one blast fungus JL-37 that showed a differential response in Pigm and Pigm-1 single gene lines, while the remaining 194 showed no difference. To further explore the application range of Pigm-1, the resistant rice R20-4 containing Pigm-1 was used as the donor, and a sensitive sticky rice S19-118 was used as the receptor. The hybrid F₁ was first backcrossed with S19-118 using a molecular marker-assisted selection breeding method, and a strain containing the Pigm-1 gene was selected to continue to backcross with S19-118 until BC₃F₁. A new blast resistance rice material, Xiannuo 23, containing Pigm-1 was developed and confirmed by laboratory and field tests. This material can be broadly used for the future breeding of rice blast resistant cultivars to reduce the loss of rice production.