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, <i>Pigm-1</i>, which is allelic to <i>Pigm</i>, was cloned from Shuangkang 77009 using map based cloning. However, it is unclear whether there is a difference in the resistance spectrum between <i>Pigm</i> and <i>Pigm-1</i>. In this study, using 195 rice blast isolates collected from different areas of the Fujian Province, the <i>Pigm-1</i> and <i>Pigm</i> single gene lines were inoculated to test their resistance. There was only one blast fungus JL-37 that showed a differential response in <i>Pigm</i> and <i>Pigm-1</i> single gene lines, while the remaining 194 showed no difference. To further explore the application range of <i>Pigm-1</i>, the resistant rice R20-4 containing <i>Pigm-1</i> 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 <i>Pigm-1</i> gene was selected to continue to backcross with S19-118 until BC₃F₁. A new blast resistance rice material, Xiannuo 23, containing <i>Pigm-1</i> 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.