Second, both iR900-Pi9 and iS1000-Pi9 showed rather a high percentage of blast infection on panicle neck in the field nurseries, 20 and 95.6%, respectively (He et al., 2020), implying that a single Pi9 gene is not effective for blast control in the background of R900 and its hybrid Super 1000. This evidence concerns the gene SERPINB9 and infection.