Genetic Analysis of Heading Time in a Cross between Two Indica Varieties with Inhibitor Genes for Photoperiod Sensitivity

The previous studies showed that an early Indica variety Culture 340 from India carries a gene for photoperiod sensitivity with large effects at the Se-1 Iocus and a recessive inhibitor gene (i-Se-1) for sensitivity as well, causing early heading even under long day conditions (IMUTA et al. 1991). On the other hand, an Indica variety Nanjing 11 from China was also presumed to carry a recessive inhibitor gene for Se-1 gene (ARAKI 1988). The present study was undertaken to determine if these two Indica varieties have the same inhibitor gene for Se-1, by investigating the inheritance of heading timein the F1 and F2 populations of a cross between Culture 340 and Nanjing 11 at Tsukuba in 1990.