Figure 1

Frequency distributions of days to heading (DTH) under natural day-length conditions in BC₄F₂ populations. The 366 BC₄F₂ progenies were derived from crosses between Koshihikari (KSH) and 11 diverse accessions of Asian rice. Abbreviations of rice accessions are defined in Table 1. X-axis indicates parental accessions and BC₄F₂ populations, Y-axis indicates DTH, and Z-axis indicates the number of individual plants. Bars indicate DTH of KSH (blue), of the other accessions (red) and of backcrossed populations (shaded). DTH was defined as the number of days from sowing to the appearance of the first panicle of individual plants.