Agronomic Traits for High Productivity of Rice Grown in Aerobic Culture in Progeny of a Japonica Cultivar and a High-Yielding Indica Cultivar

Aerobic rice culture is a promising way to save water and achieve a high yield. The present study was conducted to identify the agronomic traits required for high rice productivity in aerobic culture using chromosomal segment substitution lines (CSSLs) obtained as progeny from the cross between Sasanishiki (japonica), as the recurrent parent and Habataki, a high-yielding indica cultivar with high spikelet production ability, grown under flooded and aerobic conditions in 2009 and 2011. Grain yields of the CSSLs in aerobic culture were similar to or higher than those in flooded culture in 2009, but were similar to or lower than those in flooded culture in 2011. There were significant effects of genotype and water environment on grain yield in both years. Most of the CSSLs had a higher grain yield than Sasanishiki in aerobic culture, whereas their average was close to that of Sasanishiki in flooded culture. Rice plants grown in aerobic culture had larger biomass production, which enabled most of the CSSLs to produce more spikelets per unit area and maintain single-grain weight, thereby producing a higher grain yield than Sasanishiki. These results suggest that high spikelet producing ability would promote high grain yield in aerobic culture