Abstract
QTL analysis using chromosome segment substitution lines (CSSLs) derived from Sasanishiki(SA)/Habataki(HA) has carried out to identify the locus participate in ozone-induced yield decrease in rice. The 39 lines of CSSL and their parental cultivars were grown under ozone-exposure (77 ppb) or ambient air (32 ppb) conditions. Ozone-induced visible leaf injury was detected in SA, and photosynthetic rate, stomatal conductance, transpiration rate were not different. Total grain yield was decreased in HA by ozone. Measurement of compositional units of grain yield showed that culm length, first branch number, filling rate and 1000 seed weight were decreased by ozone in HA, suggesting, these involve in ozone-derived yield decrease in HA. QTL analysis of CSSLs showed a loci located at chromosome 6 involve in the increase of first branch number in the ambient air condition but not in plants grown in ozone-exposed condition, suggesting, yield decrease in HA by ozone might be result in decrease of first branch number derived from the change of activity of genes located at chromosome 6. This work is supported by the Global Environment Research Fund (Ba-086) of the Ministry of the Environment.
