Detection of elevated CO₂ responsive QTLs for yield and its components in rice

Abstract

A mapping population of IR24 (indica) chromosome segment substitution lines (CSSLs) in Asominori (japonica) background was used to detect quantitative trait loci (QTLs) for response to elevated CO2 in yield and its components of rice in free air CO2 enrichment (FACE, atmospheric CO2 plus 200 ìmol CO2• mol-1) and natural atmospheric CO2 (Ambient) conditions. Transgressive segregation and continuous distribution in the CSSLs were observed for elevated CO2 response values (the value in FACE minus that in Ambient), in panicle number per plant (PN), grain number per panicle (GN), 1000 grain weight (GW) and yield per plant (YD), suggesting that all the tested traits responding to elevated CO2 were quantitatively inherited. Three (qYD-1, qYD-10, qYD-12), two (qPN-5, qPN-10) and one (qGN-1) QTLs were detected for CO2 response to YD, PN and GN, respectively, but non-QTL for GW. Interestingly, both qYD-1 and qGN-1 were located at the same marker interval of C112-C2340, on chromosome 1, and had all positive response values from IR24. The results might be useful for understanding the genetic basis for responding to elevated CO2 and breeding new rice varieties adapted to the higher atmospheric CO2
environment in the future.