Inheritance Analysis and QTL Mapping of Rice Starch Viscosity (Rapid Visco Analyzer Profile) Characteristics

The rice starch viscosity characteristics, which can be indicated by Rapid Visco Analyzer profile (RVA profile), have been proved useful for the evaluation of cooking and eating quality in rice breeding program. To study the inheritance of the RVA profile, an F2 population of Wuyujing 3/Aichi 106 was used. The results indicated that the peak viscosity (PKV) was a typical quantitative character, and the hot paste viscosity (HPV), cool paste viscosity (CPV), setback viscosity (SBV), breakdown viscosity (BDV), and consistence viscosity (CSV) might be controlled by one major gene and several minor genes. To elucidate the genetic basis of the paste viscosity characteristics, a recombinant inbred line (RIL) population derived from Nikken 2/Milyang 23 and its genetic linkage map were used to map the QTLs controlling RVA profiles in 2005 and 2006. A total of 34 QTLs distributed on chromosomes 1, 2, 3, 4, 6, 7 and 8 were detected, including 19 and 15 QTLs in 2005 and 2006, respectively. Eight QTLs were both detected in the two years, qHPV6, qCPV6, qCSV6, qSBV6, and qBDV6 were located on chromosome 6, while qHPV2, qCSV2, and qCPV2 were on chromosome 2.