Abstract:

The rice starch viscosity profile, also termed the RVA profile, is a paste curve of rice flour when the paste is subjected to a standard temperature- programmed heat-hold-cool-hold protocol. The RVA profile has proved to be useful for the evaluation of eating and cooking quality in rice breeding program. In order to understand the genetic basis of the paste viscosity characteristics, the recombinant inbred line populations derived from Zhenshan 97B/ Milyang 46（ZM-RIL）and its genetic linkage map were used to map the QTLs controlling starch pasteviscosity which could be expressed by five parameters: peak viscosity (PKV), hot paste viscosity (HPV), cool paste viscosity (CPV), breakdown viscosity (BDV) and setback viscosity (SBV) in two environments, Hainan and Hangzhou. The results indicated that among 9 QTLs with significant main effects for the five traits the qPKV5 was located on chromosome 5 while all others were located on chromosome 6. For each trait, a QTL flanking RM197-RZ516 on chromosome 6 with which Wx gene was in the same region was detected. QTLs at RM197-RZ516 for PKV, HPV, CPV and BDV were detected to show positive significant G×E interaction effects in Hainan environment. 10 pairs of epistatic effects involving QTLs for the five traits were detected, but no epistasis×environment interaction effect was found.

Key words: Rice, RIL population, QTLs mapping, Epistasis effects, G×E interaction effects, Starch pasting viscosity