Difference Analysis and Application in DUS Testing of Grain Quality Characteristics of Rice New Varieties for DUS Testing

Based on the DUS testing experiment, the difference of eight main grain quality characteristics of 23 rice applicant varieties and their similar ones were statistically analyzed in 2 continuous years. A significant difference was found among varieties on each of the eight grain quality characteristics, and the variation coefficients of these grain quality characteristics were ranked in the order of chalky percent, chalkiness, alkali value, amylose content, gel consistency, head rice, milled rice and brown rice. The variation coefficient of head rice, chalky percent, chalkiness and amylose content of conventional rice varieties were obviously higher than those of hybrid ones. Significant differences were found on at least 3 of the eight grain quality characteristics for each of the 4 pairs of rice DUS testing varieties with difference on only 1-2 characteristics according to the DUS testing results. All the eight grain quality characteristics in this experiment met the UPOV requirements as DUS testing characteristics and could be listed as the complimentary characteristics in the rice DUS testing guideline.