2.2. Measurement of sugar and acid contents
Citrus supernatants prepared using a juice extractor was
injected into a sugar and acid content analysis device (NH-2000,
HORIBA, Japan) to measure the contents. Sugar contents analysis
using refractive index and acid contents analysis using electric
conductivity. The refractive index was measured by using spectrum D of visible light. Statistical significances on comparisons of
all results between control and mutant samples were made by
using a nonparametric test (Wilcoxon test) with P < 0.05 (SPSS,
ver. 12.0; SPSS Inc., Chicago, IL, US).