Objective  Effects of different fruit-bagging pouches on the coloration and the expression of the gene related to anthocyanin synthesis in kiwifruits on low latitude lands were studied.

  Method  Composite, yellow-, black-, and white-colored pouches were used to bag the Hongyang kiwifruits in an experiment. Variations caused by the treatments on the chlorophyll, flavonoids, and color in the mesocarp as well as those on the anthocyanin, soluble sugar, soluble starch, color, and expression of the gene related to anthocyanin synthesis in the endocarp at different growth stages of the kiwifruits were monitored.

  Result  The anthocyanin content and colorimetric a, h, and L in the endocarp of the kiwifruits bagged in the white pouches were significantly lower than those of the fruits enveloped in the black or composite pouches. The chlorophyll in mesocarp was higher and the expressions of the anthocyanin synthesis genes AcCHI, AcDFR2, and AcF3GGT1 the lowest during several sampling periods. The fruits bagged in the composite pouches contained significantly more anthocyanin in the endocarp and less chlorophyll in the mesocarp with corresponding a, b, and chromaticity angle than those in the other kinds of pouch. The fruits also had a higher soluble sugar content in the endocarp and mesocarp, and a significantly higher expression level on AcF3GT1 in the endocarp, except on the 140 d. Overall, the degrees of the effects on coloration and gene expression of the kiwifruits by bagging with the yellow or black pouch lied in between those with the white and the composite pouches.

  Conclusion  Kiwifruits bagged in the composite pouches had a chartreuse-colored pulp and a more reddish colored endocarp with lower chlorophyll but higher anthocyanin content than those in the other kinds of pouch. The significantly elevated AcF3GT1 expression by any of the bagging treatments suggested an important role the gene might play in the anthocyanin synthesis in the fruits.