Abstract: The fruit quality of‘Nianju’tangerine grafted on Citrus limonia and Poncirus trifoliate was studied from Nov. 2006 to Apr. 2009. The results showed that the two rootstocks had significant effect on fruit quality. The number of‘Nianju’fruits on P. trifoliate was larger than that on C. limonia，but the yield of‘Nianju’on C. limonia was higher than that on P. trifoliate. The fruits of‘Nianju’on P. trifoliate had lighter weight and smaller diameter and longitudinal diameter than those on C. limonia. The fruit shape index of‘Nianju’on P. trifoliate rose slightly and that of‘Nianju’on C. limonia decreased slightly after color break. The peak of vitamin C content of‘Nianju’fruit on P. trifoliate was slightly higher than that on C. limonia and appeared about a month later than that on C. limonia. The soluble solids content of‘Nianju’fruit on P. trifoliate dropped slower than that on C. limonia after they amounted to its peak at the same time. The content of reducing sugar，sucrose and total soluble sugar first increased then decreased and the rate of increasing and decreasing showed significant difference between fruits on the two rootstocks. The result of principal component analysis showed that the fruit quality of‘Nianju’on P. trifoliate were better than that on C. limonia and the period of fruits of‘Nianju’on P. trifoliate holding its quality on tree was 30 days longer than that on C. limonia.

Key words: Citrus, rootstock, quality of fruit, storage on tree