Abstract: Three different pollination methods were used to observe the self-compatibility and some biological effects from Citrus grandis‘Duweimiyou’. The results indicated that Citrus grandis‘Duweimiyou’showed incompatibility under the condition of normal self-pollination, and most of the fruitswere seedless; the
fruit shape index decreased gradually in fruit ripening, the central column was hollow, the fruit-top peel was gradually thinned, and sac cracking was substantially produced while the peel on fruit top dehisced slowly,and fungi invasion made the flesh lose edible value; Self-pollination at bud stage could solve the self-incompatibility in a certain extentwhich p roduced a few seeds, it effectively prevented fruits from growing disproportion in lateral and longitudinal, it also helped the central column of citrus fruit to maintain the solid state, and enhanced thickness of the fruit top peelwhich could significantly decrease fruit and sac cracking; Cross-pollination with Citrus g randis‘Guanximiyou’, the seed number of Citrus grandis‘Duweimiyou’increased significantly, the change of fruit shape index was relatively limited, the central column was solid, fruit and sac cracking were less, but the edible quality was affected.

Key words: Citrus, Citrus grandis‘Duweimiyou’, pollination method, incompatibility