(1) Northern varieties group This group of varieties was formed in the Yellow River Basin of North China, Northwest China. The tree is drought-resistant and cold-resistant. Its tree posture is generally upright or semi-open, strong and healthy. To short fruiting branches or bouquet fruiting branches results mainly, more than a single flower bud, flower bud overwintering force is low, easy to appear stiff bud phenomenon. Many varieties have no pollen or low self-fruitfulness, and a long dormant period.
(2) Southern varieties of this group of varieties formed in the Yangtze River Basin of East China, Central China and Southwest China. Tree body drought, cold resistance is poor, compared with the northern variety group, its flower buds overwintering ability is stronger, many of these varieties in North China performance yield. Its tree posture is generally more open, strong and healthy, to medium and long fruiting branches mainly fruit, more flower buds. The dormancy period is relatively short.
(3) South European varieties group is from China through Iran, Asia Minor to South Europe after a long period of domestication of varieties. Adaptation to dry summer, strong light, mild winter climate. Because the adaptability of this variety is similar to the northern variety group, so the cultivation in North China generally grows well.