Introduction. Chinese jujube originated in China and has become a leading fruit tree in the northern part of China with total production of 4,250,000 t in 2009 and total planting area of 1,500,000 ha. Among the reported 944 Chinese jujube cultivars or strains, 'Zanhuangdazao' is the unique natural triploid cultivar; it is characterized by big fruit, high yield and good adaptability compared with the other diploid cultivars. Therefore, our group began polyploid breeding through colchicine induction starting in 2000. Cultivar origin.;Chenguang. is a new Chinese jujube cultivar induced by colchicine on the stem apex of the diploid Linyilizao'. Through three years of top-grafting and purification, its characteristics were observed in grafted and top-grafted experimental orchards continually. in 2009, Chenguang' was released by the Hebei Forestry Cultivar Examination and Approval Committee and became the unique tetraploid Chinese jujube cultivar in the world to date. Cultivar characteristics. The somatic chromosome number, botanical character, phenological phase, productivity and adaptability are given. 'Chenguang' is suitable for growing in Shanxi, Hebei, Shandong Province, where the annual average temperature is 12-14 degrees C and rainfall is above 400 mm, or similar soil and climate conditions. Main cultural techniques. Propagation, the training system, fruit setting and disease control are explained and recommended.
