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 °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